I've ridden the fixed gear a lot lately but ride a geared bike some. Today i rode the geared bike through lots of rollers with a group. I would use a fairly high cadence with considerable pressure up the short climbs. About half way through the hilly section I got tendinitis below and to the outside of my right knee (weak knee due to ACL injury 30 years ago). It may be my bike set up. I will work on that some. But I was wondering if riding fixed a lot with the pedal automatically coming up weakened muscles resulting in the tendon problem where I was pulling up and back spinning at good cadence and power on climbs. In other words maybe I lost fitness for geared riding! Flats weren't a problem where I could spin at speed but not have to put a lot of pressure on pedals. Anyone experience something like this? I know the answered-"quit riding a geared bike"-lol.