KC8QVO

Is the pain that you are stating as being "behind" under/behind your knee cap or in the back of your leg?

Several years ago I had knee problems from riding where my knee caps were pulled to the outsides of my legs, respectively, causing the knee caps to grind the joints from sideways pressure. It was an internal pain/behind my knee caps that caused my legs to lock up. It put me on the ground a few times. I was reluctant to have it looked at because I was at the end of the season and wanted to hit my mileage goal so I hammered through a couple weeks and slowed the miles down.

Long story short - when I finally got things checked out with X-rays etc and they found the issue I ended up in physical therapy for a couple months. It was an imbalance in strength where the muscles and tendons to extend my legs were built up, but not the opposite. I had platform pedals so all I could do was push - not pull.

After physical therapy and before I got to riding again I got clip pedals and shoes (SPD's). I went through a few pedal designs and landed on a combo SPD on one side and platform on the other. Since the pedal/shoe change I've never had knee problems since.

The question was asked if exercise can resolve the issue. I think that is an "it may" answer. It may resolve the pain and overcome the injury aspect. However, it may not be a solution to the cause.

In my case, the cause was that I was exercising half of my legs. So to get me over the injury exercise (physical therapy - lots of it) did the trick, but changing the pedals/shoes fixed the cause.

If you can find what motion sets the pain off that may lead you in a better direction. If you have the ability to sit on the other bike and get some pictures of your posture and pedal strokes that may lead to some alignment changes as well. I did that when I was in physical therapy - the place I went to had me bring the bike in and took measurements etc to see how my body was aligned on the bike.