So I have a bike equipped with 2200 brifters, an 8-speed cassette and a Sora RD. The issue i have is that if I go over a particularly big bump (or if I just roll my bike down some stairs), the chain will come off the chainring. Obviously it's pretty easy to fix most of the time, but once it somehow got jammed between the chainring and the frame and it took a good 20 minutes to pry it out, which not only made me late but also took a chunk of metal out of the frame. So my questions are:

1. Would upgrading the RD do anything to solve this problem? If so, what level (tiagra, 105, etc) would provide a noticeable improvement? If not, do you have any other suggestions?

2. Is a 10-speed RD even compatible with 2200 brifters and an 8-speed cassette, or would I have to change those out as well?

3. If I were to have to change out the cassette (you can see the progression of questions), would I be able to install a 10-speed cassette on the same hub that the 8-speed one is on now?

Thanks.

The chain never comes off while shifting, - only while going over a bump?

Did it always do this? Is it a triple? Does it only happen in the small ring?

Sorry for the 3rd degree, I'm just curious. The only thing I can think of is that the derailleur has a weak spring or maybe the chain is too long.

There is a gizmo called "chain watcher" or something like that which attaches to the seatpost and keeps your chain from falling off the inner chainring.

A 10 speed derailleur will work fine with your current brifters. I believe 8, 9, and 10 speed cassettes will all fit on the same hub.

The chain did come off while shifting once, but that was an issue with the FD and never happened again after I adjusted it. It's a double chainring (36/50 or 38/50?), and it's never jumped off in the fashion described while in the big ring.

To me, it sounds like the chain is probably too long. The RD should be almost as far forward as it can possibly go when you're shifted into the big/big combination.

I believe that you need to stay with an 8-speed cassette if you are using 8-speed brifters.

What you have is very possibly a case of you chain being too long. Long enough that the dérailleur doesn't keep it under enough pressure when in small - small. You may knock out a link and see what happens.

When I measure out chains I will wrap them directly around the big front and big back cogs, no dérailleur. Then I will add a full link. This tends to give it just enough slack to run in the big - big combination.

Before taking any links out of the chain, make sure the RD is pivoting freely. If you shift to small/small and see the chain suddenly start hanging, it might be that the RD can't pivot. Time for some WD40.

Thanks for the tips everyone. I went ahead and removed a chain link (before and after big-big photos are attached), though I've yet to see if it helps with chain retention.

The tension is important when you have it on both small cogs, front and back. On big - big, it's only important that it have enough slack to operate correctly.

Your front dr limmit adjustment needs to be set if this keeps up after making the chain shorter.

Maybe tighten the B screw. It increases the tension of the drailieur spring.

It looks like your chain was possibly too long before you removed a link. I always had a problem with my chain hitting the chainstay on my old bike when going over big bumps, mostly because the chain was too long. You could also check the FD low set and set the inner part of the FD cage to about 2mm clearance from the chain when it is on the small-small combo, might help keep it from flying off to the inside.