# Chain pops out of gear



## tc529 (Nov 3, 2008)

A couple of weeks ago I had a flat on my back tire, slowly I noticed that when really baring down on the crank the chain pops out of gear. It has slowly progressed into multiple pops. I am taking it to the LBS because 1 contract 2 the guys there are good and I always seem to buy something.
The thing is I want to know how to adjust it myself and I asked at the shop but the fix it so quickly I miss it. 

My wife thinks I have a girl friend because of all my charges at the store. It would probably be cheaper.

Seriously is this just a quick adjustment?
t


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## InvictaS1 (Mar 19, 2005)

sounds like one of your derailleurs is out of adjustment. check out the park tool repair section http://parktool.com/repair/.


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## xenon (Apr 16, 2007)

It depends. Normally, if the chain pops on all the gears, it is likely just cable tension needs to be adjusted, which is simple and quick. It may be also worn out chain (I guess, not your case, if your bike is still under warranty) - then it should be replaced.
One more possible cause - bent derailleur hanger. Usually, it means, low gears work well, high ones don't, or vice versa. Then the hanger needs to be straightened, at the shop (better, as they must have a special device), or at home by eye.
For guide lines look here:
http://www.utahmountainbiking.com/fix/ , enter the "derailleur tuneup" in the left frame.


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## tc529 (Nov 3, 2008)

Thanks for the website I found the rear deraileur adjustment section and will go through the steps. Is the cable strecher a necessary tool?


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## xenon (Apr 16, 2007)

No tools needed. To adjust the cable tension, you may just use the barrel adjuster on the shifter or on the rear derailleur itself (look where the cable enters the shifter or derailleur). For front derailleur - on the shifter only. 
By screwing the adjuster clockwise, you loosen the cable, thus moving the rear derailleur towards higher gears.


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## Boyonabyke (Sep 5, 2007)

tc529 said:


> A couple of weeks ago I had a flat on my back tire, slowly I noticed that when really baring down on the crank the chain pops out of gear. It has slowly progressed into multiple pops. I am taking it to the LBS because 1 contract 2 the guys there are good and I always seem to buy something.
> The thing is I want to know how to adjust it myself and I asked at the shop but the fix it so quickly I miss it.
> 
> My wife thinks I have a girl friend because of all my charges at the store. It would probably be cheaper.
> ...


Ever heard of RTFM? See who makes your derailleurs, find out the brand and model on your bike build, and look up the instructions on line for that model, from SRAM or Shimano. You should be able to find the instructions online if you use your PC for applying yourself instead of surfing P0rn sites, or other junk online.


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## FBinNY (Nov 7, 2008)

The fact that it pops out of gear only under heavy load may mean it's something different from a derailleur trim issue. I'm also not sure what you mean by "pops out of gear". If you mean changes gear on it's own check trim, if you mean it skips - disengaging from the cog momentarilly under load - it's probably a chain/cassette wear issue.

In any case, check derailleur trim first since it's so easy, but if the problem persists check your chain for wear.

*No tools needed*, except a 6" or 12" ruler. Either have someone hold the bike or lean it on a wall in a corner with the front wheel touching the other wall so it can't roll. Push down on the pedals to tension the upper chain and measure the on-center distance between the pins 6" or 12" (12 or 24 links) apart. If they measure almost exactly 6 or 12" the chain is relatively new. Probably they'll be beyond the exact 6" or 12" mark, because the chain has "stretched" slightly due to wear. Generally the limit of alowable stretch is 1% or 1/16" per 6", (1/8" per 12"). Chains worn beyond this point will run rough, excessively wear the cogs and chainrings and/or skip under load, and should be replaced ASAP. With luck your cassette may still be usable.

BTW- a number of firms make chain stretch gauges but they're usually less accurate then this method, and anyway why spend dough.


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## Frozenspokes (May 26, 2004)

Everyone seems to be missing one important peice of this puzzle. The OP stated that the "popping" out of gear started AFTER having a rear flat. It may be as simple as the rear wheel not being seated in the dropouts properly. BTW, this is called ghost shifting. 

Open the quick release lever and push down on the saddle and then close it again. Then give the bike a test ride. If the ghost shifting stops, that was your problem.


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## Fibula (Oct 20, 2008)

Or the cassette or bearings is loose.


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## dan0 (Oct 12, 2005)

listen to frozenspokes


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## tc529 (Nov 3, 2008)

Thank for the number of responses, sometimes real solutions cant be found in a manual. 

As for the solution that actually fixed the problem
It was a combination of Frozenspokes setting the tire and xenon solutions the barrel adjustment on the rear derailluer.


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