What is wheel backspace?

Whats our backspace clearance? Something close to 4.75…
I have no idea what it is.

Never heard of that term, where did you get it from?

Closest thing i can think of is OFFSET.

Hey,
I was talking to a guy about buying some wheels…different than the mainstream crap, and he tells me he has the set i am interested in, and gives me these specs:
4x100
15x6.5, with a 4.75" backspace…

Is this the offset? I thought it was, but have no idea what our stock offset is. Will these fit?
Thanks in advance,
Scott

Just ask hiim what the offset is…thats all the info you’ll need to buy rims.

Offset should be around +45 or so.

Any chance you could explain what that number means? I am pretty clue-less when it comes to that kind of detail. I would like to know more about it…thanks
Scott

Well as I understand it, it is how far the wheel sticks out from the hub or something.

ie :- A +35 offset wheel will stick out more than a +45 offset wheel. The more it sticks out, the higher chances of rubbing.

when you say +35, +45…what unit are we talking? millimeters? 45mm would be about 1.7 inches…am I right? Does this sound right? And if so…what the heck is that 4.75" all about that he gave me?

I will do a little more research…but if anyone has a clue…i would appreciate it greatly.

Thanks,
Scott

I dont think it is in “mm” units. I think its just a unit of it’s own or something. A universally understood convention !

hey, take a look at this website…
http://home1.gte.net/nugentmd/backspace.htm
Do you know what the stock spec is for our cars here? What about a nominal spec…will that 4.75" width be good/bad…I am kinda at a loss here, since I really would like these rims, but will be needing to drive a few hours to get them. I dont want to end up wasting my time.

Thanks
Scott

I also found this…it would be helpful, but I am not sure where to find all the specs for our cars on this stuff. I am sure someone had to figure this stuff out before buying wheels, no? I suppose I could go get out my ruler and check my stock steelies.

http://www.rsracing.com/tech-wheel.html#caliper

Scooter

From what those websites say, sounds like backspace is offset.
Stock is +45

So i dont need to measuring at least. Do you know what offsets will fit with 6 inch wide wheels? I want to make sure that A) Its not going to rub B) its going to be safe and C) The tires wont stick out of the wheel-wells.

The diameter of the rim is 6", and i would guess the offset to be in the high 30’s according to that site I just posted.
Thanks,
Scott

i dont think you can put 6" diameter rims on our cars
perhaps you mean 6" width

Offset is measured from the centerline of the wheel to the surface that the hub will mount to. Offset away from the car is positive, towards the car is negative. Backspace is the measurement from the inside flange of the wheel to the surface where the hub will contact the mounting “plate” of the wheel. Offset is measured in millimetres. Now you know

:read:

thanks guys…that was helpful…and yes, i meant 6 inch width. the wheels i found have a 35mm offset…and they are indeed 6 inches wide…that sends the wheel outward from the hub, correct…and only by a tiny amount if i calculated correctly. I am gonna be pissed when i find out that they arent even original to the club…im sure someone has had them on our cars before…hope not though.
Thanks again
Scott

ya i think ‘backspace’ is the same as offset. 45mm = 4.5cm, so maybe oldschoolers measure offset as backspace in cm.