Broke Something, Can't Figure Out What...

Went out for my usual 20 mile ride this afternoon. On the last couple of miles i decided to see how well i can do against a UPS truck from a dig (stop). So as I was going and i was shifting the rear derailur and i get in front of the truck. Then the next thing i know when i put my "foot down" it skipped. And my chain is "skipping" whenever I apply force to the pedals, like something is not catching... I don't know if i broke a link in the chain or maybe a cog. Anyone have any ideas?

From what I see everything looks fine

 

Check to make sure that your cassette lock ring is tight, that your derailleurs are adjusted properly and that all of the cogs are intact (take the wheel off and visually inspect as well as wiggle each one) Cogs can rarely crack.

 

If the chain is skipping, see if you have a lazy link in there somewhere, due to a buildup of road crap , this would happen to me as a messenger sometimes with my work mule. FLexing the offensive link would relief it on the road but a good cleaning was the rule to fixing it. OR it's simply time to replace possibly.

 

If the chain is skipping, see if you have a lazy link in there somewhere, due to a buildup of road crap , this would happen to me as a messenger sometimes with my work mule. It has been known to be the freewheel letting go. Either way a good cleaning outta do it. Or if quite old replace.

 

Does the chain skip on every sprocket and ring?

 

Were you using gears that you don't normally use?

If so, my guess is that, because you were hooning along behind a truck (cool fun, isn't it!!), you probably pounded on the 12 or 13 cog like you haven't pounded for a while, so, the uneven wear of the big gears was exposed because of the extra torque.

Either that, or your big gears aren't perfectly in tune, and it wasn't noticeable until you really pounded them!


I guess you could have a stiff link -- sometimes stiff links don't cause trouble until they get around the "sharper bend" of the smaller cogs.

Aside from checking each link manually, to check for a 'stiffy', flip the bike upside down, put it in a smallish cog, make sure it's perfectly in gear, then slowly spin the pedal backwards whilest looking down along the chain, focusing on the jocky wheel. Check for any link that ain't in line with all the others.

 

When I "got on it" i was using gears that i normally use when i "get going." Then I downshifted so I could but less strain on everything (I thought the chain was gonna go and I had ways to go to get home) and when I gave it some torque to get over some hills and what not, it still skipped

As far as i can see the chain and the cogs looks good, but thats just me. I just recently brought the bike into a shop and had a tune done. The bike shop really did charge me a lot and did a shitay job, so Im wondering if they are responsible. It doesn't matter because I'm not going to bring it back there. If I only had the tools to do it myself...

 

Have you checked that the freewheel only freewheels in one direction ?
They can break quite frequently in some circumstances ( know a girl mtb rider on her third in as many years )

 

When this happened to me, I coudn't get it right until I had replaced the chainrings, chain and cassette. But if Ingles' guess is correct, and it could be, even that won't do it.

 

just got a new ultegra casette and everything works just fine. The new chain wasn't exactly aligned up with everything on the old casette and was causing some unnecessary wear and tear and now everything is ok