Learning more about fitting bikes?

[bike4ever]

You should measure and fit both men and women the same. You are not necessarily going to use the same frame, saddles, crank arm length, stems or handlebars. The actually measuring should be the same. If you follow a fit program (i.e. Serotta or Bike Fit), then you will just be fitting the bike to the individual.

Please keep in mind, everyone is different. Men can have long legs with short torsos just like many women. I ride a men's 49 Lemond. I have short legs with a long torso. Everyone is different.

[KnottedYet]

The problem I'm running into is fitters (at least, shop employees who are calling themselves fitters, whether they had training or not, I don't know) who are looking at distance from saddle to pedal, without looking at knee-over-pedal-spindle. They eyeball the seat height (placing it up about like they would for a man) check that the woman can touch her heel to the pedal at the bottom of the stroke, but don't look at what happens at the forward pedal position. On a bike, you are essentially doing single-leg squats when the pedal is at it's forward most position. And, just like in a squat, you don't want your knee out front beyond the forward-most weightbearing portion of your foot (generally the ball of the foot) (when you do a squat correctly, your hips go back farther than your knees go forward, but most of us in the "West" have tightened as adults such that beyond a certain point our heels come up and our knees flop out forward) (folks from Appalachia used to be an exception, traditionally they squat to sit on their heels like folks in other parts of the world, and the difference that makes in the articular surfaces of the femur and tibia were enough to help identify unknown soldiers' bodies in WW2.)

So, a woman with a 32 inch inseam plunked onto a bike with a saddle positioned for a man with a 32 inch inseam will have the correct knee angle at the bottom of the stroke (or 2 cm of heel drop, or graze the heel at the pedal, whatever measuring trick you want to use) but her knee-to-pedal-spindle relationship at the forward position will be way off due to the length of the femur vs tibia. (her knee will overhang the pedal spindle and throw her whole body off as it tries to compensate for the sheer stress at the knee and the loss of power in what should be the power section of the stroke)

The secret is really that forward pedal position and the knee-over-pedal-spindle relationship. But if someone is used to fitting men and doesn't use KOPS, he will struggle mightily trying to fit a woman and her longer femur to tibia ratio. It will "look" right, by his knee flexion at lowest pedal position measurements, but something will still be off and all his other adjustments will not help.

Everyone, go out to your bike and have a buddy hold a string with a weight at the end at the bump on the shin just below your kneecap (or on your kneecap if you have trouble finding the bump). Backpedal until your foot and pedal are in the forward most position. The string should cross the crank 0-3 cm behind the pedal spindle. (if your bike has geometry for fast stuff like tris or TT, the string is likely to cross right at the pedal spindle)

Edit: The women who get fitted incorrectly are the ones who end up injured and come to me. So I'm only seeing the ones who were fitted incorrectly. And the error I'm seeing is fitters who only look at knee angle at bottom of pedal stroke when determining saddle position. They put the fore-aft position where they are used to it being for a man, and don't touch fore-aft again after that.