Originally Posted by
AdkMtnMonster
Could be a little patellar tendonitis or even bursitis. Make sure your saddle is at the proper height and that you’re not trying to push too big of a gear at a slow cadence. Both of this can cause knee pain, as well as lots of other things, as noted above.
Interesting insight about the high gears. I've been riding around with my kids and just selecting the highest gear possible for more effort while going slowly with them. Guess what, I felt some weirdness with my knee and was wondering what's going on!