New Chain Jumping on newish Cassette....

Lig

Hi all,

I have a Campag record cassette that is about 6 months old and has had moderate use (always cleaned after every ride)...I bought a new chain and It works fine on all cogs except the 21T (12-25), anyone any ideas why this is happening and if I give it some time will it 'bed in'?? I really dont want to shell out another £170 on a new cassette???!!

Cheers,
Lig.

gsk82

i know very little about chains but have been looking up a bit online recently about gear indexing, i intend to change my chainrings and chain next weekend. it sounds to me like the cable tension needs adjusting. there's videos on youtube about gear indexing that mention it

Lig

Hi gsk and thanks for your response...

Its deffo not the indexing as it works fine in all other gears and in this one when on the flat, it is just when I put pressure up hill on the 21 that it starts to jump...

Cheers,
Lig.

ricktabor1

I had a problem like this once and, when i looked really closely, one of the pins/rivets in the chain was sticking out ever so slightly. This meant that when the chain was in a certain gear (at one certain angle) the rivet was hitting the next sprocket slightly and maling the chain jump. It was my fault cos i hadn't put the connecting rivet in flush.

This probably isn't what's happened to yours but it's worth a look.

Ollieda

stupid question but..........Have you lubed it up?

Always worth just checking as a lack can cause loads of problems

neeb

When you say it is jumping do you mean it its jumping off that sprocket onto another one, or that it is skipping, as happens with a very worn chain/sprockets?

If it is just jumping off the sprocket to a higher or lower one, one thing to check (apart from the obvious things like that the outer cables are the right length and that the cable is moving smoothly in them, etc) is that you have fixed the cable to the rear derailleur correctly. The illustration in the instructions isn't very helpful, but the cable needs to be fixed so that it is in the groove in the little plate / washer below the nut. It shouldn't be routed around either of the two little flanges that stick out from the washer. This makes a big difference to the efficiency of the shifting in 11sp, as I discovered myself. Another thing I read about was that some of the early 2009 11sp cassettes required an extra, very thin spacer between a couple of the larger cogs. If your cassette has one black plastic spacer that is a different shape (with partially sloped edges) then you have the up-to-date one and should be fine however.

MRadd

I had this issue a week ago. Turned out to be nothing more than a stiff link!

Lig

Cheers guys,

It skips like a worn chain/sprocket, but like i said its a new chain and a 6 month old cassette. Its fine on my turbo, and I only noticed it when I took the bike out on the road and it only happens up hill with force....

I will check all that you have suggested and report back...

Cheers,
Lig.

giant_man

Does sound like an indexing problem, probably only needs fine adjustment ...

Velonutter

I had this exact problem on the 23T on a 25/12 problem with a Chorus Cassette that had done only a few hundred miles and a new Record chain, I was told to let the two bed in and 100 miles later it worked.

Allow the two top bed in and it should be fine.

dennisn

giant mancp wrote:

Does sound like an indexing problem, probably only needs fine adjustment ...

+1.... that gets my vote as the first thing to check out.

neeb

dennisn wrote:

giant mancp wrote:

Does sound like an indexing problem, probably only needs fine adjustment ...

+1.... that gets my vote as the first thing to check out.

+2, on second thoughts. Presumably the OP has already tried fiddling with the indexing, but modern gears actually work so well that you can set the adjustment quite far out and it'll sometimes still shift almost perfectly... until you do something like try to shift under pressure on a particular sprocket...

Lig

Thanks again guys,

When I get a chance to look, I will let you know. But I dont see why the indexing would change with just chaning a chain?!?!?!

I am hoping 'Slow N Old' is right and it just needs to bed in, but I will check the indexing as its been on my turbo for the last 3 months or so and all works fine on here..like I say it was just when I took it out for a quick spin in the dry the other day and it started skipping on the 21....

I will report back... should have some time to check this weekend..weather permitting...

Cheers all...

Lig.

Lucky Luke

What was the answer then ?

Lucky Luke

What was the answer then ?

Lig

Hi chaps,

Bit of a strange result this....It deffo wasnt indexing as I bought a new cassette and this worked fine.

I then put the old cassette on another bike and this seems to work fine also. I guess this chain (which was replaced at the same time as the other) will have had a bit more use, so I think it was just a new chain older cassette mismatch??

Lig.

ADIHEAD

Very common problem. The chain basically wears the cassette as it wears out. Make sure you swap this chain before it gets to .75 worn and you may save the cassette. That's the rule of thumb but you never know till you put the new chain on! In theory the second chain would then wear out slightly faster than the first due to the slight wear on the cassette and so on. Most of the people I ride with reckon you can just about get 3 chains per cassette doing it this way (I've not tried more than 2 as have had a few groupset swaps lately!) Get a chain checker if you've not done so already.