How to fit a bike

Now that you are ready to buy your on-line bike, how will you know what size to buy. Please note that this information also applies to buying in a bike shop. The more you know about bike fit, the better consumer you will be.

What many cyclists don’t understand is that there is a difference between bike size and bike fit, and even a bike that is the right size might not be set up to fit your body well. What’s more, even the most experienced cyclists might not be able to tell right away whether a bike fits properly. But bike fitting is not some magical black art that only a few master. With some help you can get yourself in the ballpark and then experience will perfect your setup.

A bike is the right size if it can be adjusted to fit you properly. And the key in here is that it must/can be adjusted. Getting the right fit usually requires small adjustments to the seat height, saddle fore-aft position, handlebar position, and maybe even the cleat position on your bike shoes, if you use clipless pedals (although float cleats tend to minimize the need for exact positioning). It may also require swapping out your seat post, handlebar stem, or crank arms for longer or shorter ones. You do not need to a Masters Degree in Biomechanics to get your bike fit, just a little patience and maybe the help of someone dear to you (more later*).

The old way:

1. Throw you leg over the top tube.
2. Is there about an inch of clearance?
   • Yes: It fit’s
   • No: Try another size

The new way:

1. Perform the required measurements (*with the help of someone dear)
2. Use one of the many on-line calculators
3. Print out the results
   • Take the results to your bike shop or view specifications online
     • Yeah, a bike that is the right size!

Now what? Notice I said, right size and not a bike that fits. Here is where experience come in. It also takes some riding to "dial-in" the precise fit for your new bicycle and old body. You are in the ballpark with the on-line calculators but to get precise minor adjustments still need to be made. If you are not comfortable with making these adjustments then by all means take yourself and your new bike to a local bike shop that does bike fittings and pay them to do a thorough fit. Don’t forget to bring your cycling clothing and shoes too. For just a little scratch you will ride away with a bicycle that will provide many miles of pain-free riding. 

If you want to do it yourself, then be prepared for a lot of riding. Make small adjustments to saddle height if you are suffering from pain either in the front or back of the knee. If you are constantly sliding forward or backward on the saddle then either adjust the saddle fore/aft position. If you feel too stretched out then look at a shorter stem or flip it over to get just a little more rise out of it. If your lower back hurts, then do some core exercises to strengthen your abdominal muscles.

On-line bike fit calculators:

Competative Cyclist Fit Calculator

Wrench Science Fit System

Zinn Online Frame Size Calculator

Tiemeyer Custom Fitting Analysis

Bike fit is a partnership between you and the bike. A properly sized bicycle is comfortable and fun to ride. Always remember… riding your bike is supposed to be fun!