Original Wheel Size?
Drifting
Joined: Mar 2001
Posts: 1,411
Likes: 2
From: St. Louis, Missouri
Re: Original Wheel Size? (VettePower)
I believe the earlier rally wheels were 6" and later ones were 7". N90 alloys are 8", I believe. Usually, backspacing on OEM wheels is 1/2 the width.
Anyone, feel free to keep me honest here.
Anyone, feel free to keep me honest here.
Race Director
Joined: Apr 1999
Posts: 15,145
Likes: 477
From: NM
Re: Original Wheel Size? (Black68Vette)
15x8, 4.5 inch backspacing I believe... 15x7 was one year only, 68, everything after was the 15x8, before that was 15x6
What is this .5 offset that people are talking about :confused:
tom...
Pro
Joined: Aug 2000
Posts: 713
Likes: 1
From: plymouth mass
Re: Original Wheel Size? (VettePower)
Tom73
I made a slight mistake yesterday. The 15X8 ralley wheels have .50 of offset and the back spacing is 3.80. I saw these numbers a few months back on the NCRS Borad.
I made a slight mistake yesterday. The 15X8 ralley wheels have .50 of offset and the back spacing is 3.80. I saw these numbers a few months back on the NCRS Borad.
Pro
Joined: Feb 2002
Posts: 536
Likes: 0
From: Lutz FL
Re: Original Wheel Size? (Tom73)
What is this .5 offset that people are talking about :confused:
tom...
tom...
Race Director
Joined: Apr 1999
Posts: 15,145
Likes: 477
From: NM
Re: Original Wheel Size? (charles dion)
Tom73
I made a slight mistake yesterday. The 15X8 ralley wheels have .50 of offset and the back spacing is 3.80. I saw these numbers a few months back on the NCRS Borad.
I made a slight mistake yesterday. The 15X8 ralley wheels have .50 of offset and the back spacing is 3.80. I saw these numbers a few months back on the NCRS Borad.
I found that reference in the NCRS archive. In fact I have the -.50 offset listed in the tech area of my web page, but I have no idea of what it is refering to. I understand the backspacing but do not know what offset is. By the way that back spacing of 3.80 was refering to the 68 15X7" wheel, not the 8" wheel.
Who can explain the -.50 offset?
tom...
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Pro
Joined: Aug 2000
Posts: 713
Likes: 1
From: plymouth mass
Re: Original Wheel Size? (Tom73)
Tom73:
The offset is the distance the mounting surface is from the center of the wheel. If the hub is mounted more to the rear it is minus and if it's mounted more to the front of the wheel it's plus back spacing. I don't understand why a 15x8 ralley doen't have a 3.50 backspacing. If you measure the backspacing it is about 3.875.
The offset is the distance the mounting surface is from the center of the wheel. If the hub is mounted more to the rear it is minus and if it's mounted more to the front of the wheel it's plus back spacing. I don't understand why a 15x8 ralley doen't have a 3.50 backspacing. If you measure the backspacing it is about 3.875.
Race Director
Joined: Apr 1999
Posts: 15,145
Likes: 477
From: NM
Re: Original Wheel Size? (charles dion)
Wow,
I just went out and measured one of the Ralley Wheels off of my '73. Back spacing is about 3 7/8". But front spacing is about 4 1/2". This is measuring from the inside of the wheel lip to the bolt hole.
tom...
I just went out and measured one of the Ralley Wheels off of my '73. Back spacing is about 3 7/8". But front spacing is about 4 1/2". This is measuring from the inside of the wheel lip to the bolt hole.
tom...