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Bike Fit

His subjects were a group of top-ranking junior riders at the Olympic Training Center in Colorado Springs. The tests produced some startling results. Riders who were incorrectly positioned on their bikes were giving up significant power compared with those who were properly fitted.

In fact, on some of his subjects, Hodges calculated this loss of power to be the equivalent of adding a rude 15 pounds of unneeded body weight.

With that in mind, here are some basic tips that will help you set up your bike quickly and improve your riding efficiency and power.

  • Saddle height

Hopefully, you have a bike that's close to the size that's good for you, with about 4 1/2 - 5 1/2 inches of the seat post showing. (More on frame size later.) Mount the bike on a wind or mag trainer. You should pedal easily and stop with one foot at the bottom of the stroke. Using a goniometer (an angle-measuring device), determine the amount of bend in the knee, and adjust the seat height accordingly. The goal: 30 - 34 degrees.

If you do not have a goniometer, raise your saddle until your hips rock slightly when you pedal. Then lower the saddle just enough to eliminate the rocking. Record the distance from the pedal axle to the top of the saddle, and commit it to memory.

  • Fore/aft saddle position and tilt

With the bike in a trainer and seat height set correctly, stop pedaling when the crankarms are horizontal. A plumb line (string and weight) dropped from the front of the kneecap should touch the end of the crankarm. Slide the saddle forward or back on the rails to get it right. Once seat height and fore/aft adjustments are correct, use a level to be sure the top of the saddle is horizontal.

Some riders like to tilt the nose of the saddle down slightly (1 - 2 degrees) to avoid numbness.

  • Reach to the handlebar

There's no formula for this — ride the bike for at least 15 minutes, making sure you are comfortable with no sharp bend in the back. Most road bikes are set up for a stretched-out racer, but I suggest a more upright position that uses spacers in the headset, a frame with a shorter top tube or a stem with rise.

Here is another way to set up reach. While looking down with hands on the brake hoods, the handlebar should obscure the front wheel's hub, or fall slightly in front of it. If you can't achieve this with a normal, 8- to 12-cm stem, you may need a frame with a shorter or longer top tube.

  • Frame size

With the above parameters set correctly, your goal is to have 4 1/2 to 5 1/2 inches of the round part of the seatpost sticking out of the frame. Also, the vertical difference between the top of the saddle and the top of the stem should be 2 1/2 to 3 inches for racers and 0 - 1 1/2 inches for everyone else.

If the frame is too small, it will be hard to raise the stem sufficiently. Consequently, many bike fitters have gone to larger frames with shorter top tubes to fit many of their customers.

  • Cleat alignment

Sit on a table with your lower legs hanging straight down. Check how your feet naturally align — toes in, toes out, or straight ahead — then duplicate these angles when you install the cleats. Fore/aft cleat position is correct when the pedal spindle is directly under the ball of the foot (widest portion of the shoe).

Use several short rides to fine-tune the adjustment for maximum comfort and pedaling ease (carry the necessary wrench in your jersey pocket). Keep in mind that most current clipless pedal systems have 5-10 degrees of "float," allowing your heel to move laterally. Position your cleat so the foot is positioned in the middle of this range.