Making a Bicycle Fit


Many people who have visited my page presenting my crank length formula have sent me e-mail asking about other facets of setting up a bike.  Several have sent me URL's of other sites and asked my opinions of their advice.  Unfortunately, I have yet to visit a site that provides advice good enough that I could simply provide a link from my site for these people to follow.  So, I have established this page to help answer some of the questions.

Note that this page is entirely about "road" bicycles, either racing, touring, or just general road use, the type bike with "turned-down" handlebars.  I know nothing about ATB's and will make no effort to address them here, although it wouldn't surprise me if some ATB riders will learn something by reading this page.  I also know nothing about recumbents; I get a lot of questions about them, too, but have never even ridden one much less learned what to adjust to make one fit.

While I have the utmost confidence in my crank length formula, I do not claim any special expertise in the general setup of a bicycle for a rider.  In fact, I had been postponing creating this page waiting for someone who knows better to set one up.  Unfortunately, most of what has appeared has been confusing at best and misleading or downright incorrect at worst, so I guess I have to jump in with what little I know.  I hope that readers can take what guidance I can offer and at least learn enough to make better decisions for themselves.

I have set up quite a few bikes for people, including some people of unusual build, with considerable success.  However, I've never done it professionally, and more importantly I've never done it remotely -- it has always been in person, watching the rider take test rides and making judgements on how he could fit better.  As a result, most of what advice I can provide is of a general qualitative nature; I have few actual "formulas" that riders could just plug in for ordering custom-made parts or frames.  Ideally, hopefully someday someone will expand on what I present and provide some rational guidance on setting up a bike, complete with specific data or formulas based on actual experience with different riders.

Finally, one more admission of my shortcomings:  Most of the work I have done on bicycle setups was in the 1970's.  While the basics haven't changed, much of the componentry available has.  Hence, I may prove to be painfully ignorant or even totally unaware of component developments that may impact some of these issues.

As will become evident when reading this page, there are lots of things that need to be adjusted, revised, customized or otherwise optimized to make a bike suit the rider properly.  After stating the objective of a proper bike setup, I have put the factors that relate to the construction of the bicycle frame itself together followed by everything that can be changed by adjusting or replacing components.


Objective

The objective of this entire treatise is to help set up a road bike properly, either for racing, touring, or more relaxed riding.  In all of those cases, what we are talking about is a riding position in which the rider contacts the bicycle at three points: the seat, the handlebars, and the pedals.  In the most basic sense, making a bicycle fit involves adjusting these points in relation to each other.  Once the locations and specifics about those points have been determined, there are other issues that must be addressed to fully adapt the bicycle to its rider, such as frame flex, maneuverability vs. stability, durability vs. weight, etc.

The bicycle must support the rider's weight, and hopefully without causing discomfort.  One might presume that it's the seat that supports the rider's weight, but on a typical road bike that would be an incorrect presumption.  With a correct setup, the rider's weight is divided between his feet, his seat, and his hands.  On a road bike, the torso will be angled forward and there will be some weight on the hands when coasting on level ground.  If you are interested in sitting bolt upright on a bike, this page is not for you.

To fully understand how this setup works, you need to understand the balance involved.  As mentioned above, when coasting the weight is distributed on the feet, seat, and hands.  However, applying force on the downstroke of the pedalling motion has a reaction of lifting the torso, relieving the weight on the hands.  During the type riding being optimized for, the weight on the hands should be fairly low; the force of pedalling should be relieving most of it.  You don't want it relieving too much, because then you'd have to be pulling up on the bars to keep the head down; OK for a sprint, but not good for the continuous ride.

The intention is to make the bike feel comfortable in the type of riding to be done.  On a properly set up racing bike, a rider will feel quite comfortable in his head-down, body-forward position as long as he is pedalling hard, but if he tries to take it easy he will find the weight on the hands a little uncomfortable.  On a properly set up touring or casual-use bike, a rider will feel quite comfortable pedalling relatively gently, but applying full force to the pedals in the sitting position will require pulling up a bit on the bars; not only is this not good for comfort, but that pulling will expend some energy.

In either case, the bicycle should feel far more comfortable to the rider when pedalling than when coasting.  When coasting, the rider should have an urge to pedal, as that would feel better to him than coasting.  For the casual rider, the setup should make him feel like pedalling gently.  For the racer, his head-down, weight-forward position should make him feel like pedalling hard.

How far will the rider bend at the waist?  That entirely depends on his beer gut.  In general, it does not depend on whether his bike is set up for racing or casual riding; if the rider is thin and trim, either setup should result in nearly the same bend at the waist.  Compared to the casual setup, the racing setup has the entire rider rotated forward relative to the bottom bracket; the seat is forward, the handlebars are forward and down.  While the weight is shifted, the bend at the waist is not changed.

Of course, if the rider has a gut, the bike will need to be adjusted for less bend at the waist.  The general idea will be to move the seat forward and the handlebars higher and rearward for either type setup, straightening the waist and ruining the aerodynamics but otherwise maintaining a comparable balance on the three contact points.

As a side note: the need to bend at the waist for a good aerodynamic position on a bicycle means that competitive cycling imposes an additional incentive to be thin above and beyond the need to be fit.  In many other aerobic sports, competitors of a stocky or even pudgy build can compete at the highest levels, but cycling requires its competitors to be skinny.  In an era when the medical profession seems to feel that "heroin chic" represents a proper percentage of body fat, it should be emphasized that cycling success should not be used as a measure of general fitness.  A successful competitive cyclist needs to be fit, to be sure, but others who are equally fit can fail miserably because they don't happen to be as thin.


Frame/Fork Design Variables

Frame Size

The length of the seat tube -- from the bottom bracket up to the opening where the seat post is inserted -- is generally known as the frame size.  In days of yore, everything about the different size frames -- hell, the entire bikes -- of a particular line or manufacturer would be exactly the same except for the length of the seat tube, the length of the head tube, and the angle and length of the seat stays.  Basically, the top tube would remain horizontal as it was relocated upward or downward without changing anything else.  So, when a customer wished to purchase a bike from that line, the only question he needed to answer was "What frame size?"  It is still arguably the most important dimension in choosing a bicycle.

One thing of note:  Back when frame sizes were listed in inches, the dimension was typically measured from the centerline of the bottom bracket to the top end of the seat tube where the seat post is inserted.  Frame sizes that are listed in centimeters are typically measured from the centerline of the bottom bracket along the seat tube to the centerline of the intersection with the top tube.  The difference is about half the diameter of the top tube, about 1.3cm.  So, if you know a frame size in inches, to find the equivalent size in cm you will need to multiply by 2.54 and then subtract 1.3.

The reason for selecting a particular frame size is to establish the height of the handlebars.  Since the top tube stays horizontal in all but the most unusual road bikes, the frame size determines the range of height of the handlebars above the ground.  The handlebar stem attachment only provides perhaps an inch of adjustment up or down, so starting with a frame size at least close to correct is essential for establishing the handlebar height.  By comparison, the seat post can slide up and down several inches, far enough that any frame size within 15 cm or so of correct could hold the seat at the correct height.

Of course, there are other things that can be done to correct handlebar height when the frame size is wrong, including using an unusual shaped stem or different handlebar bend -- or even simply turning the handlebars upside down!  But if you want the bike to fit right, the best thing to do is to start with the right size frame.

The implications of this choice should be evident.  Serious racers want to be low for aerodynamics and to maximize force on the pedals, so they want low handlebars -- and therefore a relatively short frame size.  People interested in more relaxed riding or touring will probably want their handlebars a bit higher for visibility and comfort, and therefore will prefer a taller frame size.

I have no magic formula to offer.  There is no shortage of formulas from others; you can check Edward C. Zimmermann's Competition Road Racing Bicycle Size/ Proportions Analysis site for several.  In general, I would expect that any formula that bases frame size on inseam length is probably a good guideline.  It is probable that most framemakers have derived their formulas based on experience with serious racers, so if you're interested in a relaxed riding position you might want to take that into consideration and lean a little toward the tall side from whatever their formulas call for.

Note that when using 700C wheels, selecting a frame size shorter than about 50 cm simply won't do any good.  Companies offer shorter frames, but due to the diameter of the front wheel the head tube is already as short as it can get so they slope the top tube.  This gets the seat lower, but doesn't lower the handlebars.  The top tube (discussed below) can't get much shorter, either, meaning that the handlebars can't be brought back towards the seat.  The result is a bike that a short rider can climb onto but will never be comfortable riding.  Riders who need a frame shorter than 50 cm are therefore advised to seek a bicycle fitted with 650C wheels.  These smaller wheels allow a more conventional frame geometry, just scaled down to be comfortable for the smaller rider.

