Comment by mauvehaus

I work in a bike shop and still fuck this up periodically. It's especially confusing because some pedals only remove from the "back side" with an 8mm Allen wrench.

The easiest way to get it right is if you have a ratchet and a 15mm crow's foot socket. Set it for lefty-loosey before you attack the left side of the bike and you probably can't go too far wrong. Of course, if you have a breaker bar out, this doesn't work.

The other left-threaded bit on a bike is the drive-side of the bottom bracket. Spoke nipples appear to be left threaded, but that's because in the usual case, you're looking at them from the wrong side in a truing stand.