I've got an "85 fxwg....Thinking of bumping up the rear tire size from a 130 width to a 140 (Dunlop) . Belt drive Evo in a 4 spd. swingarm frame.....anybody done this ? looks like there's about 1/2 " clearance between the belt & widest point of the 130 tire.........Thanks in advance for any info !

 

Assuming your rim is wide enough for the 140 tire, you should be able to do it. A half inch = 12.7mm. Your proposed tire size is 10mm wider (5mm each side of center).

12.7 - 5.0 = 7.7mm clearance (a little over a quarter of an inch)

 

Thanks a lot Lucky ! Just what I needed !!

 

Can't speak for a WG, but I had a 140 in my FLHS. I don't recall there being as much spare room as you mention, I had to trim my belt guard to get the wider tyre in. There was 3/16" clearance and I used an allen key as a guage to check clearance, when adjusting the belt!

The widest tyre you can fit on a 3" rim is 150 (at least according to Avon). I have one now, with a narrow belt. Fitted width is 153mm. My Avon Venom 140 was 139mm wide. I never measured a stock tyre!