I know what you mean. After about 60 years of doing a left-side leg press every time I accelerate from a stop on my track and fixed-gear bikes, as well as struggling up inappropriately steep climbs in a 71-inch gear, I'm left with a pretty bad left knee. Not yet painful, or not all the time, but it never lets me forget.

I'm thinking of getting a 110-BCD Hollowtech II crankset for my current fixed-gear bike and installing one of the 42-tooth Biotech rings I still have stored somewhere.