C5 wheel offsets.
Thread Starter
Safety Car
Joined: Jul 2001
Posts: 3,524
Likes: 1
From: Pinellas Florida Misfit
Cruise-In III Veteran
C5 wheel offsets.
Does anyone know the wheel offsets for the various C5 wheels? Mainly looking for 97-98 style wheels and the Y2K style thin 5 spokes.
Thanks!
Jim
Thanks!
Jim
Le Mans Master
Joined: Apr 1999
Posts: 6,129
Likes: 14
From: Vette
Re: C5 wheel offsets. (Springer's 95)
Check out my spreadsheet for some info.
I believe 97-99 and Y2K had same offsets, but not 100% sure
Hope this helps…
I believe 97-99 and Y2K had same offsets, but not 100% sure
Hope this helps…
Thread Starter
Safety Car
Joined: Jul 2001
Posts: 3,524
Likes: 1
From: Pinellas Florida Misfit
Cruise-In III Veteran
Re: C5 wheel offsets. (wallstAL)
Thanks all.. looking to go with C5 rims on my C4... but I'm wondering if the 18 inch rears would fit all the way around.
Advanced
Joined: Jan 2001
Posts: 63
Likes: 0
From: Escondido 92025 Ca
Re: C5 wheel offsets. (EuG)
eug THANKS FOR THE SPREAD SHEET INFO ITS VERY HELPFUL. I am thinking about taking my 01 c5 y2k rears and moving them to the front and buying two more y2k style 18 s' with zo6 size & rear offset(i have bpp rear brake scoops and there is little to no clearance inside,apparently they use the z06 air duct) do you know if any forum member has tried this. also will the front caliper work as areplacment on the rear w/o prop valve or anti lock problems?
Le Mans Master
Joined: Apr 1999
Posts: 6,129
Likes: 14
From: Vette
Re: C5 wheel offsets. (Bob Caffey)
I am thinking about taking my 01 c5 y2k rears and moving them to the front and buying two more y2k style 18 s' with zo6 size & rear offset(i have bpp rear brake scoops and there is little to no clearance inside,apparently they use the z06 air duct) do you know if any forum member has tried this.
Yours truly! :D
I’ve got my stock Y2K rears on the front and 10.5x18” Y2K look alikes on the rear. No ducts though…not sure if it makes any difference. I’ve got a bunch of pics on my page if you wanna see. Just follow the link in the sig.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Melting Slicks
Joined: Aug 1999
Posts: 2,540
Likes: 2
From: Milwaukee WI
LS1Edit Guru
Cruise-In I Veteran
Cruise-In II Veteran
Cruise-In III Veteran
Re: C5 wheel offsets.
Isn't the backspacing the only dimension that really matters here?
Backspacing equals the distance from the surface that contacts the brake rotor to the innermost point on the rim. Mine were about 8.75" on my 18x9.5 factory rims...
What is offset? and wouldnt it figure into the backspacing anyway? It seems to me that the only thing that matters is how far "inside" the rim will go in order to prevent the tire from hitting the inside of the fender liner. Perhaps I'm missing something here..
Backspacing equals the distance from the surface that contacts the brake rotor to the innermost point on the rim. Mine were about 8.75" on my 18x9.5 factory rims...
What is offset? and wouldnt it figure into the backspacing anyway? It seems to me that the only thing that matters is how far "inside" the rim will go in order to prevent the tire from hitting the inside of the fender liner. Perhaps I'm missing something here..
Advanced
Joined: Jan 2001
Posts: 63
Likes: 0
From: Escondido 92025 Ca
Re: C5 wheel offsets. (nevrenuf)
Yes, you are right, whether you call it backspace or the distance the wheel center is OFFSET from the wheel centerline makes little difference. My question which may have been poorly stated is "are the z06 rear wheels different in any dimension from c5 rear other than the width. thank you for your input. bob
[Modified by Bob Caffey, 4:34 PM 12/8/2001]
[Modified by Bob Caffey, 4:34 PM 12/8/2001]
Le Mans Master
Joined: Apr 2000
Posts: 7,248
Likes: 0
Re: C5 wheel offsets. (nevrenuf)
I see a lot of backspacing calcs that look wrong to me.
From the Tire Rack tech section on wheels, Offset is defined as the distance between the edge where the wheel mounts & the CENTERLINE of the wheel. So, a 9.5" rim would have a 4.75" centerline. A 60mm offset is arount 2.5" from centerline. So the backspacing should be 4.75" + 2.5" = 7.25" although the common word on stock Y2K 9.5" backspacing is 7.5", so I don't see where the math is working, or not working for that matter.
What am I or others missing here?
I don't believe you subtract the offset from the wheel width to determine backspacing. Offset is not defined from the outside edge of the wheel, but as the distance to centerline of the wheel where the weight should be most evenly distributed.
From the Tire Rack tech section on wheels, Offset is defined as the distance between the edge where the wheel mounts & the CENTERLINE of the wheel. So, a 9.5" rim would have a 4.75" centerline. A 60mm offset is arount 2.5" from centerline. So the backspacing should be 4.75" + 2.5" = 7.25" although the common word on stock Y2K 9.5" backspacing is 7.5", so I don't see where the math is working, or not working for that matter.
What am I or others missing here?
I don't believe you subtract the offset from the wheel width to determine backspacing. Offset is not defined from the outside edge of the wheel, but as the distance to centerline of the wheel where the weight should be most evenly distributed.
Le Mans Master
Joined: Apr 1999
Posts: 6,129
Likes: 14
From: Vette
Re: C5 wheel offsets. (MelloYellow)
Bob,
They’re exact Z06 rear wheel dimensions. Width, offset, everthing….
Mello
You pretty much got everything right, but you left out the lip width which should be added to determine the backspacing (~0.5”)
[Modified by EuG, 7:52 PM 12/8/2001]
do your rear 18's (given they are wider) have the c5 or z06 offset?
Mello
I don't see where the math is working, or not working for that matter.
[Modified by EuG, 7:52 PM 12/8/2001]
Le Mans Master
Joined: Apr 2000
Posts: 7,248
Likes: 0
Re: C5 wheel offsets. (EuG)
Hmm. Makes sense, thx!
But I don't get why John/CCW says stock backspacing is 7.5" ? Everyone seems to have a diff number. Bottom line, I think I'm going to have to just pull the damn wheels and measure the backspacing on each before I start cutting my wheels up.
What would centerline be then for a 9.5" ?
[Modified by MelloYellow, 8:06 PM 12/8/2001]
But I don't get why John/CCW says stock backspacing is 7.5" ? Everyone seems to have a diff number. Bottom line, I think I'm going to have to just pull the damn wheels and measure the backspacing on each before I start cutting my wheels up.
What would centerline be then for a 9.5" ?
[Modified by MelloYellow, 8:06 PM 12/8/2001]
Melting Slicks
Joined: Oct 2001
Posts: 2,643
Likes: 32
From: SoCal
Re: C5 wheel offsets. (EuG)
EuG's spreadsheet is absolutely corrent.
Here is Fikse info... matches EuG exactly: http://www.fikse.com/offsets.html
Here is Fikse info... matches EuG exactly: http://www.fikse.com/offsets.html
