So, Friday night I fitted a new KMC chain. Cassette and Chainset are XT M770 – both are used but neither are particularly worn.

The changing of the chain was mainly experiement, heard good things about the KMCX chains (had a 971 on there previously, which was fine).

Tuned up in the stand, quick skeg up and down the drive, no problems.

Arrive at Dalby – Instant, chronic, un-avoidable chainsuck in the small ring. Damm nearly killed me as I had to do the lap in a 32 (I'm a spinner not a grinder!).

Problem is – its got me stumped.

Chainring looks fine – its not brand new but its not knackers, no burrs or bent teeth etc. Chain is brand new. Works faultlessly on other Chainrings and all the way up and down the block.

But as soon as you change into the 22t, instantly wraps round and jams up. Also tried re-settling the front mech and that seems fine too.

Ideas?

chain ring is worn enough to catch up on new chain.

Try putting old one back on and see if problem persists?

chain ring is worn enough to catch up on new chain.

odds on that's the answer. Exactly how do you define 'not particularly worn'?
Was the old chain worn out? if so then chances are the cassette and chainrings are too

http://www.fagan.co.za/Bikes/Csuck/

"You really want to suffer from ChainSuck ?

Use a NEW chain with your WORN chain-ring !!
WHY ? Read on …"

So that'll be a new granny ring when the bike goes in on Thu, after less than 700 miles. Ar*e :-/

Must try & sneak a singlespeed winter hack past the wife.

Andy