Thread: Wheel backspace question

Tweet

I'm going to be installing American Racing Salt Flat Specials on my 3W, and I have to let them know what backspace I want. I've got Ford backing plates with Buick finned drums on the front, and a Ford 8" rear end with stock Ford drums on the back. What backspace should I order?
Thanks,
Randy

This is similar to asking "what woman would I get along with?"

Think about it. The clearance between the tire and your body is determined by (1) axle width, (2) tire size and profile, (3) wheel width, and (4) wheel backspacing. Also, the location of the body components (and frame rails) relative to the wheel flange affect your clearance. For most cars, the axle mounting method affects the side to side movement of the system. I know of famous cars that allowed the car to hit the body when the car accelerated.

The backspacing determines how close the tire sidewall comes to the rear inner fender (or body), etc. Each setup is different.....
you must measure your car. If you have front fenders, the same applies to the fronts. Open front wheels are a little more forgiving but still need consdieration to look correct. One of the best ways is to mount your exact tires on a wheel (that is the width you are going to use) and install it. Then, you can measure how far in or out you need to move the backspacing to achieve the correct clearance.

There is a nifty gauge to measure this but it costs something like $350. http://autowaretech.com/mountmate/pricing.html

Dont use measurements from someone else's car....you might have a set of new wheels that wont fit!!!!

If your buying the wheels from a local dealer he should be able to measure for you. Its not complicated but it has to be right.

I applied all my degrees to the best of my ability and ordered a non-standard back space. Granted I have a relatively unusual set-up. Then when I got the wheels I wished I had increased the backspace a half to 3/4 inch. It's only money

IMO if possible get a wheel/tire to try out before you buy ............

Kitz

This is similar to asking "what woman would I get along with?"


A nymphomaniac with a lot of money ???




Don

Sounds like this is going to be more complicated than my truck...then I just went to the tire store and told them Torque Thrust II's, 16x8...
Anyway, part of my question was related to how much of the finned Buick drum do I want to have exposed, because the backspace will have an effect on that, but now I also see that if the back space is too little, then when the wheels are turned, the tire will hit the frame, and my problem is as I said, the Salt Flat Specials are all custom built, so in order to get one to try, you have to pay for it...hmmmmm...
Oh by the way, it's a 3W Coupe, highboy, so no fenders

resin, Put a tire on it, any tire. Then measure how much room you have from the edge of that tire. Add that to the backspace of the rim you put on, Then subtract what space you want between the frame and the rim. Remeber the tire may stick out over the rim alittle. this would give you a reasonable backspace, This should work for you, I did it when I rebuilt my camaro and I got the rims to be the right size I wanted.

On the front, the inside tire will not hit the frame...it will rub the 4-bars or hairpins first. This is unavoidable with these cars, hence the use of steering stops. Deuce Factory has nice stainless king pin locks that double as steering stops.

On the rear, you want at least 1" space from the tire's "bulge" to the body - at the top of the suspension travel. The easiest way to measure is to get the tires without rims and mock them up. Measure from your wheel mounting surface, back to the inside bead. That is your back space.

The company you are ordering these from shoud be able to supply you with a measurment sheet so you can get the correct offsets, I have been looking at buying wire wheels and Dayton faxed me a sheet so I could measure my ride. The correct sizes can make or brake a car / truck

See if this will help

Don't know but heres another shot I use these sheets for setting up narrowed rears. it may help.