Need wheel experts please - non-Beretta question

jackattack193 · Post by **jackattack193** » Thu Apr 14, 2011 10:29 pm

I'd like to get a set of rims for my dad as gift for his '56 Chev Bel Air. The car doesn't have any mods - and the widest rims it looks like we can put on the "factory" set-up is a 15x8 with 4.75 backspacing.

I did a quick search - and it's hard to find a company that advertises backspacing, but all seem to mention offset.

Is there a way I can search a 15x8 with a specific offset that equals a 15x8 with 4.75 backspacing? As you can see, I have no knowledge in this area.

Barry · Post by **Barry** » Thu Apr 14, 2011 10:44 pm

Backspace=(.5*wheel width)+(offset)

Barry · Post by **Barry** » Thu Apr 14, 2011 10:47 pm

A 15x8 with 5-6mm positive offset will give you 4.75 backspace.

Barry · Post by **Barry** » Thu Apr 14, 2011 10:54 pm

http://www.rimsntires.com/specs.jsp

best site ever

woody90gtz · Post by **woody90gtz** » Fri Apr 15, 2011 8:53 am

Barry's got it. Offset is the best way to measure wheels, because when you change wheel widths if the offset is the same the tire still fits the same. Backspacing changes as wheel width changes and the way the wheel is centered in the wheel well is different.

For example, a 225/45/17 tire will fit the same on a 17x7/40 offset as it will a 17x8/40 offset. However, a 17x7/5.5 backspace wheel will not fit the tire the same as a 17x8/5.5" backspace, it will be 1/2" pushed out from the fender.

jackattack193 · Post by **jackattack193** » Sat Apr 16, 2011 9:17 am

Thnx for the help guys.....that website rocks Barry, nice call on that.

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