Big chain ring problem – any advice?

[Fitch]

A technical bike question, and please forgive me lack of knowledge on the proper terminology.

I’m looking for the proper term/ analysis for this problem. SITUATION: I’m pushing my way up a climb, pressing hard into the pedals, and the chain skips off the big ring, dropping the gear and stopping me. This A) sucks, B) is incredibly annoying, and C) normally hurts Little Fitch when I bounce off the seat.

Question 1) What’s the term for this happening?

Question 2) It seems to me that this means I need a new chain because the teeth of the gear obviously aren’t holding on as they should.

This has become a significant issue over my past three rides and is preventing me from climbing the way I want to. Any help at all is appreciated.

Thanks!

[GoldenGoose]

1. chain jump or chain skip

2. it can be caused by several things…

chain stretch- as they get older they stretch and don’t hold the cogs as well

cog wear- the teeth wear out from constant chain friction over time making the chain skip

poorly adjusted derailleurs- they can try to shift you into a gear you don’t want to be in. check your high and low adjusters and tweak with the barrel adjusters.

dirty or damaged cables and housings- they will stretch and fray and basically won’t hold the right tension on the derailleur to keep you in the correct gear. dirty housings catch the cables inside and wreak general havoc on shifting.

loose components- loose cassettes or front cranksets will slip under load and cause the chain to jump. also check to make sure your rear axle is tightened down correctly.

Does the bike only jump in one specific gear? If so, that cog may be wearing out and need replacement. If it was doing it in multiple gears I would think it’s probably a cable/housing issue. If you know how to work on your bike this is all stuff you can check pretty easily at home. If you aren’t bike repair savy, though, take it to a shop and have them look at it. If you want to try it yourself but aren’t quite sure what to do, just ask here and I’m sure that between myself and the other people we can get you headed in the right direction. Most everything I mentioned can be fixed or adjusted with a screw driver and a wrench. The only specialized tools you might need would be a chain whip to get the rear cassette off.

Good luck and let us know what you figure out.

[Fitch]

Thanks, Jeremy! To start, I’ll put a new chain on, since it’s overdue anyway, and then make sure my cables are all nice and tight. I haven’t done any real maintenance on my bike in about 300 miles, so it’s probably due for some TLC. Thanks again!

[GoldenGoose]

You may have [i:5fz22cgr]some[/i:5fz22cgr] cable stretch but if it [i:5fz22cgr]is[/i:5fz22cgr] a cable issue it’s probably because fraying, kinking, or dirty housing. Try cleaning the cables and housings first. Some types of housing work a little better with a few drops of chain oil or Tri-flow inside of them to cut down on cable friction. Not ALL cables and housings require lube though, so make sure you know what you have first. Some brands specifically say NO lube. Cleaning the housings and cables is really something that should be done at least once or twice each biking season so even if it turns out to be something else, it’s a quick and easy preventative measure to take. I’m always amazed at how much smoother my bikes shift after a proper cleaning of the housings and cables. That gunk just piles up so slowly that you don’t even realize how bad it has gotten. Good luck on getting your baby back in top shape.

[Author]

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