Several bike manufacturers offer 650C bikes designed for shorter riders, including Cannondale with their "Compact" models down to 43 cm.  A diminuitive friend of this author purchased a Cannondale, and it came with small handlebars, small brake levers, and a small seat.  Unfortunately, it also came with a 165 mm crank and gearing suitable for a gorilla, but all that was rectified easily enough.  You might ask before you buy, and perhaps talk them into keeping their crank and credit you for the cost so you can find yourself a crank more suitable for your size.

Note that Cannondale and others also offer 650C bikes that are not intended for short riders.  Such bikes are offered in frame sizes up to 62 cm and are designed to take advantage of the lighter weight, better aerodynamics, and closer drafting spacing that come with the smaller wheels.

Hogwash:  To determine frame size, some bike shops have you stand over the bike and check the clearance between the top tube and your crotch.  I'm sorry, but crotch clearance is only important to those who plan to spend a lot of time standing over their bikes.
 

Seat Tube Angle

In general, the seat tube angle should be selected based on the type riding expected.  Those who plan to race will want an aerodynamic position that allows them to apply maximum force to the pedals without having to tire themselves yanking on the handlebars, so they want the seat forward and the handlebars forward and down.  This position puts a lot of weight on the hands; since pushing down on the downward pedal lifts the torso, having a lot of weight on the hands encourages pushing hard.  It also takes weight off the seat, allowing the use of a puny little seat to save weight at the top of the bike where it counts most.  Setting up such a riding position calls for a "steep" seat tube angle to help position the seat forward.  A seat can be adjusted forward and back an inch or so on its mount for fine tuning.

The rider looking for a more relaxed riding position will want the bars higher and rearward and the seat rearward.  This will take weight off the handlebars and put it on the seat.  Due to the leverage difference resulting from the increased horizontal distance between the bottom bracket and the seat it will require less force on the pedals to lift the torso and take all weight off the hands, so this position is more suitable to cycling of a less-forceful nature.  Setting up this relaxed position will call for a shallow seat tube angle to help position the seat rearward.

One other valid reason for varying seat tube angle is for riders that have unusual proportions in their legs and feet.  If their upper leg is unusually short compared to their lower leg, for example, that might call for a slightly steeper seat tube angle.  If their feet are unusually long for their leg length, that might call for a slightly shallower seat tube angle.  In actuality, however, these variations are likely to be slight enough that they can be dealt with in the fore/aft adjustment of the seat itself.

Hogwash:  Many framemakers insist that the seat tube angle should vary with the frame size, generally opting for a shallower angle with taller sizes.  Not really hogwash, I guess; it's a perfectly viable corrective action to make taller riders as comfortable as possible when using cranksets that are too short for their size.  But a far better idea is to fit the bike with a properly-sized crank, which will eliminate any need to vary seat tube angles with frame size.
 

Bottom Bracket Height, or Drop

The bottom bracket height is the vertical distance from the road surface to the centerline of the bottom bracket.  The "drop" is the vertical distance from the centerline of the bottom bracket to the level of the axle centers of the wheels.  Obviously, the two are related: the bottom bracket height is one half the tire diameter minus the drop.  Framemakers usually talk about the drop, since there's no telling what diameter tires you might choose to mount.

In general, what you are trying to establish is cornering clearance.  In racing, cornering clearance is critical; you don't want to be coasting through a corner while everyone else in the peloton is pedalling.  For relaxed riding or touring, cornering clearance is less important, but nobody likes their pedals banging the ground when they don't expect it.

A higher bottom bracket provides more cornering clearance, but just about every other effect is bad.  Since all the other adjustments are relative to the bottom bracket location, having a higher bottom bracket means everything is higher, including the rider himself.  The frontal area increases, increasing the aerodynamic drag.  The center of gravity moves upward, making the bike less stable and less maneuverable.  It's even a bit harder to get on and off the bike.

Cornering clearance is affected by many things, including crank length, crankset width (including spindle length), pedal width, pedal design, and bottom bracket height.  The shoe design might even come into play, if the outside toes hit the ground before the pedal (ouch!).  What the racer really wants to do is to position the pedal at bottom of stroke as low as possible while still maintaining adequate cornering clearance, so he must consider all of these factors together when specifying the drop desired.

Quite obviously, you need to decide what length crank you are planning to use before you specify the frame drop -- see my crank length formula page.  Unfortunately, frame designers generally do not take such variations in crank length into account when designing their frames, and provide all frame sizes with the same drop or vary it only a few mm.  As mentioned on my page describing the implications of using properly-sized cranks, the drop should decrease by the same amount that the crank length increases, possibly even a hair more.  If you are unusually tall or short and plan to use a crank sized accordingly, you will have to convince a framemaker to provide what he considers an unusual drop.

Note that according to Edward C. Zimmermann's Competition Road Racing Bicycle Size/ Proportions Analysis site, there are regulatory limits on bottom bracket height in racing.  My own opinion on such regulations is covered on my Old Wive's Tales page.
 

Top Tube Length

The top tube length contributes to the distance from the seat to the handlebars, and therefore should vary with the rider's size.  Both arm length and torso length figure into the proper distance from seat to handlebars.  After the frame is constructed, the distance from seat to handlebars can be adjusted by replacing the stem.  However, use of a stem shorter than 40mm or longer than 140mm is problematic, so it is of some importance that the top tube length is at least close to correct.

Since riders with longer legs usually also have longer arms and torsos, it would make good sense if the top tube length varied in proportion to frame size.  Unfortunately, such variation is almost unheard of; most framemakers are more concerned with making the wheelbase as short as possible regardless of frame size.  As a result, most tall and short frames have the same wheelbase -- and the same top tube length -- as average-sized frames made by the same manufacturer.  This results in short riders needing very short stems to be able to reach their handlebars and in tall riders having to install very long stems to ride their unstable bicycles.

There's actually not a lot the framemakers can do to help the shorter riders, since they can't make the top tube shorter without causing interference problems between the front wheel and the down tube or the rider's toes.  Shorter riders would be well advised to consider bicycles with 650C wheels, as mentioned in the discussion of frame size above.

Framemakers could help the taller riders, if only they can get off the minimum weight/minimum wheelbase mentality and provide a geometry that will perform properly for taller riders.
 

Chainstay Length

The chainstays are the tubes from the rear dropout to the bottom bracket.  In general, it is preferable if they are short; shorter chainstays make the wheelbase shorter, which makes the bike more responsive.  Shorter tubes are also stiffer, so shorter chainstays make the frame either stiffer or lighter depending on how you choose to take that benefit.  And shorter chainstays tend to shift the weight of the rider more on the rear wheel and less on the front wheel.

However, there are disadvantages to shorter stays.  For one thing, the chain alignment suffers in some of the misaligned gears.  If sprockets are aligned, they are aligned; but if you select a gear in which the front sprocket in use and the rear sprocket in use don't happen to line up perfectly (most don't -- in fact, only two speeds on a typical ten-speed will) then shorter chainstays will increase the angle of misalignment.  For this reason alone, many serious touring bicycles have been designed with long chainstays since tourers like to make use of a wide range of gears.

Another disadvantage is tire clearance.  With long chainstays, the fat end of each stay can be securely attached to the bottom bracket and then move apart and thin down to allow clearance for the tire.  As a result, enough clearance can be provided for big, fat tires for touring on poorly-maintained roads.  With short chainstays, the chainstays attach to the bottom bracket so close to the tire that there's no room to finagle a lot of space for a tire; the frame may limit installation to only narrow racing tires.  Note that vertical dropouts help in this department in that the wheel doesn't have to move forward to come out of the dropouts and therefore requires less clearance near the bottom bracket, but vertical dropouts have other concerns including an inability to adjust wheel alignment.

Some framemakers have been known to curve the seat tube a bit to allow the chainstays to be made very short, bringing the rear tire right up against the back side of the bottom bracket.  This is simply a case of getting carried away, and has no purpose other than to separate the customer from his money when he's dumb enough to select a frame by picking the shortest available wheelbase.
 

Head Tube Angle

This is actually the angle of the steering axis.  It is usually the same as the seat tube angle; racers will prefer the steeper angle because it makes the bike more maneuverable, while the relaxed rider will prefer the shallower angle for more stability.
 

Fork Rake

Forks are "raked", meaning the blades are curved to locate the front axle forward of the steering axis.  It would seem logical that more rake would increase stability, but in fact the opposite is true; the fork with minimal rake provides the most stable handling.  Little or no rake results in a bicycle that almost rides itself, while an extreme amount of rake results in a bike that's difficult to control.

