Cycling is one of the best sports for your knees because there is no impact and it is not weight bearing. On the other hand, an incorrectly adjusted bike can put tremendous strain on your knees because it throws you out of alignment and forces you to move in an unnatural way. Your knees are hinge joints, which are meant to move forward and backward with no rotational movement. The wrong seat position, crank length or cleat position can put an inward or outward pressure on your knee joints, causing pain.
Step 1
Measure your inseam and multiply it by 0.883. This should be the distance between the top of your saddle and the center of the bottom bracket. When you sit on the bike and put your foot on the pedal in its lowest position, your knee should have a 25- to 30-degree bend. Adjust the seat up or down as necessary.
Step 2
Sit on the bike with your foot on the pedal and position the pedal to its most forward position. An invisible line drawn down from the front of your knee should touch the ball of your foot and the pedal's axle. If the line falls behind the ball of your foot, adjust your seat forward. If it falls in front of the ball of your foot, adjust the seat backward.
Step 3
Multiply your inseam measurement by 5.48 to find your correct crank length. Most people use a 170mm crank, but people with longer or shorter legs than average leave themselves vulnerable to knee injury from "reaching" for the pedals. If you have very long legs, you may even need a slightly longer crank.
Step 4
Allow your foot to rest naturally on the pedals and ask a friend to mark the position on the soles of your shoes from underneath. The mark should signify where the cleat must be in order for the ball of your foot to be centered over the axle at its natural angle, usually just inside the big knuckle of the big toe. Even if your cleats have float, it is important to position them appropriately the first time to avoid rotational stress on your knees.
Tips and Warnings
- Have yourself professionally fitted at your local bike shop for expert analysis of your riding posture and custom adjustment help.
- If your knee pain is the result of a previous injury, consult your doctor.
