I noticed on my last ride that I could hear a freehub while coasting, I wasn't initially concerned as I'd just had a new hub fitted on the rebuilt back wheel. I've noticed today that while pushing the bike, or at any time while not coasting with the feet on the pedals they rotate. This is causing a lot of drag and the locking chain nut to come completely loose while riding. Any body had this issue before and is there an easy fix without having to get the motor sent off for service.