The reason the rake is achieved by bending the fork blades into a gentle curve is to absorb shock efficiently; the curvature of the blades allows them to flex evenly over their entire length when absorbing road shocks.  There are forks available that use straight blades and achieve the necessary rake by via an angle at the crown, but this results in the stresses caused by road shocks to be concentrated at the crown.  The crown will have to be beefed up to avoid premature fracture.  Hence, you'll end up with a fork that is both heavier and stiffer than the curved variety.  And the increased stiffness can be expected to have adverse effects on the front tire, the front wheel durability, the headset bearings, the frame, and the stem, so all of them will need to be beefed up as well to avoid damage.  And for all this, the rider gets more pain in his hands, wrist, and butt, with essentially no benefit.  The manufacturer, however, gets to separate the ignorant from his money.
 

Tire Clearance

It may not seem obvious, but it is possible to design a frame to permit any tire that will fit on a 700C rim to be fitted, or to only permit really skinny racing tires to fit.  There are advantages to the latter idea; by designing the fork crown very close to the top of the skinny front tire and the crossbrace between the seat stays very close to the top of the skinny rear tire, you permit the fitting of brakes with very short, stubby arms.  Such brakes work better -- a lot better.  If you design these parts with enough clearance to allow for big fat tires, then you may have to use brakes that are spindlier and don't work as well.

There are other differences, too.  To fit wider tires, the frame designer may have to neck down the chainstays more -- which will weaken the frame considerably.  Similarly, the fork crown will need to be wider, which adds weight and/or reduces structural integrity.
 

Stiffness

In lugged steel frames, stiffness is simply an issue of how thick the walls of the tubes are.  There are lots of factors involved with different frame designs, though; larger diameter tubes increase stiffness, for example.  Even carbon composite frames can be made in different stiffnesses by changing geometry or adding layers of carbon fiber.

This is a very common place to make mistakes.  There is nothing worse than a "whippy" frame, but it's only too common when cyclists choose frames according to which one weighs the least.  Back in the 70's, there was a common illustration of this problem: Columbus tubing came in two sets, SP and SL.  SL was designed for smaller bikes with lighter riders while SP was intended for larger bikes with heavier riders.  Both were excellent, the best quality available at the time.  However, it became common belief that the SL was the better quality set because it weighed less, and most framemakers -- nearly all, actually -- made all of their frames from SL tubing regardless of size of frame or rider.  Finding a frame made with SP tubing was difficult indeed; you often had to special-order one.

A whippy frame is a real disaster.  In racing, it will sap all your speed; when you "jump", the frame will flex, the bottom bracket will move side to side with each stroke, and it will absorb all your energy and leave you going nowhere.  You find yourself staying in low gears and spinning a lot, because shifting to higher gears just causes the frame to absorb that much more of your energy.  In touring, a whippy frame can actually become unstable and begin oscillating, especially when loaded with lots of heavy gear and sailing down a hill at high speed among traffic.  There is little a rider can do at this point other than to apply the brakes and hope he can regain control before he gets killed.

It is possible to design a frame that is too stiff.  It results in a bike that is "dead"; it feels "inert", it has no spring to it.  If you want to know what this feels like, go find an old Schwinn Varsity (made from welded-together water pipe) and give it a ride.  Meanwhile, it's not too common a problem today, especially if you're spending any sort of serious money on a bike.

A common philosophy in frame design is "heavy bottom, light top", meaning that you use tubing that has very thick walls in the vicinity of the bottom bracket and chainstays but thinner walls for the top tube and the upper end of the seat tube.  This actually works pretty well, as compared to older design "double-butted" tubes that are the same wall thickness at each end and thinner in the middle.  The most important thing is to make sure that the bottom of the seat tube is very stiff, because the seat tube holds the front derailleur.  If the bottom bracket attachment to the bottom of the seat tube flexes under load, it misaligns the derailleur with the chainrings and causes the chain to rub in the cage or possibly even to change rings just when you don't want it to.

Remember that a taller frame made with the same gauge tubing as a shorter frame will be more flexible.  You would have to make a taller frame with thicker-walled tubing just to keep it the same stiffness as the shorter frame.  When you combine this with the fact that the larger rider is also going to be heavier and stronger, you realize that the taller frame should be made with much heavier tubing.  You also realize just how much trouble a really small rider has finding a frame that has any life in it at all, they are all usually far too stiff.  If he happens to find a bike that's lively, he should never allow larger riders to try it out, because it's only too easy for them to damage it.
 

Braze-Ons

Well, we used to call them braze-ons back when frames were brazed together.  I dunno what they're called in this day of carbon composites and bonded aluminum, but the idea is still the same: providing attachment points for whatever is attached to the frame.

A framemaker can simply not provide any attachments, which will result in a very light frame and good sales to people who consider that as all-important.  For those actually constructing an entire bicycle, I advise you to be wary of such shenanigans, since having to provide clamped-on attachments for the accessories you need will add more weight than the braze-on would.  The wise cyclist ordering a custom frame will carefully specify the attachments he needs, but no others because having unneeded attachment points is a waste of weight and money.

A listing of many popular attachment points follows, with choice comments.
 

Cable Guides

You can hold the cable housings to the frame with cute little chrome-plated clamps, or with zip-wraps.  Or you can have suitable guides built onto the frame itself.
 

Cable Stops

The simplest way to route cables is to run the housing all the way from the control to the item being controlled and strap the housing to the frame, as described under "Cable Guides" above.  With a few stops provided, though, you can do away with a lot of the housing and just run the core itself over long expanses.  This will not only save weight, but it will usually result in better response because of less friction and less flex.
 

Shifter Mounts

If you prefer shifters on the down tube, sometimes you can get the posts built onto the frame.  If you decide later that you'd rather have shifters up on the handlebars, you can get cable stops that mount on the shifter posts -- but they look hokey.

See more about shifters under the discussion on components below.
 

Brakes

Simple side-pull brake calipers usually only require a mount hole, convenient in the fork crown and easily provided in a cross brace between the seat stays.  However, some people prefer lever brakes which require a pair of posts.  They also typically require a cable holder above somewhere.  Other variations on brakes, such as a hub brake at the rear, may require some other type of attachment.
 

Water Bottle Boss On Top of Down Tube

 

Water Bottle Boss On Front of Seat Tube

 

Water Bottle Boss On Bottom of Down Tube

Bicycle tourers call this a "fuel bottle"; it's not terribly accessable while riding, but it's a good place to store a container of fuel for stoves or the like when camping.
 

Chain Hanger

Totally worthless when riding, but a convenient little button to hold the chain while you're changing the rear wheel.
 

Pump Holder

If you tour or otherwise travel far enough from home to carry a spare tire or tube, you will probably want to carry a tire pump.  If you use a short frame, you can usually find a "frame fit" pump that jams between the top tube and the down tube along the front of the seat tube.  For taller bikes, though, that would require an excessively long pump, so it's usually a better idea to provide a tang to hold the upper end of the pump.

If you choose the correct pump, you can also use it to clobber dogs that are attempting to bite your leg.  I know of one rider who used one to put several serious dents in a car that had deliberately run him off the road; he managed to catch it in traffic, as well as make a clean getaway after causing several thousand bucks' damage.
 

Fender Attachments

Hey, some people want fenders, especially if they ride to work on rainy days in their work clothes.
 

Luggage Rack/Pannier Attachments

Built-in luggage rack/pannier attachments are much better than the bolt-on kind.  If you plan on touring with heavy bags, this is a must.
 

Generator Mount

If you use a generator, you know that they usually come with mounts that are designed to booger up your frame as much as possible; they not only clamp down mercilessly on a thin seat stay, but they often even come with a little setscrew to dig into the metal.  If you plan to use a generator, you might want to have a mount for it built onto the frame.
 

Kickstand

Some of us actually like kickstands.  If you do, you'd better speak up when buying a frame; most better frames are designed not to use a kickstand, and there is a small strut between the chainstays right behind the bottom bracket.  While you may be able to get a kickstand in there, it will attach via a bolt and retainer that clamps down onto the chainstays.  It will booger up your chainstays big time.  A better idea is to have the strut replaced with a flat built-in plate designed for a kickstand attachment.


Component Variables

Crank Length

See my crank length formula page.
 

Crank Width

The issue of horizontal spacing between the pedals isn't often addressed, but probably should be.  One could presume that the pedals should be as close in on the side of the bike as possible for cornering clearance as well as to minimize the off-center loading caused by pedalling forces; in fact, at least one attempt at the hour record was made with a custom bike that allowed a far narrower crank assembly than usual, bringing the pedals (and feet, and knees) right in close to center.

On the other hand, there may be value in relating the width of the crank assembly to the width of the pelvis.  It would seem logical that a rider would prefer to feel as though he is pressing directly downward on the pedals without any inward or outward factor.  In fact, getting this width right might help avoid knee damage.

