I just bought a 2010 zesty 916 frame and built it up with 2×9 standard xt / xtr components. Had first ride out this morning. Geat bike but there there was a ridiculous amount of chain slap on rocky technical descents which I am hoping to cure with fitting a bionicon chain guide, and taking a few more links out the chain, but the whole way down the rough stuff, the rear mech was also clanking off the chainstay making actually quite worrying noises. It was banging like crazy. Any suggestions how to address this? I have wrapped the chain stay and seat stay with strips of inner tube as a stop-gap measure, but don’t care for the mech /frame collision issue.
Any ideas , suggestions from lapierre owners or mechanics would be really appreciated,

Cheers,
Colin

Is it a shadow mech? If not it’ll bang like a shit house door when the plagues in town.
IIRC the frames are designed around the shadow mech and with these sitting lower its not an issue.

Check chain length. Check main pivot on rear much is free moving. It’s quite common with Horst Link bikes. You may find a different gear works better. I tend to descend on the middle of the cassette and don’t suffer this too much. Using the big ring at the same time keeps the chain nice and tight. You might be able to adjust some of it out with the B tension screw.

Crag – Member
Is it a shadow mech? If not it’ll bang like a shit house door when the plagues in town.
IIRC the frames are designed around the shadow mech and with these sitting lower its not an issue.

Yep – needs to be shadow.

Magic- it’s not a shadow rear mech so will have to get one. Thanks for the help folks. Cheers!

Is your shock rebound set right ? Same thing happened to me recently with a new bike, added an extra click of rebound, sorted 😉