KTM Area Comp 2016 (Hardtail)
Bike is set up from new with 10 Speed (11-36) XT rear mech and triple front chain ring (deore 22/30/40)
At the weekend I put on a new Xt rear mech, new cable and brand new 10 speed shimano HG-X mountain bike chain.
Gears working perfectly.... except when in hill climbing. When in 22T and 36T the chain makes a "clunk" noise on the front chain set, once every rotation. Easy I though.. got to be a broken tooth or damage. Took 22T chain ring off and its perfect, no damage and not bent etc
totally stumped... it is a "dyna system" but chain says "dyna system compatible"
can rule out
- chain length is good. It made this noise and I first though I had cut the chain too short, so ordered another and cut it a little longer - same noise
- Not rear mech as perfect in other gears.
I use a power link connection but it's not that making the clunk. Not bottom bracket or crank related. Chain is defintely a 10 speed.
Going to order a new 22T and try that ???
Once every rotation, and you've ruled out the chain... Got to be either the cassette or the rear mech surely? Fiddled with the mech limit screws, chain could be trying to jump about if it's not happy where it is?
Sounds like limit screws to me if it's indexing right but playing up in largest sprocket.
will try again with limit screws but pretty sure they are set fine. The "clunk" noise is coming from the 22T chain ring not the rear mech.
thanks
possible that the middle c/ring has a slightly bent tooth and it's catching the chain? when it clunks does the rear mech also move slightly?
good idea, I will check. Middle ring runs smoothly but is a possibility. When it clunks the mech does not move or make any noise.
I'm stumped as if it was rear end then the usual suspects would apply (limit screws, b-tension etc but all running fine)
I tracked a similar sounding klunk down to a seizing jockey wheel. Sram mech though.
...the chain makes a "clunk" noise on the front chain set, once every rotation.
Once every rotation of what exactly: Chain? Cranks? Wheel?
Chain ring bolts tight?
Any play in BB?
check the chainring bolts
Spin it slowly and look at every contact point when it happens rings, mech etc. Is the magic link pulled closed properly? Stiff link? Something catching?
Just got to be methodical
front mech cable clipping the crank?
"clunks" every turn of the 22T chain ring, noise comes from this ring at the front of the bike at the chain rings. Chain ring bolts all tight and no play or damage. No issues with BB and still fairly new. Powerlink is pulled tight and fine in other gears.
will keep plugging away. Thanks for the replies it has thrown a few ideas out there for me to double check again.
Is it actually the cassette?
Its not the crank arm catching on on something is it?
Stiff chain link?
One bent/damaged tooth?
Check your pedal bearings too - pressure in low gear = bearings shifting if worn?
I had a new chain on my commuter that gave me grief in certain combinations, tried all manner of things, different cassette, indexing etc.
Gave up and got a new chain in the end, and that sorted it. Must have had a bad link from the factory.
Just discovered: when cycling along in hill climbing If I push the front mech a fraction so it slightly rubs the chain the noise stops. Makes me think the chain alignment coming into the chain rings is not good ?
Chain catching the front mech cage at one end. Moving it slightly is eliminating the noise at that end as it no longer contacts?
Going to remove cable tension in front mech and test...
I would just try tuning ir out using barrel adjusters or limit screw and see if that makes any difference.