I was wondering if there is a height adjustable aftermarket chainguide for the rear? My original has so deep worn grooves that it is grinding the chainplates left and right and I had to take it off for right now. The reason why I would like one that is adjustable is because I am thinking to go to a 50 in the rear. For the 48 I am on right now it looks like the original chainguide sits already to high. Thanks for any input Det PS: this question is for a XR650"L"