Does anyone ride two different crank lengths on their various bikes? I've got a 170 on my hybrid commuter but my new road bike (52cm Rocky Mountain Sherpa) has 175s on it. I think that's mighty long for that frame size but I'm willing to ride them if it won't hurt my knees. I notice when I do one-legged stroke exercises that there's a big old dead spot at the top of the stroke, I guess because my leg is not used to pulling up that far.