1. CM360

    CM360 Well-Known Member

    Messages:
    261
    Likes Received:
    6
    Joined:
    Sep 18, 2011
    Its one of those deals where if you get it right, your good and if not you're trying to sell a brand new set of wheels because they don't fit. I need to put a 9" slick on my Aspen. 8" rim but the backspace that I calculated is off. Measured and thought that a 4 1/2" backspace would be right. Borrowed a Weld wheel from a friend and its right on the leaf spring and inner tub. Anyone solve this problem?
     
  2. Aspen500

    Aspen500 Well-Known Member

    Messages:
    4,399
    Likes Received:
    1284
    Joined:
    Feb 14, 2015
    Location:
    Rib Mountain (Wausau) WI
    Best way is get a Percy's WheelRite deal. It's cheaper than buying wheel/tire that won't fit. I bought one and used it on my car and it made size and backspacing easy to figure out with no hoping it's right. To form the wire that simulated the tire, Summit lists all the dimensions of the tires (section width, tread width, sidewall, etc) or also the tire manufacturers site would have it also.

    Percy's WheelRite Wheel and Tire Fitment Tools 01201

    percys.jpg
     
  3. Oldiron440

    Oldiron440 Well-Known Member

    Messages:
    2,442
    Likes Received:
    471
    Joined:
    Apr 25, 2017
    Location:
    Iowa
    I have my springs pulled in and I'm using mopar offset shackles, I use a 15x10 weld 4.5 back space and the 30x10.5 w are at the springs, now if I use a Centerline 15x10 4.5 back space and I gain .5 inch per side. Different wheel Co. measure offsets differently, some use the bead seat ( the one I prefer) and some use the widest lip of the wheel.
     
  4. CM360

    CM360 Well-Known Member

    Messages:
    261
    Likes Received:
    6
    Joined:
    Sep 18, 2011
    I measured with the Percy gadget and came up with 4.5 BS. Kissing the leaf spring and inside sheet metal. Guess that 4" should work. Don't need to make 2 mistakes.