wheels differences: design, width...backspace, offset..
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
wheels differences: design, width...backspace, offset..
I have a 1990 convertible with stock wheels. Rims are all 17” x 9.5”with 275/40/zr17.
Question 1 : All 4 wheels are the same regarding backspacing and offset?? Any difference from front to rear?
Question 2 :’90 ZR1 (with 11” rear) have the same “directional” design as my ‘regular 90 vette? (see my signature for reference )
Question 1 : All 4 wheels are the same regarding backspacing and offset?? Any difference from front to rear?
Question 2 :’90 ZR1 (with 11” rear) have the same “directional” design as my ‘regular 90 vette? (see my signature for reference )
Drifting
Joined: Jul 2002
Posts: 1,705
Likes: 5
From: OKC Oklahoma
Re: wheels differences: design, width...backspace, offset.. (conv90)
I have a 1990 convertible with stock wheels. Rims are all 17” x 9.5”with 275/40/zr17.
Question 1 : All 4 wheels are the same regarding backspacing and offset?? Any difference from front to rear?
Question 1 : All 4 wheels are the same regarding backspacing and offset?? Any difference from front to rear?
Question 2 :’90 ZR1 (with 11” rear) have the same “directional” design as my ‘regular 90 vette? (see my signature for reference )
Team Owner
Joined: Sep 2001
Posts: 62,127
Likes: 1,727
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: wheels differences: design, width...backspace, offset.. (conv90)
your wheels are 17x9.5x56mm
ZR1 wheels are 17x11x50mm to fit under the bigger bumper.
ZR1 wheels are 17x11x50mm to fit under the bigger bumper.
Team Owner
Joined: Sep 2001
Posts: 62,127
Likes: 1,727
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: wheels differences: design, width...backspace, offset.. (JasonL)
oops, the Zr1 are 36mm for 17x11 and the Grand Sport was 50mm for the 17x11.
2nd Gear
Joined: Nov 2002
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Likes: 0
Re: wheels differences: design, width...backspace, offset.. (JasonL)
How exactly do you measure the offset? I have a 1995 Coupe (non-ZR1) with A-Mold ZR1 5 spoke silver painted wheels. The fronts are 9.5" and the rears are 11". If I can find a pair just like the front, will they fit on the rear with no problem?
kevino1@prodigy.net
kevino1@prodigy.net
Safety Car
Joined: Feb 2002
Posts: 4,212
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From: Sun City West Az
Re: wheels differences: design, width...backspace, offset.. (ussopportune)
your fronts should be a 56mm offset and they will fit on the back with the same off set as long as they are 9.5 x 17. Off set is measured from the wheel center line to the backside of the mounting surface (where the wheel mounts on to the studs.)
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
Re: wheels differences: design, width...backspace, offset.. (conv90)
Ok, let me know if I understand….
All 4 wheels on my 90 are the same, same offset, same backspace and same width (…Yes I have 2 left an 2 right due to the symmetrical ‘rotational’ design).
11” rear wheels from a 90 ZR1 have the same design as my car.
……..So if I can buy a REAR set of a 90 ZR1 I can install 315 rear tires?
Then…
GS rear 11 rims comes with 50mm or 56 mm offset (don’t remember if it’s 50 or 56…) and ZR1 comes with 36mm offset.
From this I can deduce that ZR1 tires will ‘stick out’ from rear fenders more than a GS set and
a ZR1 set will be less prone to rub (from inner side..).
I’m right???
A GS fender extension will be sufficient to cover the tire?
Anybody with a rear set of a 90 ZR1 wheels on sitting down…..?
All 4 wheels on my 90 are the same, same offset, same backspace and same width (…Yes I have 2 left an 2 right due to the symmetrical ‘rotational’ design).
11” rear wheels from a 90 ZR1 have the same design as my car.
……..So if I can buy a REAR set of a 90 ZR1 I can install 315 rear tires?
Then…
GS rear 11 rims comes with 50mm or 56 mm offset (don’t remember if it’s 50 or 56…) and ZR1 comes with 36mm offset.
From this I can deduce that ZR1 tires will ‘stick out’ from rear fenders more than a GS set and
a ZR1 set will be less prone to rub (from inner side..).
I’m right???
A GS fender extension will be sufficient to cover the tire?
Anybody with a rear set of a 90 ZR1 wheels on sitting down…..?
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Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
Re: wheels differences: design, width...backspace, offset.. (conv90)
From this I can deduce that ZR1 tires will ‘stick out’ from rear fenders more than a GS set and
a ZR1 set will be less prone to rub (from inner side..).
I’m right???
A GS fender extension will be sufficient to cover the tire?
Anybody with a rear set of a 90 ZR1 wheels on sitting down…..?
a ZR1 set will be less prone to rub (from inner side..).
I’m right???
A GS fender extension will be sufficient to cover the tire?
Anybody with a rear set of a 90 ZR1 wheels on sitting down…..?
Drifting
Joined: Jul 2002
Posts: 1,705
Likes: 5
From: OKC Oklahoma
Re: wheels differences: design, width...backspace, offset.. (vader86)
oops, the Zr1 are 36mm for 17x11 and the Grand Sport was 50mm for the 17x11.
I believe it's the other way around, the GS wheels will stick out further than the ZR1 wheels. That's why the GS has fender flares, to cover that part that sticks out. The smaller offset pulls the wider rim inside the wheel well more.
[Modified by _freakmonkeydogboy_, 10:04 AM 2/21/2003]
Instructor
Joined: Mar 2001
Posts: 230
Likes: 1
From: Phila. Pa.
Re: wheels differences: design, width...backspace, offset.. (Raistlin)
I've got an 86. Is there an 11 inch w/315 tire combo made that won't stick out a little with out a GS flare? If so, which one? Otherwise I'll stick with 17x9.5 wheel.
Drifting
Joined: Jul 2002
Posts: 1,705
Likes: 5
From: OKC Oklahoma
Re: wheels differences: design, width...backspace, offset.. (Cruz 86)
you can get spacers and run the GS offset wheels and they will maybe stick out neglegebly...maybe 1/4", hwever you could try it without the spacers and they would sit in even more, but i don't know if that would rub anything inside or not... :D
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: wheels differences: design, width...backspace, offset.. (Cruz 86)
I've got an 86. Is there an 11 inch w/315 tire combo made that won't stick out a little with out a GS flare? If so, which one? Otherwise I'll stick with 17x9.5 wheel.
Race Director
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From: Central TX
C5 of Year Finalist (appearance mods) 2019
Re: wheels differences: design, width...backspace, offset.. (conv90)
Anybody with a rear set of a 90 ZR1 wheels to sell…..? :rolleyes:
