OVERVIEW Bike fitting is endlessly discussed among cyclists and for good reason. It can really make or break your cycling experience. I cannot add much of value to the volumes that have been written on the subject. Still, I can mention 4 points that have been helpful to me: Understand that there are very different styles of fit, each suited for different purposes and riding styles. Use a well tested formula-based system to determine your frame size according to a variety of measurements of your body. Customize your fit by swapping out components. This is a life long process. Seek expert fitting advice from a local bike shop, but take it with a grain of salt.

MENU DAVE'S NORDIC BACKCOUNTRY SKIING PAGE DAVE'S SPORT TOURING CYCLING PAGE THE 3 STYLES OF BIKE FIT FORMULA BASED FRAME PURCHASING ADJUSTING FIT WITH COMPONENTS SEEK LOCAL EXPERT ADVICE

They call the second fit style the Merckx fit after the famous Belgian racer. This puts the bars 1" to 2" below the saddle. Before you dismiss this fit style as somehow less efficient than the Competitive Fit, you should know that some believe that this type of fit is ultimately more efficient since it puts the rider in a more comfortable position where he or she can breath better. These somebodies include Eddy Merckx and Lance Armstrong. According to one article, Lance arrived at this more moderate body position after extensive wind tunnel and power testing. The conclusion was that any aerodynamic benefits of the low bar style were undercut by decreases in the ability to breath, and with that, a decrease in power output.

The final fit style is called the French style in reference to the classic french style touring bikes. This style puts the bars at about saddle height and is generally associated with long distance riding. It is common for cyclists to migrate to this fitting style as they age. But, I would caution against dismissing this as the style for older riders only. If your goals are long distance cycling such as touring, brevets, centuries and other "event" rides, then this fit style should be considered closely.

My only strong opinion on these styles is that the low bar competitive fit should be avoided by pretty much everybody - or at least by anybody who will be reading this web page seeking fit advice (as opposed to a racing oriented site). Some young racers will always choose to punish themselves, but the rest of us mortals should probably have our bars 0" to 2" below the saddle. I flatly reject the argument that if the competitive fit works for pro cyclists on long road races, then it should work for us. Firstly, few recreational cyclists have the time to put in the amount of training needed to force your neck and shoulders to take that position and fewer still have the pain tolerance of pro racers. Secondly, there is good evidence to suggest that it's a misguided approach to gaining efficiency. My advice is to honestly assess your riding style and then choose between a Merckx or French style of fit.

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In terms of the frame, fit is primarily determined by the length of the seat tube and the length of the top tube. This is complicated a bit now that top tubes are no longer flat. So, for comparisons sake, many manufacturers will publish the "effective seat tube" and "effective top tube" lengths, which are the lengths the tubes would be if the top tube where level.

Traditionally the seat tube length was chosen according to the rider's inseam or height. On traditional frames, this was considered to be the "size" of the frame. Today, some argue that top tube length should be the determining factor when selecting a frame size, since long modern seat posts give us the ability to make much larger adjustments in saddle height. Different manufacturers use different proportions between these tubes and these differences can be seen in the frame geometry information that is generally published. Related, different fitting styles and different intended uses will make a longer or shorter top tube more appropriate. For example, a low bar road racing bike will generally have a longer top tube than a high bar touring bike.

Be especially cautious about buying a bike frame that is too small for you or that will force to accept a low-bar fitting style. As a rule, I suggest that the bike should permit the bars to be set at a position that is level with the saddle. On modern bikes with threadless headsets, this may mean the use of an uncut fork with a large number of spacers to get the bars up high enough. It is better to leave the shop with a fork steerer tube that is long (and that can be cut down to a shorter length if you really feel the need) than it is to leave with fork steerer that is racer-boy short. Threadless headsets offer fewer possibilities to adjust handlebar height than 1" threaded headsets do. In particular, with threadless headsets, you are limited to using stems with different angles to make fairly minor changes in handlebar height. But on 1" threaded headsets, you can use stems like the Nitto Technomic to raise the bars by several inches. At some point, the only way to raise bars on a modern threadless headset is to replace the fork, which is both expensive and may introduce significant changes to the handling and performance of the bike.

Having noted that 1" threaded steerers offer more adjustability, I should caution against thinking that this makes them better. In general, if you need to use a super high rise stem like the Technomic, this suggests that you frame may be too small in other respects. Putting it another way... if you have to dramatically raise the bars on your bike, whether it is by replacing the fork on a threadless steerer bike or by using a Technomic stem on a threaded steerer, then it is likely that your frame is too small. In either case, it would have been better to get a better fitting frame to begin with.

