A correct bike fit makes a huge difference when it comes to speed, comfort while riding and avoiding injuries. Here are some tips to consider to make sure your fit is correct.
Wind-tunnel tests have proven that being narrow on the bike is much more important than being low. Most of us can improve efficiency the most simply by keeping legs and arms in line with our bodies, not splayed into the wind. A handlebar no wider than the shoulders is key.
Make a fist and measure across the four knuckles. The difference between the top of your saddle and the top of your handlebar should not exceed this number. An easy way to check is to set your fist atop the handlebar (vertically, pinky down) and have a friend eyeball the fist/saddle relationship from a few feet away.
Your most comfortable riding position should be with hands on the brake lever hoods. This is the “neutral position” from where you can move to the tops near the stem or the drops. When you get the on-hoods position right, these other locations will be usable, too.
Your reach to the lever hoods should put your wrists in the “handshake position.” That is, a straight extension of your arms, not cocked up or angled down, which can cause strain and pain.
Your knee bend at bottom dead center of the pedal stroke is a better indicator of correct saddle height than numbers produced by leg-length formulas. For most riders, knee bend should be within a degree or two of 30 degrees.
To get the correct knee bend, a traditional method still produces a very good starting point: With your bike mounted level in a trainer, sit square on the saddle while wearing your cycling shorts and shoes. Put your heels on the pedals. Pedal backwards. Adjust saddle height till your knees straighten but hip movement is minimal. Then when you clip in, knee bend will be on the money. You can also check this on a ride by pedaling with your heels (not when there’s traffic, of course).
The benefit of a bike custom built for your body dimensions is not to automatically put you in a perfect position, but to put you in a “fit window” of 1-2 centimeters. Then you can tweak things to maximize comfort and pedaling efficiency.
When all is said and done, your riding position should put 60% of your weight on the back wheel and 40% on the front. This is important for bike control as well as comfort.
Fit is not static. Stay aware of how your body reacts to riding and make position improvements as necessary. Various things affect fit over time, including simply getting older and losing flexibility.
If you are dealing with discomfort or an injury, consider seeing a professional bike fitter who is certified by the International Bike Fitting Institute. Sometimes a pro can instantly spot problems that you’re missing on your own.