If you're small and have narrow hips, there's probably little you can do.  You can install the shortest BB axle you can find, and deal with the chain alignment issues that result.  Obviously, if your feet are narrow, you can also select pedals accordingly (see "Pedal Width" below) which will help.  The very small person is still likely to feel like he's pedalling outward and downward.

If you're also light weight and therefore have crank strength to spare, you could consider grinding the outer face of the crank down to allow the pedal to thread in farther.  You'll probably only get a couple of millimeters on each side with this method, but every little bit helps.

If you're tall, you can install a longer BB axle to space the arms outward.  If you measure the distance from centerline of both arms, you'll probably find that the arm on the right side is farther out than the left -- so, if you can, install an axle that's longer on the left end so that you center yourself on the bike while you're increasing width.  Also, keep in mind that spacing the right crank arm farther out brings up chain alignment issues.

You can gain width by installing wider pedals or spacing your pedals outward, but this will increase the twisting stress on the crank arms.  It is preferable to gain width via a longer BB axle if possible.

Crank Stiffness

Roadies of yore all seemed to presume that cranks were infinitely stiff, just buy the lightest one you can afford.  ATB riders, on the other hand, seem to value a stiff crank above all else.  The ATB guys are on the right track!  Road or ATB, all cranks flex.  And thanks to the load (force on the pedal) being off to one side of the arm itself, the flex is a little bit of down combined with a whole bunch of twist down and inward.  If you're a big guy, or know a big guy, you can watch this flex: apply the brakes hard and push down on a forward pedal.

Unfortunately, the twisting is really bad on the ankles.  The direction that the pedal tilts applies a really nasty twist to the ankle right when it's applying max force.  It also tends to cause the knees to move outward, and applies a really nasty twist to the knee as well.  All bad, bad, bad.  Anyone who purchases a crankset based solely on minimum weight is just asking for joint damage.

As long as you're considering forged alloy cranksets, it's a fairly easy matter to determine which is likely to have the most stiffness: the one with the meatiest arms.  A simple oval cross section is good, something with lots of recesses or holes in the outside surface is bad.  In theory, a massive cross section with a recess on the inside (the side facing the bike) is best, making the cross section a sort of channel shape with the opening inward.

Better yet would be a hollow tubular crank arm, but such cannot be forged; it typically must be welded together, introducing the problem of making reliable welds in production.  This concept does have the advantage of making it easier to make crank arms of different lengths.  In general, such crank arms would be made of Chrome Molybdenum alloy or some such high-strength substance; making a hollow arm out of aluminum would either require such thick walls that being hollow wouldn't be much different than being solid, or such a large diameter that your feet would need to be too much farther out the side of the bike.

When selecting a crank, the trick is to strike the right balance between flex and weight for your build.  If you're a lightweight, you can probably get away with any crank on the market, so you might as well pick a light one.  If you're more massive and muscular, you should be looking for something meaty -- and considering the fact that most cranks on the market value weight higher than stiffness, you'd better be looking for the meatiest thing you can find.  If you're really big and strong, I'd highly advise you avoid road cranks like the plague and select from the market in ATB cranks, which seem aimed at a different market and designed for strength rather than light weight.  They tend to look kind of "industrial", but function is more important than appearance here; your knees will thank you.

Remember that making a crank arm longer also makes it more flexible.  Any company making longer cranks should be taking this into account, making the longer cranks more massive as well.  But that's not happening, so if you're a heavyweight and you need to use a long crank, you need to be carefully selecting a really strong design.
 

Pedal/Shoe Type

These two must be chosen together.  The purpose of a "cycling shoe" is to hold the foot rigid; everything below the ankle should behave as a stiff link.  If the arch of the foot is allowed to flex, then the rider must expend energy in foot muscles holding it rigid when applying force to the pedals.  Most purpose-built cycling shoes are very stiff indeed; some even have metal beams in the soles.  The design of common street shoes is usually the opposite, as having some flex in the sole is helpful for walking comfortably.  People visiting a bicycling event for the first time sometimes get the impression that cyclists must be in extreme pain judging from the stiff way they walk, when in fact they only walk that way due to the shoes they are wearing.

You need to be deciding what type of riding you intend to do.  The more serious rider will want the dedicated cycling shoe with an attached cleat that mates to the specific type of "clipless" pedal he intends to use.  The casual rider may prefer to use some type of pedal that allows him to ride wearing whatever shoes he walked out of his house in, perhaps a pair of sneakers; there are some pedals that will work acceptably well in this fashion, although they tend to be of low quality.  Note: many who have always ridden in "street shoes" simply don't believe that switching to cycling shoes can make all that much difference, but it does!  Ask any cyclist using cycling shoes.  The minute you decide that your bike is going to be ridden regularly rather than simply collecting dust in the garage is when you should start shopping for a pair of cycling shoes.

In today's market, cycling shoes seem to be divided into two general types: road and ATB.  The road shoes are intended to be used while cycling only; they have only a hard shell for a sole, intended to be as light and aerodynamically smooth as possible.  ATB shoes, on the other hand, are designed for the off-road rider who occasionally has to jump off his bike and carry it through the mud or over a log or something.  As a result, these shoes have a sole that is reminiscent of a hiking boot -- toothy for a good grip.  Some models even have replaceable spikes or heel pads.

The sole isn't the only difference between road and ATB cycling shoes, however.  There are several clipless pedal attachment schemes on the market, including Look, Time, Speedplay, and SPD (Shimano Pedal Dynamics).  Most serious road racers seem to prefer Look, with a few preferring Time or Speedplay.  The ATB riders seem to go for SPD almost exclusively.  The cleats used with these various attachment schemes themselves are bolted to the bottom of the shoe in different ways.  The Look cleat attaches with three screws in a broad triangular pattern.  The Time and Speedplay cleats attach with four screws in a broad rectangular pattern.  The SPD cleat is a remarkably tiny little thing that attaches to the sole with two screws right next to each other.

Of course, it'd be nice if the shoes you decide upon happen to have attachment holes on the sole for the type cleats you prefer!  There are all sorts of adapters available, but trying to use a cleat style that the shoe wasn't intended to use is just asking for trouble.  So: if you plan on using ATB style shoes, plan to use SPD-compatible pedals since the shoes will come with the two holes spaced closely.  If you plan on using road shoes, plan to use Look, Time, or Speedplay pedals -- and if at all possible, look into how the cleat attaches before buying.

There are several reasons the ATB riders prefer the SPD style pedals and cleats.  For one thing, the cleat is really small, leaving lots of room on the bottom of the shoe for a tread pattern for stompin' through the mud.  For another thing, the design of the SPD attachment scheme seems to make it fairly resistant to getting jammed up with mud or the like; when you need to get a foot out of the attachment in a hurry, that's important.  Finally, it's really easy to get your foot back on when you get back on the bike; it's almost just a stomp and it's on.  Most SPD pedals are two-sided so you don't even have to roll it over.

Road riders like the Look, Time, and Speedplay pedals for good reasons, too.  The broader cleat design helps distribute the load better over the bottom of the shoe, which generally means that an SPD-compatible shoe will need to have even more stiffness built in to handle the concentrated load.  The broad cleat designs also hold the cleat more firmly; although many of these designs have a built-in amount of freedom of rotation to align the feet, the road styles provide a carefully controlled amount while the SPD's are a bit more sloppy.

All of the cleatless attachment schemes allow you to pull your foot out quickly by simply rotating your heel outward.  This understandably takes some getting used to; some even suggest that you will be falling over sooner or later before you get the hang of them.  You will not be pulling your foot out upward or rearward.

For the casual rider, the ATB shoes combined with the SPD pedals seem to be an excellent choice -- even if you never leave the pavement.  The fact that the shoes have soles usable for walking allows you to go into the convenience store for a snack.  The double-sided pedals are handy.  And SPD pedals are widely available and typically cheaper than the Look, Time, or Speedplay pedals.

If you would rather go cleatless, there are varieties of shoes that provide some stiffness for pedalling combined with a cleatless sole suitable for some walking.  Likewise there are pedals intended for use with such shoes, typically toothy contraptions so the rubber soles of the shoes won't slip.  You can fit a toe clip and strap to the pedal to hold your feet securely, or just a clip to prevent your feet sliding off forward.  Before clipless pedals became all the rage, cycling shoes came with a type of cleat that fit pedals with clips and straps -- and you would not be getting out of those in a hurry, period!  Even without any sort of cleat, getting your foot out in an emergency can be a hit-or-miss proposition in an emergency.  They'll cut off circulation to your toes, too.  Many people ride with the straps loose except when a finishing sprint is imminent.

