How to fit a road bicycle
Here are four easy steps to help you tailor your bike to fit your body:
1. Saddle Height
Take off your shoes and sit on your bike with your pedal in the down position. Adjust saddle height so that your leg is straight (your leg should be perfectly straight with just your sock on ). Put on your shoes, with your right leg at 12 o’clock (the top of your pedal stroke). In this position, your thigh should be angled downward, not horizontal or above your hips. Your other knee should now be slightly bent.
The pedal axle should be directly beneath the ball of the foot. Moving the cleat slightly toward the heal improves power but slows cadence. Your leg should be perfectly straight with just your sock on. Your knee should be slightly bent and the pedal axel should be directly beneath the ball of your foot.
3. Seat adjustments
While seated on your bike and clipped in, position your right leg at 3 o’clock. Hang a homemade pendulum from your kneecap. The pendulum should be lined up with the center of your pedal (the spindle). Adjust your seat forward or backward as necessary. This test is not necessary on some modern bikes, which are designed for better fit.
4. Handle bar stem length
Standing beside your bike, place your elbow at the tip of your saddle and reach your fingertips to the handlebars? They should just touch. If not, you may need a shorter, or longer stem. (In the case pictured, the stem is slightly too long. Your fingers should just touch the bars.)