Last week on my afternoon commute home from work I bent a tooth on the big ring on my road-bike. I've got a Truvativ Elita compact crank and I thought it was a fairly sturdy setup; but now I'm not so sure.
Here's what happened, as best I can figure out. As I was riding home I was cruisin up a slight grade. I was approaching this intersection with a red light. As I got closer to the light I poked the shifter to drop down to the small ring and started to spin the pedals slowly - preparing to unclip. Just then the light turned green and I grabbed some shifter again (back to the big ring) and the stood up to hammer through the intersection.
Instead the chain dropped off the inside and I'm going nowhere fast. I unclipped, stopped, restrung the chain, and I was off again. But it didn't take long until the clicking sound every revolution of the crank told me something was screwy. I bent the tooth that's right at the crank arm - and it tore the chainring a bit too!
I know all about proper shifting - and though I wasn't exactly following the text-book I think I was pretty close. I had the cranks turning at all times. And I'm not that much of an animal that I can attribute it to my sheer power.
Ever had this happen to you? Anyone? Anyone? Bueller?
My chain was dropping off the outside when I was in the 50 tooth outer ring and the smallest cog in the back. Brought it into my lbs for a tuneup and he diagnosed it as a bent tooth. He tried to bend it back but it didn't work. He said I needed a new chain ring.
Since it's not that big a deal, I just opted not to shift into the smallest ring to save some money.