I am going to change my drive belt from the stock 1.5" wide belt to a narrower belt to get a wider tire on. Does anyone make a 1" wide 70T pulley? I can't seem to find one.
You don't mention what yr./model you want to do this to. Swing arm width (inside) also needs to be checked to see if there is enough room for a wider tire, as well as belt guard.
Its going on a 1986 Softail but I run a second generation rear swingarm, but that really doesn't matter, the rear pulleys are almost all interchangeable on big twin models. And a half inch on one side gives room for an inch wider tire. Also the new belts are a lot stronger than they were when they had to make them really wide.