Results 1 to 9 of 9
Thread: offset question, need help..
-
02-13-2008 #1
Registered User
- Join Date
- Jan 2006
- Location
- Snohomish, Washington
- Posts
- 2,235
offset question, need help..
Hey guys, just bought a set of wheels from my friend who bought them for his bmw but never mounted them. I dont know the acutall backspace of the wheels. just the offset, the front is 40 mm and the wheel is 19x8.5, the rear is 19x9.5 45 mm, what is the best way to figure out the backspace for the wheels?? The wheels are ASA JH8 wheels.
Matt
-
02-13-2008 #2
Registered User
- Join Date
- Nov 2006
- Location
- Flo-rida
- Posts
- 1,204
Front 19x8.5, +40mm= 6.3"
Rear 19x9.5, +45mm= 7.0"
1993 Camaro Z28
2001 Camaro Z28
1969 Camaro
02-13-2008 #3
Registered User
- Join Date
- May 2002
- Location
- Northern California
- Posts
- 10,716
Easiest way is to drop it on its face and put a tape measure to it.
I always get dizzy trying to explain it. But the jist is. Fronts are 40mm from the center line of the rim. Rears are 45mm Positive and negative is in or out. Being BMW i'd be safe to assume they are positive, meaning they are a deep offset or in.
Fronts 8.5= 9.5 actual width center would be 4.75 so add 40mm to that is
Rears 9.5= 10.5 actual width center would be 5.25 so add 45mm to that is....crapp, you fast typers suck....well I did need 10 minutes to regain my land legs.
LOL yeah what he said!
MrQuick ΜΟΛ'ΩΝ ΛΑΒ'Ε
02-13-2008 #4
Registered User
- Join Date
- Jul 2006
- Location
- San Diego, CA
- Posts
- 599
The way to measure backspace if you have them in front of you is to lay them face down (preferably on a cloth so you don't scratch them). Put a straight edge across the back of the rim. Measure from the straight edge down to the flat part that goes against the rotor. That's your backspace.
You can also calculate backspace if you know the offset (assuming you know if it's positive or negative offset) You can see it on this site:
http://www.usacomp.com/terms.htm
Recall that 25.4mm = 1 inch
02-13-2008 #5
Registered User
- Join Date
- Nov 2006
- Location
- Flo-rida
- Posts
- 1,204
Vince you didnt have typing 101? haha
1993 Camaro Z28
2001 Camaro Z28
1969 Camaro
02-13-2008 #6
Registered User
- Join Date
- Jul 2006
- Location
- San Diego, CA
- Posts
- 599
...man, I guess I'm an even slower typer!
Last edited by Boesch; 02-13-2008 at 07:28 PM.
02-13-2008 #7
Registered User
- Join Date
- May 2002
- Location
- Northern California
- Posts
- 10,716
ROFL....wait...how do you spell? LOL
Originally Posted by Project69
MrQuick ΜΟΛ'ΩΝ ΛΑΒ'Ε
02-13-2008 #8
Registered User
- Join Date
- May 2002
- Location
- Northern California
- Posts
- 10,716
LOL...actually not, you beat me to my reply to your reply...wait...nevermind. Haaa haaaaa Originally Posted by Boesch
Did you get all that Muth??MrQuick ΜΟΛ'ΩΝ ΛΑΒ'Ε
02-13-2008 #9
Registered User
- Join Date
- Jan 2006
- Location
- Snohomish, Washington
- Posts
- 2,235
haha yes I did thanks, so assuming that the rear wheels have 7inches of backspace. and im going to need about 4.75 inchs of backspace for them to be center im going to have to run a space that is 2.25 inchs?? and same kind of thing for the front???
also vince maybe you can go look at my post in the disc brakes too
thanks alot guys for the help and the link.Matt
Reply With Quote
