Crank Length and Knee Pain Advice Needed

I got a new bike about 6 weeks ago and I just had my second fit adjustment as I've been having pain in my upper hamstrings and especially in both my knees.  The hamstring problem we've isolated to the seat not fitting well.  I got a new seat a couple of days ago and my hamstrings (and rear endO are doing much better.  My real problem is my knees.  i've had a history of Chondromalacia and the pain I'm having is under both kneecaps.  The pain is a dull ache most of the time, sometimes waking me up at night.  Not a good situation for my 50 year old knees.

I've been reading that crank length can have an affect on this kind of pain.  During my last fit, I found that my new crank is 175mm while on my old bike (where I didn't have the problem) the crank is 170mm.  The bike fitter didn't suggest a new crank, but I think this might help.  My inseam is 32 inches, for which I think 175mm is kind of long.  One thing I notice is I get more discomfort pulling up on my pedals.  In any case, it seems it would be a good idea to have both bikes with the same crank length, since I will be using the old bike on my trainer.

Any advice would be appreciated.

Edited by nickster 2009-05-10 2:10 PM