Wheel Backspacing and Offset Question

[stingray427]

Quick question, will a 15" x 10" rim with a 3.650 backspace and a -47.00mm offset fit on a 77' with four wheel disc brakes?

Thanks.

 

[stingray427]

Anyone...?

 

[Labbster]

It should. I have a 76 with rims with 4 inch backspacing. I had to put 1/4 spacers from BCbroncos on and they barely fit. So, if all else is equal, they should fit.

 

[stingray427]

It should. I have a 76 with rims with 4 inch backspacing. I had to put 1/4 spacers from BCbroncos on and they barely fit. So, if all else is equal, they should fit.

Thanks for the reply, but I am a bit confused. You say a 4" backspace plus spacers barely fit, but these rims I am referring to have only a 3.65 inch backspace. Why will they fit or are you saying that I will need a spacer also?

 

[Naildriver111]

I am running 16 x 8 with 4 1/4" backspacing and no spacers, the larger diameter helps clear the steering knuckles, but if you run fat tires they would rub the radius arms.

 

[Labbster]

my wheels have 4 inches so with the spacer it, in reality makes it just like a rim with 3.75 inch back spacing. Therefore, your setup would fit even better! Go for it.

 

[Quick & Dirty]

Thanks for the reply, but I am a bit confused. You say a 4" backspace plus spacers barely fit, but these rims I am referring to have only a 3.65 inch backspace. Why will they fit or are you saying that I will need a spacer also?

Backspace is the distance from wheel mounting surface to the inside of the rim. 4" plus 1/4" spacer is 3.75" backspace. You should have .1" more clearance for the steering arm, caliper and radius arm. If you are worried about fender clearance it's a different ball game.

 

[stingray427]

Thanks for all of the informative replies.

 

[msweb]

Backspace is the distance from wheel mounting surface to the inside of the rim.

I just found this thread while looking for some help with the terminology, namely backspacing.

The distance would be measured from the inside of the wheel mounting surface to the inside of the rim, right?


****Edit - If that's right, what's offset?

Thanks, and please go easy on me for stupid questions ?:?

 

[SaddleUp]

I just found this thread while looking for some help with the terminology, namely backspacing.

The distance would be measured from the inside of the wheel mounting surface to the inside of the rim, right?


****Edit - If that's right, what's offset?

Thanks, and please go easy on me for stupid questions ?:?

Yes, that is correct on backspacing. Offset I think is the distanc the mounting surface is from the center of the wheel. I.E. I think an 8" rim with 3 1/2" of backsapcing would have 1/2" of offset. Check one of the big wheel sites to verify on that one.

 

[tabascom16]

They should just fit. I have 3 5/8" backspaced 15" rims and the wheel weights are around 1/8th to 1/16th of an inch away from the steering knuckles on my 76. I have never had any problems.

 

[saxman]

Has anyone had any problems using the 1/4" spacers like this?

 

[rcmbronc]

I have a 76 with 15x8 wheels with 3.75" backspacing. They worked great with no interference. I went tie-rod over with stonecrusher and added those 1/4" spacers from BC (the ones Saxman has shown) and it clears fine.

 

[saxman]

I have a 76 with 15x8 wheels with 3.75" backspacing. They worked great with no interference. I went tie-rod over with stonecrusher and added those 1/4" spacers from BC (the ones Saxman has shown) and it clears fine.

Ok, that helps me a lot rcmbronc! How much rub on the radius arms are you getting with your tires?

 

[rcmbronc]

I get a little bit at full turn. I was thinking about adding 1.25" spacers but it really is not real bad.

 

[saxman]

I found a steel rim that is 15x8 w/ 3.25" of backspace. Do you guys think that should be ok on a '77 with disc brakes. I am going to run 33x12.50's. I know astark is running that setup on his '76 chasis and it looks good IMO.

 

[saxman]

bump....anyone?

 

[rcmbronc]

That should work fine