My bike slid out from under me slipping on a wet grate at a slow speed and the chain got stuck for the first time. Someone I was riding with fixed it pretty easily. It has happened twice more, recently tonight as I was finishing up a ride in the park. I had to stop quickly as some runner on their phone suddenly changed directions. Luckily I was going slowly and I was a block from my apartment. The chain has 1500 miles on it, and I have a new chain I can ask the LBS to put on. Do you think it keeps happening because of something that happened with the FD when my bike initially fell? Should I replace the chain? Should I measure it first and see if it's stretched?

Chain suck is really sucky. But to many chain suck occurs while shifting, not usually refereed to when there's been an incident/fall down. Chain suck is usually thought as the chain failing to release off one chain ring while shifting. This causes the chain to get pulled up and around the crankset on the "backside". In the extreme the chain contacts the chain stay and can get wedged between the rings and frame. Is this what you are saying?

You should have the chain ring teeth checked for wear and/or bent teeth & wobbled rings. The chain should be checked for a twisted link. If all are in good order then look at the front der adjustment and whether you're soft pedaling during the shifting. This last point is very important. many riders don't have the best shifting technique and power during the shifting. This hard pedaling during shifting only makes any existing condition much worse.

Sure you can ask the LBS to install the chain you already have. Don't be surprised if they have a higher labor rate for customer provider parts installs. Also remember that the performance of that chain will not be their problem. Andy.

Gramercy, I think there's a low probability that the chain itself is the problem. I have seen a freewheel, and a freehub like you have operates much the same, not release it's ratcheting mech. and drop a chain at the front when pedaling was stopped.

Brad

possibly the chain/derailleurs not lubricated properly. rear derailleur spring manlfuncioning, chain too long?