offset??
Thread Starter
Instructor
Joined: Aug 2001
Posts: 201
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From: San Mateo CA
offset??
I may be buying a set of wheels but dunno anything about offset. The available wheels are listed before with backspacing. Can someone tell me if it will fit my Z06 corvette? Will performance be changed if i go with these wheels? What is the normal offset for a 2002 Z06 corvette?
19x9.5's have 7 inches of backspacing
20x10's have 7 3/8 of backspacing
Really appreciate it if someone can help me with this cause i dont want to throw thousands of dollars into a set of rims i cant use.
Thanks!
19x9.5's have 7 inches of backspacing
20x10's have 7 3/8 of backspacing
Really appreciate it if someone can help me with this cause i dont want to throw thousands of dollars into a set of rims i cant use.
Thanks!
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
For those sizes, you ideally would want a 54mm offset in the front, and 52mm offset in the rear. These would place the wheel perfectly flush with the fenderline, or the same as a stock Z06 wheel does, and not stick out at all.
I know this because those are the offsets of my 19x9.5 and 20x10's.
My calculations from those backspace dimensions is that these wheels are 45mm offset front, and 48mm offset rear. (backspace dimension is from the mounting hub surface to the back lip of the wheel...offset is the distance from the mounting hub to the true center of the wheel. Also, a wheel's stated width is measured from the inside of the lips, where the tire bead sits, but the backspace dimension is to the outer edge of the lip....so to properly calculate this, you need to add (typically) 1/2" lip thickness both inside and out, making the overall outside edge dimension of the wheel 1" wider.
For example, on the 20x10... if you measure the overall width of the wheel, it should measure 11". Divide that by 2 (5.5") and there's your centerline of the wheel. The backspace dimension was stated to be 7 3/8"..so subtract 5.5" (half the overall width of the wheel) from that and you get 1 7/8". This is the offset dimension, the distance from the hub to the center of the wheel. To convert to mm, multiply by 25.4, and that equals 47.6mm.
Bottom line is they would fit, but the front wheels may stick out slightly, maybe 3/8"...the rears would be better, only about 1/8" more than ideal. The ideal backspace dimensions for those width wheels.would be 7 3/8" front, and 7.5" rear
Hopefully someone can double-check my math before you make your final decision.
I know this because those are the offsets of my 19x9.5 and 20x10's.
My calculations from those backspace dimensions is that these wheels are 45mm offset front, and 48mm offset rear. (backspace dimension is from the mounting hub surface to the back lip of the wheel...offset is the distance from the mounting hub to the true center of the wheel. Also, a wheel's stated width is measured from the inside of the lips, where the tire bead sits, but the backspace dimension is to the outer edge of the lip....so to properly calculate this, you need to add (typically) 1/2" lip thickness both inside and out, making the overall outside edge dimension of the wheel 1" wider.
For example, on the 20x10... if you measure the overall width of the wheel, it should measure 11". Divide that by 2 (5.5") and there's your centerline of the wheel. The backspace dimension was stated to be 7 3/8"..so subtract 5.5" (half the overall width of the wheel) from that and you get 1 7/8". This is the offset dimension, the distance from the hub to the center of the wheel. To convert to mm, multiply by 25.4, and that equals 47.6mm.
Bottom line is they would fit, but the front wheels may stick out slightly, maybe 3/8"...the rears would be better, only about 1/8" more than ideal. The ideal backspace dimensions for those width wheels.would be 7 3/8" front, and 7.5" rear
Hopefully someone can double-check my math before you make your final decision.
Last edited by Y2Kvert4me; Aug 2, 2004 at 06:07 PM.
