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Skipping drivetrain
 

[Closed] Skipping drivetrain

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[#8385623]

I have just replaced the Chain, Cassette and chainring on my road bike. I knew the chain was stretched ages ago and was short of funds so rather than shelling out then for a new cassette and chain I left it for ages (2 years of commuting) and have only just replaced the lot over the weekend.

This morning the chain jumps when fist applying any power. Could it be my jockey wheels have deformed teeth from the old baggie chain? The gears shift OK (a smidgen slow down shifting so probably need a bit of tweaking) and once I'm pedalling along everything seems OK its just after freewheeling or accelerating from a stand still the chain clatters around until settling down.


 
Posted : 06/03/2017 11:52 am
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chain the right length?

Freewheel working okay?

Chain the correct way through the jockey wheels?


 
Posted : 06/03/2017 12:29 pm
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did you try indexing your rear gears again after fitting the new goods? I'd start there if you haven't. Turn the barrel adjuster all the way in and the one on the mech if there is one. Undo the cable and make sure it runs free in the outers all the way to the shifter. Set the upper and lower limits again and then index as usual. One click on the shifter equals gear down, if it doesn't turn the barrel adjuster quarter turn till it does, all the way through all the gears.
It could also be a bent mech hanger.
It could also be worn jockey wheels, although not so much. Do they look worn?


 
Posted : 06/03/2017 12:30 pm
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Once you've tried the sugestions above, and if you still find you have issues, a common problem is a bent mech hanger. If this is the case even if you replace the entire gearset and follow the indexing instructions to the letter it still won't shift properly.

You can get the hanger realigned in a bike shop or buy a hanger realignment tool like these and do it yourself:

X- Tools £31.99 - http://www.chainreactioncycles.com/x-tools-pro-gear-hanger-alignment-tool/rp-prod122319

Park Tool £54.99 - http://www.chainreactioncycles.com/park-tool-derailleur-hanger-alignment-gauge-2-2/rp-prod149800

Video on how to use them: https://www.youtube.com/watch?v=C0oOwyqubh4

Bent mech hangers are quite common and occur even with brand new out of the box bikes. Some of the better shops will automatically check gear hangers when they assemble all new bikes for customers.


 
Posted : 06/03/2017 1:00 pm
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Cheers for the suggestions. I am pretty sure the mech hanger and freewheel are both OK as the issue has only started after replacing said components. The chain is definitely routed correctly and the right length.

I had to reindex the gears so I am going to work on the basis I haven't done it very well (seemed perfect in the stand but its slow to down shift on the road so its probably all linked).


 
Posted : 06/03/2017 1:26 pm
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If you're using a quick link is it fully closed, if it's not all the way home that will cause skipping.


 
Posted : 06/03/2017 1:47 pm
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Int he stand and under load never seem to be the same.

Quicklink is a good shout also. Been there, done that!


 
Posted : 06/03/2017 2:01 pm
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is the wheel in straight? i have lost count of the times this has happened to me.
after that just re-index again.
including high and low limits.


 
Posted : 06/03/2017 3:06 pm