Re: drive sprocket
I have run into similar problems with my builds but I usually don't sweat it. Usually after about a mile or 2 the chain and sprocket break in and they mesh fine. I do suggest that your chain tension be adjusted correctly though, sounds like you had it a little loose if it was hitting the tire. I just tweaked the tensioner to move the chain away from the tire and also the shorter the chain the better. If you can remove links I would.