.060 shim behind spider on m1000

[doudea]

I just got a set of jaws twin pipes for my 2007 m1000. The instructions are calling for a .060 shim to be added behind the spider. Im unclear as to what this is going to do or accomplish, was wondering if anyone could explain why and what effect this will have? Thanks!

 

[winter brew]

Probably to reduce belt/sheave clearance....should be about .020", the Cats have been notorious for too much clearance, my '06 had over .080" from the factory, head to shim down to .020......which would be about right if they are adding .060".
Makes for much better bottom end!

 

[cooldown]

I was just talking to a tech guy at dalton today mine is a 08 1000c/f he told me to add a 60thou shim to the already 2-60thou and 1-30 thou the reason it will tuck the weight behind the roller more give you a lower engagement he said it will decrease belt burn at low rpm.I am going to try nothing to loose.