Chain popped off on the ride back and jammed into the wheel, went to undo the rear wheel and realised that the axle (and hub bit) was turning with the locknut on the drive (chain) side, so I had to bring the bike back, grab a 17mm to jam into the hub side to stop the axle from turning. What's the issue here - have the serrations on the wheel hub somehow worn down and is that a part that can be replaced?
Chain popped off on the ride back and jammed into the wheel, went to undo the rear wheel and realised that the axle (and hub bit) was turning with the locknut on the drive (chain) side, so I had to bring the bike back, grab a 17mm to jam into the hub side to stop the axle from turning. What's the issue here - have the serrations on the wheel hub somehow worn down and is that a part that can be replaced?