My drive side crank arm loosens periodically at the BB bolt. There's no back & forth play, it just shakes a little from side-to-side. I'll stop, re-tighten the crankbolt, and continue on my way. I've read up on other posts about how it could be my crank or the BB spindle deforming, necessitating a new crank arm or set as well as possibly a new BB. But this thing is almost brand new, maybe 30-40 miles on it. I haven't taken the cranks apart yet, thought I'd throw this out there first. I've been practicing skid stops a bit, is that the culprit? I wouldn't be surprised if it was except for the fact that the cranks and BB are pretty fresh and not old and beat up. I've torqued everything down to just short of stripping the threads (I think .