Question: I’m 5-foot-4 and like to push a big gear. I’m getting ready for a time trial. My coach had me change my crank length to 165 mm because I rock on 170s and therefore lose some momentum. Since I’ve been riding with the shorter cranks, my left knee hurts. What could be causing this? Do you agree with my coach’s advice? — Rodney P.
Coach Fred Matheny Replies: Generally, if you’re rocking on the saddle, it’s probably too high. Changing to shorter crankarms addresses this in one respect by shortening the reach to the pedal at dead bottom center.
But it’s better to have the correct saddle height to begin with. To be sure, get a bike fit from a cycling coach or pro bike shop.
When you change crank length — or make other major alterations in bike setup — it’s not unusual to experience revolt in your knees or other joints. You’ll probably need several hundred miles on the shorter cranks to adapt.
Get your saddle height right and that should quicken the process.