NEED SOME EXPLANATION ON WHEEL OFFSET AND BACKSPACING

ARPM

Member

Jul 8, 2004

116

0

16

PUERTO RICO

Jul 20, 2008

#1

• Jul 20, 2008

• #1

I was browsing some wheels today at *bay and checked a few bullit style wheels for the classics with the following specs, 17"x8", 0 offset,4.50 bs. As far a i can remember the formula for calculating offset is, offset=W- bs/2. So if the width is 8" and the backspacing is 4.50" the offset is positive "1.625. Am i wrong?

 

R

ron67fb

Founding Member

Aug 3, 2001

1,117

0

36

SF Bay area, CA

Jul 20, 2008

#2

• Jul 20, 2008

• #2

https://www.rsracing.com/tech-wheel.html

 

DK832

New Member

Apr 11, 2006

291

0

0

Copenhagen, DK

Jul 21, 2008

#3

• Jul 21, 2008

• #3

Vintage Wheel Works

 

9

96 DOHC Cobra

Founding Member

Oct 14, 2001

542

0

16

Cerritos, CA

Jul 21, 2008

#4

• Jul 21, 2008

• #4

DK832 said:

Vintage Wheel Works

Click to expand...

So, a 17 X 8 wheel is actually 9 inches wide.

 

I

INDSKYS

New Member

May 24, 2003

245

0

0

CALIFORNIA

Jul 23, 2008

#5

• Jul 23, 2008

• #5

I THINK I RAN A 4.5 REAR BS AND A 3.5 FRONT BS TO GET 16X8 WHELS AND TA KDWS TO FIT WITH NO FENDER ROLLING AND NO TIRE RUB IN REAR EVEN WITH PASSENGERS IN BACK . SHREDDING TIRES --SUX LOL 245-50 REARS 225-50 FRONT

 

ARPM

Member

Jul 8, 2004

116

0

16

PUERTO RICO

Jul 23, 2008

#6

• Jul 23, 2008

• #6

96 DOHC Cobra said:

So, a 17 X 8 wheel is actually 9 inches wide.

Click to expand...

that's exactly what i was talking about!

 

S

stang66convt

New Member

Apr 13, 2006

29

0

0

Jul 25, 2008

#7

• Jul 25, 2008

• #7

backspacing

i have 17x8 with 225/45/17 om a 66 mustang..offset-0
4.50 backspacing...have no problems

 

1

1985GT50

New Member

Jun 29, 2009

14

0

0

the epicenter

Jun 29, 2009

#8

• Jun 29, 2009

• #8

i always thought offset was wheel width minus backspace subtracted from width/2.... so (8/2) - (8-4.5) would be negative .5 inches or -12.7mm offset. what am i missing?

 

5

5280/4

New Member

May 21, 2009

201

0

0

Jun 30, 2009

#9

• Jun 30, 2009

• #9

1985GT50 said:

i always thought offset was wheel width minus backspace subtracted from width/2.... so (8/2) - (8-4.5) would be negative .5 inches or -12.7mm offset. what am i missing?

Click to expand...

you are right

maybe its a typo? but i also recall from somewhere with offset you measure the outside of the wheel for total width. not the inside bead like normal wheel measurements?

 

Capt Dan

New Member

Mar 31, 2005

237

0

0

College Station, Texas

Jun 30, 2009

#10

• Jun 30, 2009

• #10

The measurements are taken in different places. Assume a 1/2 inch lip on each side makes a rim that takes an 8" wide tire (measured from the inside face), 9"wide (measured from the outside face).