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  Last updated: 6/21/2016

Bicycle Sizing

Are you are investigating options to tweak your bike - new stem, seat adjustment - to make it more comfortable? Are you considering a new bike? Or maybe just planning on a bike trip and need to order a rental bike.

I. Sizing for a rental bike (prompted by a question from a friend). The following 2 links answer the question.

II. The science of bike fitting. The following are a few other links you may find of interest.

The Colorado Cyclist website has been around for years, and they specialize in fitting your new bike on-line.

As women often have unique sizing questions and problems, the Terry Bicycle webpage (a company that touts itself as specializing in women's frames) offers their ideas on frame geometry.

Here are some additional of interest.

III. Reprints from 2 interesting articles.

IV. Frame building techniques. This detailed critique on frame building will give those interested even deeper insight into how all those measurements come together and translate into bike performance.

Now for a few questions whose answers may help reinforce these ideas.

Q. I am a new rider and still in the Hybrid ranks with my 1989 Schwinn Crisscross. I recently did a two day 150 mile charity ride (second year on the same bike) and felt pretty good. I did ride extensively and did light weight training, spin classes during the week, weekend rides - anywhere from 20 - 40 miles on Saturday and Sunday. I maintained this regime for about 3.5 months prior to the ride. So I would consider myself in pretty good shape.

My question is the riders I rode with in the ride were in marginal shape - however they both had brand new road bikes. One had the Lemond -Alp Duez and the other had a FELT. Prior to the ride I found I was working doubly hard to keep the pace when we went out on training rides. In fact on one ride I hung with a group of 7 with road bikes for about 30 miles and I seemed to be the only one sweating. I weigh 210 and the other riders were about the same weight. However they finished a good 40 minutes ahead of me. My bike weighs approximately 25 lbs. - can the bike make that much difference in the ride? I am feeling a little blue today because I thought I was going to do much better. - TZ

A. Weight does make a difference, especially in the pedals and wheels as you are continuously accelerating and decelerating as you ride and the inertial resistance to acceleration is a big energy drain. And the geometry, rather than the weight, of the frame is a large factor as well. It is not the 5 pounds in the frame itself (which could easily be in two water bottles instead).

Q. I usually do road rides of 50 miles with 3M to 4M feet of elevation and I wear Sidi Bullet, (@ 650 grams), which are mountain bike shoes. Climbing is my weakness. Would I see any improved performance if I started wearing lighter and stiffer road bike shoes, such as the Sidi Genius 5.5 HT Carbon, (@ 540 grams)? NT

A. The weight in pedals, cranks, chain, and rims/tires (which has angular inertia when you are accelerating - something you are doing all the time even when on the flats) is much more important weight than in the frame, your water bottle, etc. The decrease in weight of these shoes might make some difference in climbing. But the stiffness or other design features would not. I once had a fellow at a local bike shop tell me that all he did was buy lighter rims - he biked a lot - and yet it allowed him to ride another 10 miles before he got to his usual level of fatigue.

Questions on content or suggestions to improve this page are appreciated.

Cycling Performance Tips
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