9 spd Aviotek Cassette & KMC Chain 'jump' problems

5milestogo

Hi,

Have just replaced an old 9 speed DA cassette with an Marchisio Aviotek 13/28. Chain was changed to a KMC 9 spd but for 2 days I was using an Ambrosio 9 spd chain as the KMC's had not arrived.

Since I stuck the KMC on it has started to 'jump' when in the smallest chainring / small sprocket but I can't figure out why? :?:

I have changed the position of the sprocket as the smallest doesn't generally have the alignment spline but still no joy.

I realise that some may say why use that gear but its ideal for an easy ride and nevertheless its there to be used.

Any thoughts appreciated?
Shall I have another go (4th time) at realigning the sprocket.
Do I go back to the Ambrosio chain (what are peoples experiences of quality here) or stick with KMC?

Grateful for any guidance. Cheers

mercsport

Dunno.

Have you tooled about with your limit stops on the rear mech ?

Or / and , slacken / tighten rear mech' cable at cable adjuster on down-tube ?

amaferanga

There are good reasons for not using that gear and there will be a gear that gives a much better straighter chain with a very similar ratio.

Maybe the chain actually catching on the larger front chainring? And did you match the length of the new chain?

5milestogo

cheers, checked / rechecked limits & cables and no cigar!

That leaves me to check front chainring this w'end & take a look at the chain - lenght was fine when put on but maybe width an issue although would have thought not as Avoiteks should be generally 'universally' compatible esp with KMC chains - Ambrosio 9sp chains on the other hand seem less popular so would think they would have the problem. Will update as and when with WIP

saladfunky

Did you resolve the kmc chain jumping issue. I have recently fitted a 10 speed one to shimano 105 cassette and it jumped badly but is gradually improving after 50 miles or so but still jumps on certain gears, so I am replacing the cassette. Today I put a new kmc 9 speed on my mtb and that is jumping in the same way on pretty much all gears. Hope it will just settle down?????