An admitted shoe geek waxes philosophical about running, triathlon, and life in general.
Comments welcome!

Saturday, March 5, 2011

Bike Fit

I'm one of those people, probably very irritating, that has a rote answer when people ask which bike they should buy.

"The one that fits."

Standing and straddling the bike's top tube may have worked when you were 5 years old, but there's a whole lot more to "fit" than that. And I cringe every time I see some one in a bike shop standing over a bike and saying, "See, it fits." What if you have longer legs than average for your height? Or shorter? What if you have shoulder or neck issues that prevent you from contorting into a racing position? What about your natural level of flexibility?

Different brands, and even different models within that brand, will fit differently. Some are made specifically to deal with the long- or short-of-leg people. Women's models may have even more accommodations to smaller proportions (brake levers, handlebars, etc).

Sure, you can most often make any road bike support you at your preferred contact points (meaning the saddle, handlebars, and pedals). But that doesn't mean the bike fits. A super long stem may put the handlebars at the right place for your hands to fall on them naturally and with little effort, but that may also put much more of your weight on the front wheel, leading to handling issues and loss of traction at the rear wheel.

With tri bikes, it becomes even more important. I was around tri before tri bikes even existed. All our road bikes were tri bikes. Because it's all we had. And we did some pretty messed-up things with those bikes, all in the name of decreasing aerodynamic drag. Never mind that the bikes then grew minds of their own when it came to handling them in windy conditions, or technical courses. Again, I cringe when I hear people say they can convert their road bike into a tri bike by adding a long stem and a forward-facing seatpost. I remember those days, and no way do I want to go back.

Now I'm not saying that you need to go out and spend $350 on a professional bike fit (though often the shop that does this will apply a certain amount to the purchase of a bike), especially if you've been riding a long time and already know what's comfortable for you. I've bought several bikes that I'd overlaid onto my current position (using CAD software in 2D mode) to know whether it would fit. Likewise, I've eliminated many from consideration by doing the same thing.

But what if you're new to riding and don't already have a dialed-in position? Then, at the very least, have a knowledgeable person help you set up the bike. Or go to and use their fit calculator (uses a lot of body measurements). It will only be an approximation, and the position will evolve over time. This is what I did over a 10 year span (because there WERE no professional bike fitters then) -- I used the standard ball-park "fit" that the bike shop gave me, did a bunch of reading, made adjustments (different handlebars, different stems, different saddles), evaluated, adjusted... It was a long and, if I were to add it up over the years, faily expensive process. But once I settle on my position, it's been comfy ever since.

And one more VERY important point -- if you're new to riding, don't expect the bike to be Barc-o-Lounger comfy! Your body needs to adapt as well. Give it time. Make small adjustments, and you'll settle in on a comfortable position.

While on a lunch time ride with a co-worker the other day, we got to talking about "riding season" and saddle soreness. He said that he knew he hadn't been riding as much because he was getting a little sore. I said maybe I've just been doing this so long that I have permanent calluses on my ass, but I haven't had saddle sores in probably 15 years. He quipped, "Maybe it's just nerve damage."

But that speaks to something -- if you do something infrequently, you put your body into "new" mode every time you do it. Meaning if you ride infrequently, you're probably going to have saddle sores after almost every ride. Your body is a constantly adapting unit. And if you eliminate the stimulus that your body adapts to (meaning the riding), your body will "un-adapt" to those stresses. The use-it-or-lose-it principle.

So until you've figured out which bikes will fit you, don't ask me which one you should buy, because now you know what you'll get in reply.

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