My left pedal is sending a slight knock to the sole of my foot at every turn, at the 1 o'clock position. What could cause this? It happens on all chainring-sprocket combinations though not with the same intensity.
Edit: this is a flat pedal, JIS square taper bottom bracket.
Edit: By "1 o'clock" I mean there's a click in the left pedal when the right pedal is exiting its power sector/downward push, and the left pedal is about to come "over the top" ready for its own power stroke.
Edit 2: Solved! This is a brand new crank set that I installed onto a year-old bottom bracket. I must have installed the left arm wrong. I took it off, cleaned and re-greased the crank bolt tread and the faces of the square tapered spindle, put everything back together, tightened with care, and the knock is now gone.