Chain Jumping with new cassette & Chain

B14er

I've had a Specialized Hardrock for 2 yrs now and from new the chain has always jumped when in 2nd to 4th gear on the middle front ring (only when under load). In the past I've managed to rectify the problem by lagging the chain in oil which has made it a bit more reliable but not perfect.

The bike's just been serviced and had the cassette, chain and middle ring replaced because I was told they were worn but to my annoyance the jumping chain issue is still there.

Any suggestions on a fix? Could it be the indexing on the shifter, bearing in mind that its happened from new?

I really don't want to resort to drowning the chain in oil again as I like to keep the drivetrain clean when possible...

blablablacksheep

i have a issue also with my rockhopper but i know its my middle ring/outer ring.

If you say that you have had following replaced

Chain
Cassette
Middle ring

Then it shouldnt be jumping under pressure, the gear index could be a issue so i suggest you check out Park Tool FAQ for working out the index of the rear gears.

Also make sure you using the correct gears for the middle ring, as in reality the middle ring cant go though all the gears without jumping on some, so try keep it within its range.

Do you have issues moving from middle ring to outer/large ring?

Also check if your jockey wheels are very very worn, as sometimes this can cause issues though rare.

peter413

blablablacksheep wrote:

Also make sure you using the correct gears for the middle ring, as in reality the middle ring cant go though all the gears without jumping on some, so try keep it within its range.

How can I use all my gears in my big ring on my dual ring setup and all my gears on my single ring setup

Check your mech hanger, if it's only skipping in certain gears it could be that which is causing it

B14er

Thanks for your replies.

I've fine tuned the barrel adjuster on the cable which seems to have helped, albeit moved the problem to gears I use less often.

Is there a way of adjusting the index of shifters (they're shimano SL-M360 if that means anything)? I've always assumed its a fixed setting for each type of shifter and can't see any way of adjusting it.

cooldad

Look on the Parktools website (link in Nicklouses sig) for how to index your gears.