Wheel offset
Thread Starter
Melting Slicks
Joined: Jul 2003
Posts: 3,482
Likes: 864
From: Saratoga Springs NY
2024 C4 of the Year Finalist - Modified
2022 C4 of the Year Finalist - Modified
Wheel offset
OK , it kills me to ask this question.What is offset, and why do i only hear of it when people talk about Corvette wheels??? I am building a street /custom out of an 88.I want the 17x9.5 in the front ,like it is now, but the back i want 18x11 , like a zr1.But the problem is that i dont want the majority of the rim to be hidden in the wheel well.I want the look of the rears at least to stick out a few (maybe 2?) inches so the rim looks evil..The stock zr1 dosent really look like it houses 315 tires..Anyone that can help with this-great!!! Anyone with aftermarket rims like i desrcibed that can post pics, or link to pics-even better!!!! Thanks again..Brian :cheers:
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: Wheel offset (FostersPerformance)
offset... hmmm....
in the old days, it was called "backspacing".
It is a metric measure, in millimeters, that measures how far from the wheels center line the hub is located.
Backspacing was measured from the inside of the rim, back, to the hub.
In this situation, it is measured from the center of the wheel, looking at the "tread" surface.
I hope this makes sense.
for more info, check the Tire Rack
[Modified by bogus, 3:51 PM 7/16/2003]
in the old days, it was called "backspacing".
It is a metric measure, in millimeters, that measures how far from the wheels center line the hub is located.
Backspacing was measured from the inside of the rim, back, to the hub.
In this situation, it is measured from the center of the wheel, looking at the "tread" surface.
I hope this makes sense.
for more info, check the Tire Rack
[Modified by bogus, 3:51 PM 7/16/2003]
Thread Starter
Melting Slicks
Joined: Jul 2003
Posts: 3,482
Likes: 864
From: Saratoga Springs NY
2024 C4 of the Year Finalist - Modified
2022 C4 of the Year Finalist - Modified
Re: Wheel offset (bogus)
Ahh, thats the term im used to..So if you had 56mm offset, and wanted a deeper looking rim, you would numaricly go higher then??? I understand now.
Team Owner
Joined: Sep 2001
Posts: 62,067
Likes: 1,723
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Wheel offset (FostersPerformance)
I think the backspacing on the regular rims on 88 is 56mm, the ZR1 is a little different, its rear bumper is wider than the regular corvette and its side paneling is shaped a little differently to accomodate that big rear wheel.
Although i cant remember the offset on the ZR1 rears' 17x11 rims.
If you left a stock rear bumper on, and put on a ZR1 rim, it would probably stick out at least an inch, not sit too far in.
Although i cant remember the offset on the ZR1 rears' 17x11 rims.
If you left a stock rear bumper on, and put on a ZR1 rim, it would probably stick out at least an inch, not sit too far in.
Melting Slicks
Joined: Oct 1999
Posts: 2,501
Likes: 177
From: Houston, Texas FEAR THE BONES
2023 C5 of the Year Finalist - Modified
Re: Wheel offset (vader86)
- Stock '88-'96 Vettes have 56mm offset for the 9.5" rim.
- Stock ZR-1 rears (17x11) have 36mm offset, but the rear on the ZR-1 is 3" wider than standard Corvettes.
- If you install "true" ZR-1 rims on your '88, they will stick out approx. 1.5" from the top of the fenders.
- If you install Grand Sport 17x11 rims, which have 50mm offset, they will *barely* stick out from the fenders. A lot of people add the Grand Sport fender flares to their cars for this reason (to cover the rear tires).
I have seen a few Vettes with real ZR-1 rims on the rear, and I personally do not like the look -- looks trashy. Go with the Grand Sport 17x11 rims... :seeya
- Stock ZR-1 rears (17x11) have 36mm offset, but the rear on the ZR-1 is 3" wider than standard Corvettes.
- If you install "true" ZR-1 rims on your '88, they will stick out approx. 1.5" from the top of the fenders.
- If you install Grand Sport 17x11 rims, which have 50mm offset, they will *barely* stick out from the fenders. A lot of people add the Grand Sport fender flares to their cars for this reason (to cover the rear tires).
I have seen a few Vettes with real ZR-1 rims on the rear, and I personally do not like the look -- looks trashy. Go with the Grand Sport 17x11 rims... :seeya
Thread Starter
Melting Slicks
Joined: Jul 2003
Posts: 3,482
Likes: 864
From: Saratoga Springs NY
2024 C4 of the Year Finalist - Modified
2022 C4 of the Year Finalist - Modified
Re: Wheel offset (FostersPerformance)
Ok im still a little confused.If a zr1 rim has 36 mm offset, why does it stick out 1.5"??? If offset is mounting surface to outside of rim, wouldnt numaricly higher #'s cause the rim to stick out of the wheel well further??
Team Owner
Joined: Sep 2001
Posts: 62,067
Likes: 1,723
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Wheel offset (FostersPerformance)
Ok im still a little confused.If a zr1 rim has 36 mm offset, why does it stick out 1.5"??? If offset is mounting surface to outside of rim, wouldnt numaricly higher #'s cause the rim to stick out of the wheel well further??
Its the opposite of what youre thinking.
