How much movement should there be on a normal 3×9 mtb setup? Only reason I ask is because I have noticed a bit of chain slap on the bottom of the drive side chain stays where it meets the BB on my Cotic Soul. When I think about it the chain does make a bit of a racket when out on the trails and it easily touches the chain stays when I move it by hand. Do I need to take a link out or is it fine? The chain had never jumped off the rings and doesn’t slip.

Trevor.

IIRC from the fitting instructions of Shimano mechs it used to be chain round big ring and large sprocket plus two links.

Not sure if this is still current.

this is what I go on: http://sheldonbrown.com/derailer-adjustment.html#chain