Chain slip under tension

[Fifelad]

New chain fitted at LBS cassette left as it is still in good nick. Slipping when tension applied (standing up on hills etc) .I am guessing a new cassette may have to be the investable solution, but I am going to tension the chain using the adjustment screw on the derallier and see if that works, or shortening of the chain... Opinions please...

 

[Rickshaw Phil]

It sounds to me like the cassette isn't in as good a condition as it looks. If it is only slipping occasionally and only under heavy load, it is possible that as the chain beds in it will sort itself out (the freewheel currently fitted to my knockabout bike was like this), but I wouldn't put any guarantees on this at all.

Replacing the cassette would be the favoured solution.

 

[Fifelad]

Thought so. I tightend the chain by adjusting the tension screw on the deraillier and it has improved significantly. No slip on the big ring, but now there is slip on the small ring, but only when it is on the third largest cog on the rear, which is the most commonly used cog.Visually it's not bad at all but as you say probably significant enough for not good enough fit between cassette and chain. I do know that normally a new chain is often accompanied by a new cassette, but I try to get two chains to every one cassette.This is my winter bike that was second hand so no idea how long the cassette was on for.

 

[Damaged Hero]

I am having the same problem with my Hybrid,I replaced a worn Shimano 9 Speed chain for a KMC-X9L.It worked fine whilst on the work stand but out on the road when I stand up to give it some it slips,but it's not changing gear as far as I can tell it just slips.

I am now looking at replacing the cassette,but on the Shimano website it lists Super Narrow 9 Speed HG chains as the correct/suggested replacement chain, Have I made a mistake in buying the KMC chain ?.

 

[Rickshaw Phil]

, Have I made a mistake in buying the KMC chain ?.

No. KMC chains are very good quality and fully compatible with Shimano components (I understand that many Shimano branded chains are made for them by KMC).

I'm afraid that, as above, it sounds like the cassette has past its best.