So, let the fit guidance from Competitive Cyclist direct you and narrow your bike search by eliminating bikes that differ significantly from their recommendations. Pay attention to the recommened (effective) top tube length and seat tube length and read the geometry information provided by the manufacturers carefully to eliminate ill fitting models. Then test ride the top candidates and verify that the shop can get the bars up high enough before you purchase the bike. Remember, all you need to do is to avoid getting a grossly ill-fitting frame. As long as you are close, you should be able to fine tune your fit with component changes.

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There are countless articles on how adjust and fine tune your fit available on the internet. By far, one of the best articles I've read on adjusting your fit is by Peter White at his website. The thing I appreciate most about Peter White's approach is he recognizes how fit is affected by things such as the rider's style, preference and age.

The components that have an affect on fit include the seat post, the handlebar stem, the handlebars and the crankset. The most first and most obvious adjustment to be made is the height of the saddle, which is adjusted by the seat post. However, just as important is the fore/aft position of the saddle on the seat post. The position of your hips relative to the center of your cranks forms the foundation of your bike fit, so together, these 2 adjustment are absolutely critical. In nearly all cases, the seat post that comes with your bike will provide you with the range you need to get a proper fit. Typically the only reason people replace their seat posts is to achieve some fashion oriented goal such as weight reduction or looks. However, occasionally a person needs to move their saddle more foreword or, more typically, more rearward than their stock seat post will allow. To achieve this, you can use special "set-back" seat posts.

Not long after the saddle height has been set with the seat post, many cyclists conclude that the stock saddle that came with the bike needs to be replaced. For most long distance cyclists, this is a correct conclusion. Most modern saddles consist of plastic shells that are covered with some sort of foam material and then wrapped in leather or some synthetic material. Another style that has re-emerged is the unpadded shell. I first saw (and used) unpadded plastic shell saddles in the 1970s and today they've reappeared made from super light carbon fiber. Lastly, and in my opinion most importantly, there is the leather saddle; namely the Brooks line of saddles. While I'm generally trying to steer clear of offering specific fit and comfort advice on this page, I will say that the Brooks B-17 has been, far and away, the most comfortable saddle I've ever used. But saddles, like ski boots, are a very personal issue. Different back sides demand different saddles. As a rule, the wider your sit bones are from each other, the wider saddle you'll need. Related, the higher your cadence is (the rate at which you spin the pedals), the narrower saddle you'll prefer.

Another of the most frequently changed piece is, or should be, the handlebar stem, which adjusts both your reach to the bars and the height of your bars. The height of the bars relative to your saddle height should be determined by your riding style (not by the well meaning suggestions of racer wanna-bes). The standard rule of thumb for determining the reach from your saddle to the bars is is that this distance should equal the distance from your elbow to the tip of your middle finger, which is a very easy test to perform. That said, finding the best reach and handlebar height can be a life-long quest. For this reason, it is not uncommon for experienced cyclists to end up with a small collection of stems in their parts bin. Worse, this can change over time. The more you ride, the more your neck and shoulder can accommodate lower bars but the more you age, the more you will like your bars up higher. Some better bike shops even have adjustable stems that they can loan to customers so they can try various combinations before buying. If your shop offers this service, take advantage of it.

The handlebar is another commonly replaced part. Bars can vary in terms of their width and in the distance from the top of the bars to the bottom of the drops. And, there is a nearly infinite number of variations in the different curves and shapes that are available. Each bar style has its devoted fans and its not uncommon for cyclists to try many different styles before finding comfort. Generally speaking, bar width is related to the rider's shoulder width, but there is plenty of room for variations here.

The last component that can be adjusted to affect fit is the crank set. The length of the crank is the most commonly discussed variation. One school of thought says that crank length should vary based on femur length and concludes that tall riders should be on very long cranks and short riders on short cranks. Another school of thought is that crank length should be adjusted according to riding style. According to this line of thinking, low cadence power riders should use longer cranks and high cadence spinners should use shorter cranks. And yet another school of though says that for many decades everybody rode on 170mm cranks and got along OK. Each of these perspectives has a kernel of truth in them.

The other aspect in which cranks can vary is called the tread, which is the width of the cranks measured from the outside face to outside face at the pedal threads. In some circles, this is called the Q-factor, or quack-factor, as in how much the crank makes you ride like a duck. Some folks argue that narrower is better. Others suggest that the tread should match your hip width. And others suggest that the angle created by your knees should dictate the ideal tread for the rider. Most agree that tread can have an affect on knee pain. Whether you're concerned about crank length or the tread, I think the reality is that most folks just ride with the stock crank that came on their bike. Quality cranks are expensive items to replace.

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Copyright 2006 by David Mann