Small Bolt Pattern Tire Options (14in. steelies)

RustyRatRod · Nov 18, 2022

Dana67Dart said:
Agreed.

But unless you are putting 185 wide tires on a 12 inch wide wheel the tire is going to contact anything on the car long before the wheel.

A lot of semantics, just ask, that way your getting numbers your expecting.

I have 185 wide tires on the 13" wheels on my Valiant. I cannot see them physically fitting on a 12" wide wheel and if they did, the wheel would certainly be first to contact something.

SGlez10 · Nov 18, 2022

72bluNblu said:
There are a ton of ways to measure backspace the wrong way. There's only one way to do it right, which is the outside of the lip to the wheel mounting surface.

The lip of the rim is basically ~1/2” wide, which is the entire tire clearance you need to maintain to the rear springs. So messing it up and measuring to the inside of the lip makes a BIG difference. At one point I was running ~3/8” clearance from tire to my rear springs, so yeah, missing by a half inch would have meant an 1/8” of interference. That doesn’t work.

Rim width is measured inside to inside, (or where the beads mount), which is why rims are always ~1” wider outside lip to outside lip. Backspace is always outside lip to WMS. And if you really want some confusion, offset is always the distance from the WMS to the centerline of the rim.

That’s why a 15x8” with a 4.5” backspace is a zero offset rim. A 15x8” is 9” wide outside to outside, so the backspace outside to WMS is 4.5”, and that’s the centerline.

This is all great information and I appreciate it. Would you happen to have this information with visuals present? I tried googling but they’re not all the same so it’s hard to know which is correct.

72bluNblu · Nov 18, 2022

SGlez10 said:
This is all great information and I appreciate it. Would you happen to have this information with visuals present? I tried googling but they’re not all the same so it’s hard to know which is correct.

Sure, here’s a diagram