You can choose to avoid attaching your feet to the pedals, opting instead for "block" pedals that are the same on both sides and you merely jump on and start pedalling.  Some people seem to think this is safer, because they can get their feet off at will.  In truth, at high speed such a configuration can be quite dangerous -- your foot can slip off while standing up and pedalling hard, almost surely causing a disastrous crash.  This ranks right up there with the introduction of seat belts in automobiles, where people didn't think they wanted to be strapped in; regardless of what you think, being strapped into a car or having your feet securely attached to bicycle pedals is the safest way to go.  For casual pedalling around a neighborhood block pedals work well enough, but getting out of the saddle at all is taking a terrible risk.

When weighing options, keep in mind that it's not terribly difficult to change pedals.  You could, for example, use a casual pedal/shoe combination for most of your riding, but when a race weekend approaches you can simply unscrew those pedals and screw in some clipless items and lace up your serious competition shoes.  As long as you use anti-seize compound on the threads each time, you can swap pedals weekly for years without problems.  The bigger problem may be becoming accustomed to the attachment schemes; you don't really want to be doing 30 mph in the middle of a peloton without a good familiarity of how to get your foot disconnected from your pedals in a hurry.

There are also clever little devices that are designed to snap into clipless pedals and provide a platform for sneakers.  The two-sided SPD's provide an interesting possibility: you can leave this little device attached to one side only, so you can ride with sneakers on one side of the pedal and with cleated shoes on the other side.

If you intend to go the fully casual route and wear sneakers, I am sorry to report that the ideal pedal apparently does not yet exist.  I have been waiting for its appearance for decades, and even predicted its appearance in a cycling club newsletter article back in the 70's when we were all using "rat traps" with toe clips and leather straps.  For use with sneakers, it would be a relatively simple matter to design a pedal with a long platform, perhaps 2/3 as long as a rider's foot and contoured to the shape of a shoe's sole, and thereby provide the needed stiffness in the pedal rather than in the shoe.
 

Pedal Width

Just exactly what this means depends on the choice of pedal/shoe type discussed above.  In any case, it refers to the fact that some people's feet are wider than others, and the pedals must vary to match.  In the case of a casual pedal/shoe setup, the pedal simply needs to have a wide enough platform for the shoe to sit on.  It's best not to be too wide, however, since that would decrease cornering clearance.

In the case of clipless pedals, the cleat assembly on the shoe will be the same width for whatever rider is using them, but it will need to be relocated according to the width of the shoe.  For optimum cornering clearance, the inside edge of the shoe needs to be as close to the crank arm as possible without touching it.  The adjustment for this is typically in the cleat-to-shoe attachment; the cleat itself can be slid side-to-side and tightened down in the proper location.

Some pedals have been offered with a variety of different length axles to locate the pedal closer or farther away from the crank arm.  For a rider with a narrow foot, a short axle is used that locates the pedal closer to the crank arm.  For a rider with a wide foot, a longer axle is used to provide enough clearance between the inside of the shoe and the crank arm.  But with the advent of clipless pedals with their side-to-side cleat adjustment, this is not common any more.  It's something to keep in mind, though, if you have a really unusual problem -- unusually narrow or wide feet, or slewfootedness.  You might consider taking a common set of pedals and having a set of axles custom-machined to fit them.  If you get lucky, you might even find that a set of axles from Brand X pedals can be fit into Brand Y pedals, providing the spacing you need.

There is also a product called Kneesavers, which are extension adapters; you screw them into the crank and screw your pedals into them.  Unfortunately, there's no way such devices can move your pedals outward just a little bit; it's gonna move them outward a lot.  Still, if this sounds like just what you need, check them out at:

Scor Productions
P.O. Box 2466
Fallbrook, CA 92028
Phone # (800) 548-4447
Fax #     (760) 728-0571

Toe Clip Length/Cleat Position

The ball of the foot needs to be located correctly on the pedal to apply force without tilting the pedal forward or backward.  With cleated shoes, this positioning is controlled by the location of the cleat on the bottom of the shoe.

Without a cleat on the shoe, this location is controlled by the length of the toe clip -- where the point of the shoe runs into the clip and won't go any farther.  This varies not only with the size of a rider's foot, but also with the configuration of the shoes he is wearing.  Hence, older design toe clips come in a variety of lengths.  Some later designs -- before clipless designs sent toe clips the way of the Dodo -- were adjustable length.

Note that the precise configuration of the toe clip is also important, besides just its length.  Some provide more room for a thicker shoe, while others will only allow a pointy shoe without crushing the toe.
 

Toe Clip Position/Cleat Alignment

It's important that the shoe is properly aligned on the pedal, toes pointed forward.  Riding slewfooted or pigeon-toed misaligns the knees; slewfooted can cause the heel to contact the chainstays.

With cleats, the way this alignment is adjusted is by rotating the cleat on the bottom of the shoe.  Some of the modern clipless pedals are deliberately designed to provide a bit of "slop" in this positioning, allowing the rider to twist his feet a little while riding.

Without cleats, the typical way of adjusting this alignment is by adjusting the toe clip side to side.  As the toe clip moves inward, so does the toe of the shoe, and the shoe is rotated inward.

It is convenient to adjust the toe clips or cleats while sitting on the floor next to the bicycle and inserting a shoe into the pedal.  As a final test it is important to take it for a test ride, but for the most part you can tell it's adjusted nearly correctly just looking at the shoe in the pedal.
  

Pedal/Cleat Wedges

The foot needs to be "level" on the pedal, with the outside edge of the foot being tilted neither downward nor upward. One would hope that the pedal, cleat, and shoe conspire to hold the foot properly level -- but don't count on it.  The foot being held with the outside edge tilted downward -- compounded with a flexible crank arm that allows the pedal to tilt even more downward under load -- is a prime cause of knee problems.  The downward tilt tends to cause the knees to move outward, and the stresses and misalignments that result cause ligament damage.

You need to make sure that your feet sit properly on the pedals.  The common way to accomplish an adjustment here is to insert a "wedge" between the cleat and the bottom of the shoe.  Such wedges can be purchased, but really it's almost easier just to make something.  Slip a layer of plastic from a milk jug in between the cleat and the shoe at the outer bolt only, or some such.

If the tilt you're trying to correct is caused by the crank flexing under load, it is highly recommended that you purchase a stiffer crank.  Using wedges is better than nothing, but really it's the wrong solution to the problem.  You'll end up with too much tilt the other way when pedalling gently, which will just cause its own problems.

The push for lighter components and better cornering clearance may also be contributors here.  Ideally, the body of the pedal should be directly under the center of the forward end of the foot, so you push down on the middle of it.  But the companies want to be able to claim their pedals are lighter and provide more cornering clearance, so they make the axles shorter and pull the body of the pedal closer to the crank.  Then the rider compensates by installing the cleat over towards the inside edge of the shoe.  The end result is that the foot is located the desired distance from the crank, but when pushing hard the foot isn't centered on the body of the pedal and tends to roll off.  If this is what's happening, the "Pedal Width" issue discussed above should be addressed with an eye towards getting the body of the pedal properly located under the foot.

Seat Height

This doesn't require a formula; it requires only a wrench.  Take a wrench along on a ride, and adjust until it feels right.  One bit of advice: in general, adjust it only about half as far as you think you need to adjust it.  Changes of 1/8" make a surprising difference.

If you are using a crank that is too short for you, setting the proper seat height tends to become a guessing game.  You can set it for nearly full extension at the bottom of the stroke, or you can set it a bit lower and it still seems to work just as well.  The problem here is that the crank is too short; if you fit a crank of the proper length, the correct seat height will become immediately apparent -- too high screws up your movement at the bottom of the stroke, too low causes too much bending at the top of the stroke.
 

Seat Fore/Aft Position

Read about the proper positioning of the seat under the discussion of seat tube angle above.  The adjustment fore and aft on the top of the seatpost is merely a fine tune adjustment of this position.

Many of the seatposts on the market don't hold the seat rails as firmly as one might hope -- notably, those with an aluminum alloy clamping arrangement working on steel seat rails.  Set it whereever you want, in the first few miles of riding it works itself to the full-rearward location anyway.  If you have this problem, you can solve it by dropping into a hardware store and buying a pair of cable/wire rope clamps.  These consist of a small clevis with a tiny U-bolt and two nuts.  Their intended purpose is for clamping two cables together, but for our purposes they should be installed as follows: position the seat where you want it, then assemble these clamps around each rail just forward of the seat post attachment.  Slide the cable clamps against the front of the seat post attachment and clamp them down tight on the rails.

The seat rails are typically 7mm, so offhand the 1/4" cable clamps would look like the best fit.  These are a little clunky, however.  You will probably be happier if you buy the 3/16" size and then open up the saddle portion of the clamp with a small round file or rotary grinder to fit the rails.  In fact, as long as you have that grinder in your hand, the saddle portion of the clamp can be majorly hacked and still work for this job; you can probably cut away half of it.  You might also consider cutting off the ends of the U-bolts, since they are too long for this application.  For some reason, the U-bolts from a 3/16" cable clamp are the perfect width to fit a 7mm rail.

