So, I'm installing a pair of recently powder coated stock mags. Prior to having the dealer mount and balance a set of new Avon Cobras (stock sizes), I installed fresh rotors and an aftermarket rear pulley. I got the pulley from J&P Cycle, and it's clearly listed as fitting my bike. Once installed, the drive belt rubs the rear tire badly. I ruled out any problem with the axle shims or wheel alignment. It really seems that the pulley sits too close to the wheel. In the attached picture, you can see that the belt now sits all the way inboard on the front pulley, and it used to sit all the way outboard. The shiny part of the pulley is clearly where the belt used to sit. It now sits on the part that is black and grimy looking. I tried loosening things a little bit and pushing the belt outboard on the front pulley, but after one revolution of the wheel it was back all the way inboard, rubbing badly against the tire. I thought about installing a thick washer behind each bolt between the pulley and the wheel, but I don't think it would locate properly concentrically. I also just held a straight edge across the tire, and the pulley definitely sits within the edge of the tire. Granted, the Avon 150 may be a touch wider than the original Dunlop 150, but I've heard of people running a 160 rear without problems. I think the fact that the belt no longer sits on the same portion of the front pulley isolates the issue to the rear pulley.


Here is the pulley that I have: http://www.jpcycles.com/product/175-...&totalResult=1#


Am I right? Does this pulley simply not fit, or am I missing something stupid?

 

They make pulley spacers, if you had that pulley powder coated as well, then that'd be cheaper than a whole new pulley

 

Yup, move the pulley out .125" and your problems are solved. You can see in your pic that the front pulley is worn/shiny on the left side. That is where it should run.

 

Okay, got it. Obviously using a spacer makes more sense than trying a whole new pulley, thanks for pointing that out!


Sometimes frustration obscures things a little...


I'll measure from a straight edge across the face of the tire to make sure I'm ordering the right thickness, and then I guess I'll have the whole thing balanced again.


Thanks again!

 

No worries man, that's what is great about the forum, quick easy ideas

 

I couldn't agree more! Thanks again!

 

As stated, get a pulley spacer. Dont use washers, a pulley spacer will have a lip to align it in the hub. http://vulcanworks.net/Pulley-Spacer...0-p-1-c-2.html

I've been running one in combination with a sportster 68t pulley for over a year without issue.

 

Thank you for the link. Their selection and pricing are much better than most of the big online retailers... Order has been placed!

 

FWIW...Spacers thinner than 3/16" won't have a locating "lip"

...because you can't

 

Okay, I ordered two spacers from Vulcan Engineering (very good service and pricing, btw), a 1/4" and a 5/16". Here is the 5/16" installed... You can see that the belt still doesn't sit as far outboard on the front pulley as it did originally, although the tire rotates freely without belt interference (with no weight on the rear tire). Right now I have just over 3/16" between the belt and the edge of the tire. This seems too close to me... I'm worried that when loaded and warm and cornering it may make contact. Does it seem like I should try a 3/8" spacer or even a 7/16", or am I worrying about nothing?


Thanks again!