My chain jumps when I am in the small chainring in the front and the small ring in the back. Compound double crankset, Shimano FC-R700, 34/50, 10 speed. The chain is not rubbing on the front derailleur cage and the chainwheels are true. Looking at it closely on the bike stand, the chain is catching on one of the little tabs on the back side of the big chain ring at every revolution. Fairly new crankset. Where do I go from here ? Try a new chain ? I really can't tell if the little tab is bad, there seems to be a sharp edge to it compared to the other tabs but only slight if any. Is it ok to use a dremmel and smooth it out a tad ? Probably not a good idea, but had to ask

Simple fix: don't ride in that cross-chained gear combination.

Guy goes to Dr, says "it hurts when i do This"..

Dt says "so stop Doing that"

Problem solved..


Next Troll ....

Thanks guys, I didn't think of the cross chain thing.

You don't want to ride in the small - small combo. Shift up 2 cogs on the cassette and up to the big ring. It's close to the same ratio gear wise. There's a reason the latest firmware update on Di2 locks out the 2 small cogs when you're in the small ring.

Since my old brifters don't have any gear indicators, once in a while I'll get into that cross-chained situation. On my bike, I can fine-tune the FD so it runs quiet, but I leave it a tad noisy as an alarm not to ride like that.

That can happen on some bikes. Shorter chainstays make it more likely to have issues when cross chained.