|
From what you described, the chain needs to be tightened a bit. Chain stretch wouldn't normally cause it to jump off the chain ring. I imagent when you go over a bump, you foot is at 3 and 9 o'clock acting as shock absorber, meaning no force or turning on the pedals therefor chain bounces off the chain ring. Another place often over looked is the chain ring bolts. Tighten them up a bit. Maybe one or two had come loose.
|