Love Thy Knees: Get the Right Fit

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If you ride your bike quite a bit, then undoubtedly you've given a moment's thought to your knees. Protecting them, maintaining them, nourishing them, thanking them. Cycling, however, poses some unique threats to our most fragile joint. The sheer repetition, the (at first) unnatural position of the bike, the cold weather and wind chill.

Oh, how have we lasted this long?

Fear not, with a few simple precautions you can avoid unsavory afflictions and ride year-round.

Bow to the Guru and Get Fit

Dr. Andrew Pruitt, Ed.D., is the clinical director of the Boulder Center for Sports Medicine, a widely-published writer on cycling and athletics, and a regular consultant to the U.S. Cycling Federation. Dr. Pruitt sees the country's finest cyclists and athletes from his Boulder, Colorado, practice. He's also a two-time world cycling champion (1985, 1987).

Position on the bike and the "fit" of your ride is probably the most important part of avoiding knee injuries. Short of coming to visit Andy in his office for a custom fit, your next-best option is to spend time establishing proper position on the bike at home. You can get plenty of help from any of several books like Greg LeMond's Complete Book of Cycling, or Ed Burke's High Tech Cycling, but here are a few tips from Dr. Pruitt himself.

The Right Height

The most important component to bike fit is finding an appropriate seat height. This is your effective distance to the pedal from where you sit on the saddle. There are a lot of competing formulae out there, but Dr. Pruitt's numbers are the last word on keeping your joints happy.

Riding with an improperly positioned saddle will decrease your efficiency, increase discomfort on the bike, and invite all manner of nasty conditions like iliotibial band syndrome, chondromalacia and mental disorders (alright, that's stretching it, but you'll be bummin' if you wreck your knees).

Dr. Pruitt says of saddle height, "90 percent of your barefoot inseam is an appropriate starting point." Stand in bare feet and have someone measure your inseam from the floor to your crotch. The idea of someone measuring you not sit well? Then do it alone by standing with your back to a wall, put a yardstick between your legs, parallel to the ground, in slight contact with your crotch and then mark the wall behind you with a pencil.

"Take that number and that's your height from the center of the bottom bracket to the top of the saddle," explains Dr. Pruitt. Take that figure, 90 percent of your inseam, and measure from the center of the bottom bracket at the outside of your crank arm (there will be a crankarm bolt there, measure from the center) and set your saddle accordingly. Be careful to hit that 90 percent figure as closely as you can to the top of the saddle in line with the seat tube.

Slide That Saddle

Now we need to position your saddle "fore and aft" to make sure you're sitting in your prime pole position. Notice your saddle has rails beneath it which allow you to position it forward or rearward. Doc P again reminds us that while his system will get you in a great spot, it's not necessarily a hard and fast rule for finding fore and aft. Generally speaking, you want the front of your kneecap to fall above the end of the crank arm when it's in the three and nine o'clock position.

Am I talkin' Greek here, gang? Position your cranks so they rest at three and nine o'clock (parallel with the ground). "I prefer a straight edge, like a meter stick. Take the meter stick straight up from the end of the crankarm (not the pedal, but the rounded point where the crankarm ends) and it should come to the front of the knee cap (of the front leg), not behind it, not below it," elaborates Dr. Pruitt. Like saddle height, there are a variety of methods for determining fore-aft, so if you know of a way that works for you, stick with it.