Originally Posted by Ti473

I had a bottom bracket cup loosen up on me today on a ride. It needs a somewhat specific spanner wrench to tighten which I didn't have on me, and which is probably why it came loose in the first place since I can't properly torque it. To make things worse this is an eccentric BB for a single speed conversion, which meant the chain kept tightening and the crank spindle would be out square.
Now my question is... I thought that BB reverse threading is done so that the cups self tighten as you pedal, am I wrong?
But if I look at it from the drive side for example, you tighten the BB cup CCW and you pedal CW. So doesn't pedaling actually loosen the BB? What am I missing here? Sorry if this is a dumb question