Worked a day and a half putting back the drive wheel etc. Have a new # 41 chain, got her all tightened down with new chain on and turned the wheel to make sure all was going well and it was great. Put on a new chain tension arm with the spring and all was well. Turned the wheel about a half of a turn and the chain came off. Tried twice and came off. All was in line off no more than 1 /8 inch . I am thinking the chain tension arm is causing it. Otherwise done. No where to turn except build a new bike using something better in drive train and bike. Sorry to complain guys just aggravating as **** . gphil