Note that the seat carcass flexes with weight on it; you can push down on the top with your thumbs to see how it moves.  You need to take care to position the clamps so they don't rub the seat the wrong way.

If you get lucky, you can find stainless steel cable clamps; the basic steel ones will work fine, but they'll rust like crazy on your bike.
 

Seat Angle

In general, the seat needs to be nearly level.  The idea is that weight should be applied nearly vertically on it; if mounted either nose-down or nose-up, weight applied vertically would tend to cause sliding down it.  If you have a burning desire to tilt that seat one way or another, either there's another problem somewhere in your setup or you need a different seat.
 

Seat Type

To state the obvious: one guy's butt is not the same as another's.  Just because Lance Armstrong uses such-and-such type seat doesn't mean it'll feel comfortable under your fat can.  If you find a seat that works for you, stick with it.

Back in the old days, a racing bicycle seat was made of a solid strap of thick leather stretched between metal supports at the front and rear.  The front one had a screw adjustment for taking up slack as the leather stretched.  Such a seat could be broken in to fit a particular rider just as a baseball glove needs to be softened up and broken in before it's any good for catching fly balls.  The leather seat could also be modified fairly easily, such as by trimming a little leather off the edges or cutting a hole here and there.  Unfortunately, the leather doesn't take rainy weather well; there were many products available that purported to waterproof it, but all that water spinning off the rear tire would usually do it in.

The more modern seat design is a flexible plastic shell covered with cushioning and thin leather or vinyl.  The cushioning used to be foam, but lately it can be gel or some such.  Either way, a key part of this seat's operation is the flexibility of the shell; good ones have a really flexible shell while cheap ones use a hard shell.  You'll know the difference after a hundred miles.  Some of these type seats have interesting shapes; a slot in the center at the rear seems to be popular, although that area doesn't hit anything likely to be painful (unless you have hemmorroids) so it's not really a beneficial idea.  Better would be to provide recesses right where the points on the pelvis bone hit and fill those recesses with really thick cushioning.

One of the advantages of this later design seat is that you can often sit comfortably on it in several different positions: out on the nose, slid to the back, right in the middle, etc.  On the solid leather seats, there was only one place to sit, and comfortable as that may be it can get old after a few hours on it.  Being able to relocate every now and then is helpful.

I don't have to tell you that most of the better bicycle seats on the market were designed for the bony butts of the typical racer rather than for the wide posteriors of the rest of us.  As mentioned in the seat tube angle discussion above, the typical position of the racer puts a lot of weight on the hands and fairly little on the seat, while the more relaxed position of the casual rider puts more weight on the seat.  It isn't a good idea to make the seat wider, since that would interfere with pedalling motion.  Add to these problems the fact that the racer has built up a nice layer of callouses on his crotch while the rest of us are tenderfoots in that area and would generally prefer to stay that way.  All in all, finding a comfortable seat for the casual rider can be really tough.  One good idea would be to make the seat longer so you could sit on it without hitting the rigid portion on either end, but nobody seems to make such a seat.
 

Seat-to-Handlebar Distance -- Stem Length

See the discussion on top tube length above.  Whatever the top tube length of your frame, you supposedly can adjust the handlebar position to provide the optimum seat-to-handlebar distance by replacing the stem with one of a different length.  The length of a stem is measured horizontally (regardless of the actual configuration of the stem) from the axis of the steering tube forward to the centerline of the handlebar center.  Stems are typically available in lengths from 25mm to 140mm.  However, you would be well advised to try to select a frame with a suitable top tube length to permit the use of a stem in the 60-100mm range; shorter stems tend to handle funny, and longer stems tend to handle funny as well as flex too much under strain.

I have no formula to offer to provide guidance on determining what is the correct seat-to-handlebar distance for you.  The way I have always set it for others has been to ride alongside them and watched them -- if they appeared too stretched out over the bike, they needed a shorter stem; if they appeared all crunched up, they needed a longer stem.  I actually have a collection of stems of different lengths for people to try out, even though it is a PITA to change stems.  Some of my stems are kinda crummy, but once the proper length is determined the rider could order himself a nice one.  Nowadays it is possible to find an adjustable stem, but if your bike shop doesn't have one for you to try (or a machine for you to climb on to try different lengths) it probably wouldn't be worthwhile to buy such a critter; try to convince your local bike club to get one.

One bit of advice: if you decide you need to change stem lengths, change it by about half as much as you think you need to change it by.

Hogwash:  Some people advise setting the seat-to-handlebar distance by positioning the rider's elbow against the nose of the seat and positioning the handlebars so that the fingertips just barely contact the rear edge of the bar alongside the stem.  I'm sorry, but proper seat-to-handlebar dimensioning has nothing to do with the length of a cubit or the length of the nose of your seat.
 

Handlebar Width

The handlebar width is related to shoulder width.  I'd go so far as to suggest that it should be the same as shoulder width, but I'm not as sure of that.  I'm pretty sure that people with wider shoulders should have wider handlebars, though.  I think you'll be able to tell if your handlebars are the incorrect width during a hard sprint out of the saddle; they just won't feel right, and you may have trouble maintaining a straight line.
 

Handlebar Drop

Handlebar drop is the vertical distance from the centerline of the center clamp portion of the handlebar and the straight sections of the bar at the very end where you grip it when you're on the bottom.  A racer will typically choose a bar with the drop needed to put the lower grips where he needs them.  Since he also likes to use the smallest frame possible to save weight, he usually would like a minimum drop.  He doesn't care where the stem or bar center is, as long as it isn't in his way and doesn't weigh any more than it has to.

For others, it might be a good idea to select a slightly taller frame and a set of bars with more drop.  This would position the lower grips at the same place as before, but would position the upper grips higher making for a more relaxed ride when using them.

Bars with a bit more drop are available, but not by much.  The intention is apparently to use these for taller riders, so the difference between the upper and lower bars has a similar effect as the regular drop has for regular size riders.
 

Handlebar Bend

There are lots of subtle differences between handlebar bends.  Some will have a different radius horizontal bend between the center section and the upper side section just rearward of the brake levers, resulting in a different feel when riding on the upper bars as well as a difference in clearance against your lower arms when riding on the lower bars.  Some will have a simple radius between the upper side section and the lower grips while others will modify this radius to provide a better grip area within this turn.  Some will have the lower grip areas longer than others, which may allow you to slide your hands rearward for variety but may also get in your way when standing and sprinting; of course, you can simply saw them off if they're too long.  Some will have longer horizontal side sections, locating the forward bend and the lower grip areas farther forward.  Some will have slightly larger diameter tubing than others.  Some will even appear identical but will have different flex characteristics, resulting in a considerably different feel when riding or sprinting.

Some variations are not so subtle.  One is designing the center section to bend upwards at the outer ends rather than being a straight tube section.  This effectively raises all the grip areas of the bar, providing a similar change to installing a taller stem or a taller frame size.  It can also provide a slightly different feel when riding on the upper bars, a feel that some cyclists like.

Another difference is the angle of the side portions of the bar.  Most bars are nearly vertical here, but some slope outwards.  With the same width spec -- which is measured at the lower grips -- this means that the horizontal bend is moved inward, which affects the position of the hands on the upper bars.  The brake grips also tilt with the angle of the forward bend.

Another difference is in the angle of the lower grips relative to the centerline of the bike.  Most are parallel, but it is possible to get bars that angle outward somewhat -- and it is possible to mount bars with parallel grips in a vice and bend them outward a bit!  This provides a grip angle that some riders prefer.
 

Handlebar Angle

All it takes to change this is a wrench: loosen the clamp bolt on the stem and turn the bar until the lower grips sit at the correct angle for you.  It's pretty easy to know what is the correct angle; it's the angle that makes your wrists most comfortable.  Usually you can loosen the bolt, sit on the bike, put your hands in position on the lower grips and just turn the bar to the right position and tighten down the bolt.

Hogwash:  Some advise that the lower grip should be parallel to the ground.  These people must never have ridden a bike, because this is miserably uncomfortable.  The correct position is usually with the ends of the bar pointing at the vicinity of the rear axle.
 

Clip-Ons

The term used to describe the many versions of additional handlebars and grips used to provide alternative riding positions, usually for better aerodynamics during time trials.  Some designs allow several variations and adjustments, while others are a fixed configuration.  Note that, in general, getting your elbows close together in such a position provides better aerodynamics while having them farther apart is more comfortable, so being able to adjust the width of the armrests may be useful for the rider getting used to them.

