Chain jumping off at rear

[Azi]

Hi guys,

 

Having a problem with my rear cassette/deraileur and chain. The deraileur can't seem to keep the chain on the second and third biggest gears - I get a constant 'ticking' sound, like the chain is trying to change gear without success. I bought the bike second hand. The bike was serviced a few months ago, and no change, despite me taking the bike back (a different gear ticks now). It has Ultegra components on.

 

Another question while I am at it - is it normal/fine for the front derailuer to move to three different positions, despite only having two rings on the front? Is this a compatibility issue, or should this not be a concern?

 

Any assistance would be appreciated - I am a newbie and have no technical knowledge - don't want to send the bike in for another service or for parts without having an inkling of a possible solution.

[Zac.A]

I've got sram force and the front derailleur has 3 positions, my rear derailleur also clicks sometimes, not sure what to do about it, don't think its too major though, might just be a setting on the derailleur you have to change.

[Tankman]

Hi guys,

 

Having a problem with my rear cassette/deraileur and chain. The deraileur can't seem to keep the chain on the second and third biggest gears - I get a constant 'ticking' sound, like the chain is trying to change gear without success. I bought the bike second hand. The bike was serviced a few months ago, and no change, despite me taking the bike back (a different gear ticks now). It has Ultegra components on.

 

There are a couple of things to look out for.

1. Cable tension might need adjustment. Youll see a barrel adjuster on top of the RD where the cable goes into the RD.

Turn it clockwise one click (1/8th) - test your shifting and repeat. If your shifting got worse - go anit-clockwise.

If you have no barrel adjuster on the RD, look at the shifters for an inline adjuster or one on the frame (and make an note to have the in line adjusters removed next time you replace cables, they are crap)

 

Try that first then Ill give you some more pointers ...

 

Another question while I am at it - is it normal/fine for the front derailuer to move to three different positions, despite only having two rings on the front? Is this a compatibility issue, or should this not be a concern?

 

If the FD can shift 3 times, it is supposed to be used with a triple crank. You have only two chainrings. You are going to keep dropping the chain if you shift one too many times. (not sure to what extent the limit screws can help here)

So not quite normal/fine but it can work if you are happy to remember not to shift more than once up or down.

 

Any assistance would be appreciated - I am a newbie and have no technical knowledge - don't want to send the bike in for another service or for parts without having an inkling of a possible solution.

Edited July 11, 2011 by Tankman

[Hector]

My 105 Shimana also has three clicks on the front. This is not for a third chain ring but to trim your front chain from rubbing against your front deraileur when you might be riding in big front, big back or small front, small back.

check that your chain and/or cassette are not worn, but it sounds more likely to be a setting problem

[RiderX]

Another question while I am at it - is it normal/fine for the front derailuer to move to three different positions, despite only having two rings on the front? Is this a compatibility issue, or should this not be a concern?

 

You can adjust the limiter screw to prevent the derailleur from going into the 3rd (big ring) position. Look for the screw labeled (H) and turn this screw anti-clockwise (loosen) about half a turn initially. Keep making 1/4 - 1/8th turn adjustments doing this until it is not possible to shift into the bigring position anymore.

[Niner]

If it is shimano then it is the trimming click...have a look at how much the FD moves when you change....normally it the first click is small(trim), then the next one big(move the chain to big ring) and then DA has another small click while you are on the big ring(trim again)

 

Hope it helps.

 

WRT the gears 2 and 3, have your RD hanger checked, if all the other gears are fine then the hanger could be bend or the RD cage itself. That is if the barrel adjusting does not sort it.

[Azi]

Thanks guys,

 

Tankman,I have tried what you said - if I get the two problematic gears sorted out with the adjuster screw, then the biggest wheel ticks. If I get that sorted out, one or more of the others tick.

 

The front is not too much of an issue, as it doesn't move off the chainrings - the chain rubs against the inside of the FD which is sorted out by me 'changing' gear once more, similar to how Niner describes it above.

[Azi]

WRT the gears 2 and 3, have your RD hanger checked, if all the other gears are fine then the hanger could be bend or the RD cage itself. That is if the barrel adjusting does not sort it.

 

Will do this evening Niner - thanks for the assistance.

[Tankman]

Yup move on to the second phase the. If the gears continue to slipp after the barrel adjustments it is time to have the RD hanger alligned. LBS for this.

 

Doubt that it will be the chain itself cause it sounds fairy new from what you described.

 

A dirty cable housing can sometime also cause issues but I doubt once again that this is the case here

Edited July 12, 2011 by Tankman

[Tankman]

Thanks guys,

 

Tankman,I have tried what you said - if I get the two problematic gears sorted out with the adjuster screw, then the biggest wheel ticks. If I get that sorted out, one or more of the others tick.

 

 

Before going off to the bike shop, set it up again so it only skipps in the biggest gear. Then adjust the high limit screw on the RD, 1/8 adjustments again. Might be all that is needed. If all else fails ... LBS

[LeTurbo]

THere are some good Youtube videos on this: try

[SirHamilton]

If half your gears shift perfect and the other half not it is more than likely that your mech or mech hanger, more likely hanger, might be ever so slightly bent. This does not mean you need to try and hunt down a new hanger as you can straighten them but you need a tool to do so

 

 

 

Hope that helps