So I recently sold a bike to a fella and it does something weird. While shifting from the middle chainring to the big one sometimes the chain just skates around between the chainrings and often just gets stuck. It's a triple and it doesn't happen between the middle and small one. I fiddled with it myself and adjusted the front derailleur to the best of my ability and it still did it so I took it to a shop. He started adjusting it and quickly broke the clamp so he replaced the derailleur and adjusted it. It still sucks the chain between the chainrings.



What could it be? The limit screws are adjusted properly so it doesn't fall off to the in/outside.

Wild guess? Wrong size chain (too narrow)?

i was having this problem while using a slightly worn chain; replacing it with a new one eliminated it.

One of the rings may be machined slightly offset, and is installed reverse of what it should be. Examine to see if the chainring bolts are sitting recessed as they should (though not applicable on some French cranksets, particularly Stronglight).

Alternately, the chain might simply be too narrow for the purpose - is it a 9 speed chain, by any chance? Try putting on one of those wide Taya chains in its place.

-Kurt

+1...This happened to me. I was in a hurry swapping out some chainrings onto another set of crank arms and installed the small ring backwards. The chain kept falling in between until I flipped it around.

Thanks for the hints and info...He's coming over this evening so I'll slap a new chain on it and check to make sure the rings are installed properly.

Learn something new every day!