back spacing

[gary b]

wheelzman or somebody is there a rule of thumb on how to figure how much back spacing. from the end of the axel to the closest thing on the rear of the car is 6 in { four link bars} thanks gary b

[greenracing]

A lot depends on the width of the wheel and the tire. If you're running the "recommended wheel" for your tire, the tire specs usually tell you the section width, then you can roughly figure how far the tire is going to hang over the wheel.

I'm just mentioning this 'cause I spent a lot of time calculating and recalculating to get 12" tires to fit between my fenders and tubs....

[Billy Mac]

one thing I found a long time ago......place the tire you want to run under the car (without a wheel in it).....in the position you want it to ride.....then....measure from the inner bead to the mounting point of the rear end........this will get you in the ballpark of how much back-spacing you need........(placing a piece of 2x4 in between the beads, so that the beads are as far apart as your desired wheel width helps in this endeavor also....)
Good Luck

[wheelzman]

I always recommended that you buy the rims and tires then cut the rear end to fit but what Perry said, check the specs on your tire. The tread width is just that, then the section width is the overall width or the part of the tire that bulges out past the rim. The clearance problem is usually the radius of the inner fender well on the body. Many rims do not come in special offsets so unless you are running the normal drag rims that come in different offsets you better check that for clearance too. We, as drag racers, always seem to have the problem of stuffing something way to big in a place that was never intended for such. Also, is the tire going to grow at speed?? You must take all of these factors into consideration.

Sorry there is no such thing as an easy fix here. Good luck.

[pro70z28]

Wheelz' you need to invent an "easy button" for drag racers.
I'd take 1.....

[Bob Kraemer]

Wheelz' you need to invent an "easy button" for drag racers.
I'd take 1.....

Me 2

[wheelzman]

Wheelz' you need to invent an "easy button" for drag racers.
I'd take 1.....

I wish! Now I would be one rich son gun, wouldn't I? If I had one my 55 Chebbie would be rollin' now and I would be on my way to the DLN's.

[gary b]

guess i'll do some measuring. with this dragster fender well clearance is not a problem. but i want one [easy button] gary b

[wheelzman]

Here is the procedure for measuring.

A. Take a straight edge and place on the flange of the axle.
B. Measure to the nearest location on the body while rotating the axle.
C. Subtract the rim width from the sectional width.
D. Divide this by two to determine the sectional width that will protrude past the rim edge.
E. Add 1" for clearance between the body and tire.
F. Add D and E.
G. Subtract this amount from B and that should give you the backspacing for your application.

Now remember that the backspacing on a wheel is measured from where the wheel sits against the axle to the inner most edge of the rim.
Measuring the street side of the wheel and subtracting is not an option, it is incorrect.
I have included a few websites below to help you understand the above. If you have any questions please ask and I will try to help.

http://www.newstalgiawheel.com/wheelmeasurment.asp

http://chevyhiperformance.com/techarticles/92318/

[Doug]

HUH!!??

OK.. So, if a train leaves NY heading West at 73 MPH and a trail leaves CA heading east 68 MPH at the same time, How much does a philly chees steak, fries and a coke cost?

Seriously, that is the procedure that I used on my car. i found it on the summit site under tech.
15x8 with a 5" backspace. I thought it sounded strange but sure enough, it worked with a 275-60-25 M/T drag radial.

Then some drty, rotten, theiving, no good, sob stole them out of my garage!!!

But, i'm not bitter.