It must be said that riders who have installed clip-ons generally recommend them highly, even when not time trialling or competing.  Set up properly, they provide a genuinely comfortable riding position, usable when just cruising around.  Their only disadvantage is on bumpy roads, where the shocks are transmitted directly into your elbows rather than absorbed by the flex of your arms -- but on bumpy roads you can simply switch back to the grips on the conventional bars.
 

Handlebar Tape

There are a great many products used to provide grip on handlebars.  Racers traditionally choose a simple cotton fabric tape, lightweight, durable, and provides good grip even when wet.  Cheap bikes sometimes come with a thin plastic tape which tears easily and is totally worthless when wet, arguably even dangerous.

Other options include a type of thick, gushy plastic; it provides good grip and some cushioning when dry, but can be slippery when wet.  Sometimes it's provided with tiny holes or a surface texture, either of which can cure its wet slipperiness.  Cork is also a popular material, lightweight, good grip wet or dry, and providing a bit of cushion; unfortunately, it tears very easily, the first time you lean the bike up against a brick wall it'll be torn.  Hence, many companies offer tape that either consists of cork bonded to a tougher under layer or a "cork composite" -- cork mixed with some man-made material to give it toughness.

Cushioning here may sound like a great idea, the more the better, but allow me to explain what a mistake this can be.  There is (or was -- I haven't seen it lately) a product called Grab-Ons, four pieces of tubular foam that were slid onto the bar from the end.  They provided a layer of foam all around the bar that was perhaps 1/4" thick.  At first, this strikes a rider as quite comfortable, and in very gentle straight-line cruising it can actually be pretty nice.  However, this much cushioning runs into a problem with a feature of the human anatomy known as the "grip reflex".  Basically, when the brain tells the hand to hold onto something and don't let go, the hand has a grip reflex that automatically adjusts the tightness of the grip as it senses that the item being held might be slipping.  This reflex is automatic to the point where most of us don't even realize it is operating; as far as we know, we're just consciously gripping an item, no reflex involved.  However, when riding a bike with the level of cushion provided by Grab-Ons, especially where control is necessary such as maneuvering or sprinting, the hand senses the bar moving around within the foam and interprets that as slipping -- and the hand grips progressively harder.  The result is that after comparitively short rides, you may find your lower arms cramping up and not even understand why.

From my personal experience, the best handlebar covering is genuine leather.  Racers don't like it because it weighs too much, but for the rest of us it is just great.  Sometimes you can find leather handlebar tape, but if you can't it's easy enough to come up with some: just visit a local auto parts store and buy a genuine leather steering wheel cover (don't get any cheap imitation stuff!).  Pull the stitching out of it, which will leave you with a single strip about two inches wide and 47 inches long.  Cut the strip lengthwise, which will leave you with two strips -- one for each side of your handlebars.  Use a piece of tape to hold the end to the bar while you begin wrapping, being sure to cover that tape with the first wrap.  Your biggest problem will probably be finding a plug that works well at the bar end, since some plugs don't work with tape this thick; a simple metal push-in plug seems to work better than the more elaborate designs.  This stuff will last for years; you can unwrap it and rewrap it when replacing brake grips or bars.

You can also get creative and use that steering wheel cover more in line with the way it was intended.  By cutting it into two equal-length pieces and then making a suitable cutout for the brake levers, it's possible to lace it onto the bar.

Note that the rider's decision to wear cycling gloves figures into the choice of handlebar covering.  He may decide to forgo the heavy leather wrap and use lightweight cotton tape instead, and wear leather gloves for comfort.  This way, he can proudly claim that his bike is lightweight!
 

Brake Grips

There are at least two factors to consider when selecting brake grips.  The first is the reach: how far your fingers must spread to get around them.  If you have big hands, you won't have trouble with any grips, but if you have small hands you may have trouble reaching some grips.  Note that some brake grips have adjustable reach.  Also note that the bend of the handlebar they are mounted on makes a difference.

The other concern is with the leverage, or how far the cable moves with a particular amount of grip movement.  If the cable moves a lot with grip movement, the brakes themselves can be adjusted quite a ways away from the rims and still provide good stopping power by the time the grips are pulled back to the bar.  However, there is poor leverage this way, so it requires a strong hand to pull them.  If the cable moves a shorter distance with grip movement, the leverage is better and it doesn't require as much strength -- but you can't get much brake motion, so the brakes must be adjusted very close to the rims to provide good stoppage, and therefore the rims must be kept perfectly straight to avoid rubbing.  In many cases they will rub as the wheel flexes when riding.

Taken together, it becomes apparent that a person with small, weak hands can have serious problems stopping.  One hopes he is also lighter so there isn't much mass to stop.
 

Brake Arrangement Left/Right

Most bikes are set up with the front brake grip on the left and the rear brake grip on the right.  The Italians have to be different, and put them the other way around.  Motorcycles are another concern, having the front brake grip on the right, the rear on a pedal, and the clutch on the left.

It's not a petty concern; proper braking control requires coordination, which in turn requires practice.  An experienced cyclist, trying to stop as quickly as possible, will modulate the front brake very carefully to stop quickly without lifting the rear wheel off the road -- and won't touch the rear brake.  Motorcyclists have similar concerns, even though it's not as easy for them to lift a rear wheel, so they usually can apply some rear braking when stopping hard.  The point is, once you're used to applying that front brake skillfully with the left hand, it is really difficult to relearn it with the right hand -- and making the switchover can be dangerous in a panic stop.  It doesn't really matter which way you set the bike up, but you're gonna want to stay that way, so choose carefully.  If you also ride motorcycles, you might want the front brake on the right.  If you compete in events where you may be provided a loaner bike if yours breaks, you may choose to make sure your brakes are set up the same way as the loaner bikes.
 

Brake Pads

As mentioned above, the front brakes only should be used for any hard braking; the rear will just slide, since there will be no weight on it.  Rear brakes are good for limiting downhill speeds, but in general riders should avoid the habit of using them at all.  As a help for control, it can be a good idea to install different type pads on the two ends of the bike.  On the front, you want the best gripping pads you can find.  On the rear, you'd like pads with minimal stopping power, preferably with good heat resistance for that downhill application.  Good luck finding pads designed for minimal stopping power; usually the best things to install are old pads that have been in the sun too long and are all dried out and hard as a rock.
 

Shifter Location

The shifters for your derailleurs can be located several different places: on the sides of the down tube, up on the stem, on a thumb lever near the brake levers, on the tips of the handlebars, built into the brake levers themselves, or up on the nose of a clip-on handlebar.  Gee, did I forget any?

The downtube location results in the shortest cables and therefore the least weight; they are quite convenient for shorter riders, but they can be quite a reach for a taller rider.  The ones on the stem are convenient, but they are subject to being hit with a knee during an out-of-the-saddle sprint, which can be very dangerous.  They also can be dangerous in a crash due to their location.  The bar-end type shifter is convenient since it can be shifted with a little finger without even removing the hand from the bar, but again are subject to being kneed in a sprint.  Most riders that use these type shifters like to saw off the ends of the bar to bring the shifters up close to where their hands actually sit.
 

Number of Speeds

The more the better, right?  Actually, no; there are disadvantages to providing more speeds, and you should be aware of them rather than just buying the components that provide the most available speeds.  First off, there is the issue of rear wheel dishing.  A spoked wheel is strongest when it is symmetrical, the spokes on one side are arranged at the same angle as the other.  To fit a multi-speed freewheel on the right side of the rear wheel, however, the wheel is "dished" -- the spokes on the right side are arranged in a pattern that is much "flatter" than the opposing side.  This weakens the wheel considerably.  It would actually be better if the left side was brought in, making it as flat as the right side, but nobody seems to offer hubs designed to do this.

If you are competing in stage races or other events where you may be given a loaner wheel in the event of a puncture, you need to set up your wheel to have the same kind of dish -- and the same kind of freewheel -- as everyone else's so that you can use a loaner wheel with no problem.  If that isn't a concern, however, you might consider other arrangements -- especially if you are a big, heavy rider.  The smaller guys might get away with any wheel configurations, but larger guys might find fewer broken spokes and less wheel flex a worthwhile objective.  If the hardware permits it -- and it usually does, although it may take some fiddling -- you might choose to remove one of the rear cogs and respace the entire hub over to the right, allowing less dishing and a much stronger wheel assembly.  Of course, if you use a disk wheel or a composite wheel where dishing isn't an issue, none of this is worthwhile.

Many of the products on the market provide an extra speed or two in the same space by using narrower parts -- narrower sprockets and/or narrower chains.  Usually, such changes will result in weaker parts -- faster sprocket wear rates, more broken chains, etc.  In some cases the manufacturers upgrade the quality of the components to minimize these effects, but you will pay for the difference -- not just the first time, but each time you buy replacement chains and cogs.  Again, if you are a large rider that puts a lot of stress on parts, you may choose to forgo the extra speeds in favor of more durable or more reasonably priced parts.

