Originally Posted by
jbonamici
I'm intrigued by the bent hanger theory but can't quite get my brain around the mechanics of it - anyone care to explain?
Because of the closeness of the dérailleur to the rear cogs, a bent hanger would induce a sharp angle in the chain. Thus the chain wouldn't want to ride on the cog. To counteract that bend, you would have to shift the derailleur such that it was not really where it would normally be to happily ride on the cog. So it would be very touchy.