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jumping cogs

Posted: 7 Jun 2009, 9:39pm
by blazingsaddles
My chain is a little erratic when I put some load on the pedalling. It happens more from the middle to smaller cogs on the cassette. It can jump up or down a gear or two and happens more going uphill.

I'm running a deore lx rear mech (top normal) with lx cassette bar end shifters and deore chainset and front mech. All fairly new.

Anybody any ideas please?


Re: jumping cogs

Posted: 7 Jun 2009, 11:48pm
by tb
Hi there,

my first thought was that you have a worn cassette, which would cause the chain to 'jump' across the rear cogs, but you sat that it is fairly new kit so this should'nt be a problem.
Given that your bike has a fairly new cassette / chainset & derailleurs I would suggest that you need to look at the adjustment of the levers / cables & derailleurs which can easily affect the alignment of the chain on the rear casstte.

Have a look at Sheldon Browns webite for tips on setting up transmissions.


Re: jumping cogs

Posted: 8 Jun 2009, 6:50am
by blazingsaddles
Looks like a worn out cassette. Can certainly see hooks. Thats very premature. Its a 9 speed LX. The whole bike has only done about 1000m from new. All road miles.

Back to supplier.

Any ideas on better replacements?


Re: jumping cogs

Posted: 8 Jun 2009, 10:25am
by meic
These Hyperglide cassettes look as if they are hooked when they are new. Dont be too quick to condemn the cassette, I am not saying it isnt the cassette but I for one can not tell by looking.
Also I have shimanos cheaper cassettes which are still good after 4000 miles.

Re: jumping cogs

Posted: 8 Jun 2009, 11:32am
by NUKe
If everything is relatively new and well oiled. Check gear change cables. are not frayed or sticking

Re: jumping cogs

Posted: 8 Jun 2009, 11:55am
by Jack
Exactly the same happened to me yesterday. I found the cable close to the rear changer was the problem (I think I'd snagged it with a pannier and it was slightly bent from normal position.

Re: jumping cogs

Posted: 8 Jun 2009, 6:30pm
by blazingsaddles
I reckon you fellas are right. The cassette is probably ok.

Thinking about it The gears cables are now a little more taught since ive put the bar end shifters into moustache bars. Also I use a caradice bar bag and that touches both cables and pushes them out a little (only since the tache bars have been fitted).

Got to try it without the bar bag and then perhaps put a longer cable with a longer sheath from the bar ends to the down tube.

Any other ideas appreciated but thanks so far.