Tourers and others who need lower gears for hillclimbing will often opt for a "triple", a crankset that will hold a third chainring inside of the main two.  It usually uses a completely different set of mounting bolts with a smaller circle, permitting the use of a much smaller chainring.  A simple mathematical calculation shows that even a moderate grade requires a seriously low gear ratio to climb at a relaxed pace, as opposed to the racers that pound up hills in relatively tall gears.  Having 80 pounds of gear strapped onto the bike just adds to the need for lower gears.  If you don't have a triple crankset but prefer to keep your road crankset, it's possible to install small inner chainrings on a road crankset via use of an adapter chainring in the middle position.  See my patent at The U.S. Patent and Trademark Office.

Here in Florida where it's flat, some of us remove the front derailleur and inner chainring altogether.  It never gets used anyway, so it's just unnecessary weight and complexity.  Not having a front derailleur makes shifting simpler, since you don't have to fiddle with the clearance on the front derailleur each time you shift the rear cog.
 

Gear Ranges

You're not stuck with the ratios that come with the bike.  Typically, an off-the-shelf bike will come with 40/53 front chainrings and rear cogs with a 13-to-24 range.  This is a good all-around setup, but for your particular uses you might want to change it.  Racers will often toss that 13-to-24 set in favor of cogs one tooth apart -- 13-14-15-16-17-18, or the like.  They also may install a 12 or even an 11, giving a taller top gear, although there are fundamental mechanical shortcomings of very small sprockets; a better idea would be to replace the 53T chainring with a 56T, but almost nobody chooses this route.

Tourers may choose to go the other way, and install  rear cogs with a lowest gear in the 30's somewhere.

When you change freewheels this way, note that you may need to replace your rear derailleur at the same time -- and you may want to even if you don't need to.  As the derailleur moves from the small cogs to the bigger cogs, it needs to hold the upper jockey wheel close to the cogs to provide sharp, crisp shifts.  If the derailleur is designed to hold close to the 13-to-24 freewheel, switching to a 13-to-18 freewheel will result in the jockey wheel not being anywhere near that 18, so shifting response at this end of the cluster is likely to be poor indeed.  Conversely, going to a 13-to-32 freewheel will likely result in the upper jockey wheel jammed into the gears; the derailleur will often have to be replaced.  Derailleurs are normally described as having a "max cog" limit, and for best shifting it's usually best to select a unit with a limit minimally capable of operating on the size cogs you will be using.

Another concern is total chain tensioning capability of the rear derailleur.  The lower jockey wheel is on an arm sticking out the bottom, and in general the length of that arm determines how much slack the thing can take up.  Note that it must take up the slack caused by different cog sizes on both ends of the drivetrain; the front derailleur won't be taking up any slack.  The capability of a rear derailleur to take up chain slack is normally described as the "capacity", a number of teeth.  For the derailleur to work, it must have a capacity as great or greater than the difference between the largest chainring plus the largest rear cog minus the smallest chainring plus the smallest rear cog.  For example, the 13-to-24 freewheel with the 40/53 arrangement will require a (53+24)-(40+13) = 24T capacity.  Again, it's usually best to select a derailleur with minimally adequate capacity, since a longer arm holding that lower jockey wheel not only adds weight (including a longer chain) but it seems to allow more chain whip.

Note that there are rear derailleurs that address the problems of changing freewheel sizes and capacity by mounting the upper jockey wheel on a lever as well (instead of a fixed location on the derailleur parallelogram) and/or a spring in the pivot joint of the derailleur hanger itself.  When these things work they work very well indeed, but they seem to be a little difficult to set up correctly.

Wouldn't it be nice if the off-the-shelf bikes came with gearing appropriate to the area they were being sold in?  Here in Florida, bikes could come fitted with close ratio freewheels and the derailleurs to shift them properly, while in the Rockies bikes could be fitted with hillclimbing ratios and the derailleurs that work with them.  Ah, well, too much to ask, I suppose.  At least you now know how to special-order exactly what you need for the type riding you will be doing.
 

Tires/Wheels

The first decision for the road bike rider is tubular vs. clincher.  Tubulars, also known as sew-ups, have the tire and tube built into a single assembly, and the entire thing is glued onto the slightly concave outer surface of the rim.  This design was originally conceived for use with solid wooden rims, but with hollow metal rims it provides a very lightweight assembly.  The gluing job needs to be really good, lest the tire will "roll" -- either coming straight off the rim, or turning inside out while staying on the rim.  The arrangement also provides some resistance to impact damage, since the tire will be pinched against a relatively smooth and broad wheel surface.  Some tourers prefer tubulars because a spare -- tire with tube built in -- can be folded up and tucked in a pocket.  Finally, since this type tire is the traditional preference of racers, there is an outstanding selection of really top-quality tires and rims to choose from.

Clinchers, also known as wired-ons, are generally preferred by casual riders.  The tire and tube are separate parts, and the tube is inserted into the tire as the tire is pried onto the rim.  The rim has to have flanges on the edges to grip the beads of the tire, and the tire must have wires or cables in the bead to hold it in the flanges on the rim.  The wires in the tire and the flanges on the rim mean that clinchers will inherently have more weight than a sew-up arrangement.  Clinchers are notorious for puncturing tubes when hitting bumps in the road; the edge of that flange on the rim will pinch the tube between the sidewall and the tread of the tire in a local spot, cutting a neat little hole.  Often it'll do it on both sides, leaving a "snakebite".  Some tourers prefer clinchers because they can carry a spare tube easily and they can buy a replacement tire just about anywhere, including local department stores.  There are also tires available with Kevlar cables in the bead instead of metal, which not only makes them lighter but also makes them foldable so a spare can be stored on board.  Finally, excellent tires and tubes are available and typically for less money than comparable tubulars.

In the old days, clinchers were available in either 27" or 700C sizes.  27" is actually about 1/4" larger in diameter than 700C, even though 700C tires were referred to as 28" for a while in the U.S.  Today, 700C has basically won out over 27", and this has very important benefits for us all.  First, 700C is the same diameter as the tubulars, so you can keep sets of both types of wheels and swap them out as the urge strikes you.  Second, while framemakers used to have to design frames to accommodate both sizes of wheels, they now are typically made to hold 700C's only, allowing for closer fit brakes and the like.  Today, there is simply no excuse for choosing 27" wheel size.

Once you choose clinchers or tubulars, you need to choose the width.  The basic 27" clincher was described as a 1-1/4" cross sectional width, and the equivalent 700C's were described as 32mm.  Then they started to make them narrower, introducing the 1-1/8" and 28mm followed by the 1" and 25mm.  Today you can get 20mm tires.  Any 700C tire will fit on pretty much any 700C rim and the same is true for 27" tires and rims, but in general it's a good idea to use narrow tires on narrow rims and wide tires on wide rims.  There are similar width choices in tubular tires, although most of them tend to be narrow.

For speed, the narrower tires are better -- even for cornering, which may seem counterintuitive.  The wider tires are helpful on bumpy roads, dirt roads, or for very heavy riders.  They will provide a softer ride, if that's important to you.

In clinchers, you can choose between "skinsides", "gumwalls", or "blackwalls".  Skinsides have sidewalls that appear to be nothing but fabric, and paper-thin fabric at that.  The gumwalls have rubber sidewalls, sort of tan color; it's really a layer of rubber applied over the same fabric that's uncovered in the skinsides.  Blackwalls have rubber wrapped all the way around the tire carcass.  The gumwalls and blackwalls have better damage resistance; it's pretty easy to cut a skinside sidewall if you hit something in the road.  The skinsides roll better, weigh less, handle better, go faster.

You can also get tires with Kevlar fabric in the carcass, making them very puncture resistant; Kevlar is what bulletproof vests are made of. You can also get strips to insert into a normal clincher between the tire and tube for puncture resistance.

With tubes -- either clincher or built into the tubulars -- you can get basic butyl, thin butyl, butyl/latex combo or pure latex.  Butyl is cheap, black.  Latex is tan colored, translucent, has better puncture resistance, but it loses air at a faster rate: you'll need to pump up butyl tubes a coupla times a month, but you'll need to pump up latex tubes every day.  For some reason the latex tubes can be made thinner, so they weigh less.  You can also get butyl tubes that are extremely thick, like 1/4" thick, as a puncture-resistance feature; this idea seems better at separating the customer from his money than at preventing flats, however.


Whew!  And you thought all you needed to do was order the right frame size!  I've probably forgotten a couple of things, but I'll add them as I think of them.  Maybe someday I'll even add some graphics!

Happy cycling!