Hello. I've been looking arond for a set of rims for the cutlass supreme. Problem is, I dont know anything about rims.
I do know I am looking fo a set thats 15x8, what I do not know is what my bolt pattern is, and whats the offset and the backspace??

Danke for my answer.

Rims are one of three basic sections of a wheel. They are, rims, centers and hubs. One would not get very far, using only rims on a car.

Using a bicycle wheel as an example, it can be easily broken down to those (rim, spokes, and hub) sections. In common automotive applications, the hub might not be attached to it, but it's still part of the wheel.


I would question whether that wheel with matching tire would fit on your G body without modifications.


For your G body? 4¾" on 5.


As a spec, the backspace is the horizontal distance between the inner rim, and the mounting surface of the hub. That measurement can be refered to, as offset, or backspace.

If you are asking about a specific wheel, that distance will vary by manufacturer and the individual wheel design.

Norm

Hi Norm, all,



This is semantics, but I have always known bolt patterns to be in the number of bolts on the spacing. For instance, that would make the G body 5 on 4 3/4''.

Not that it makes a difference, or applies to this thread, but is there a standard of reference when it comes to this, or is it regional?

Andrew

I'm not sure but that's the way I've always seen it too, andrewk. Not being too technical or anything...

TOC Admin
Brando

Thought about that, and sent it anyway, just to see if you were awake.

5 lugs, on a 4¾" Bolt circle, is the way I've always heard it.

The following applies to me only:
5 on 4½, 5 on 4¾" and 5 on 5" is what I've always heard. I have always called them, small GM, big GM, Ford, Mopar, etc. There are few who share my interest in vintage tin, that do not know my meaning. You could call it a "generation" thing, if I was that old.

I know the standard Ford pattern on my trailer is smaller than the small GM used on my Chevs, Cutlasses and G body, but have trouble keeping track of the numbers. To make sure I used the correct number (4½) I "Googled" for a wheel dealer and "cut and pasted" the number given.

Knew it was wrong, but sent it anyway ........ Wait: It can't be wrong, because it's on the internet.



My Cragars are in my basement. They will go on my '65 or my '70, when I decide which I will sell.

Norm

What's too big?? What would get in the way? What kind of modification?

What size would you suggest? (keeping in mind I'll be using them with the 455)

Did I say anything about "too big"?


Did I say anything would?


Did I say any would be needed?


An 8" wheel should have a tire with 8" of tread on the ground. As long as the tire is correctly matched to the wheel, it's your choice, not mine.


455 would be a subject for a different thread.


If I wanted to change to larger wheels/tires, I would use a simple straight edge and a measuring tape to find out how much air there is between the tire and anything it could rub against. The air gaps, and the difference between them, would show how much space was there, and what backspace change might be needed to center the tire in the wheelhousing.

Allowing for up/down wheel travel, I'd subtract 1½ to 2" from the results, then find the tire with the section width that fits in the space, when mounted on the desired wheel.

BTW: Re Googled it, and the bolt pattern info came from here. They're in Arkansas, so I don't know whether to call it a "regional thing", or not.

Norm