Back Spacing ?

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FASTBACK340

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I have an opportunityto buy a pair of 15" X 7" small bolt pattern rims with 4.5" back spacing. Will these work with un-relocated rear springs? I'd hate like Hell to buy them and find out I can't use them.... I really want to keep the steelies w/ dog dishes, but need more tire.

Help..... :read2:
 
Yes. I have 15X7s with a 4-1/4 backspace, and with a set of Cooper Cobra radials @ 245-60-15. I have 1/2 inch of space from the tire to the rear leafs..both sides.
So figure with 4-1/2 backspace you will have a 1/4 inch space between tire and springs.
Note:all cars are different and so are tire sizes.
 
I've got to agree with Soul on this one. I run the same rim dimensions as he does and the same size tire on a 71 dart. I thought you Barrcuda guys had a little more room to work with there. I'm SURE if I had another 1/4" BS I could run a 255. I'm close to the lip but have a lot more room on the leaf spring side to work with.
 
Here,s a pic..

trim 063.jpg
 
FASTBACK340 said:
I have an opportunityto buy a pair of 15" X 7" small bolt pattern rims with 4.5" back spacing. Will these work with un-relocated rear springs? I'd hate like Hell to buy them and find out I can't use them.... I really want to keep the steelies w/ dog dishes, but need more tire.

Help..... :read2:
Click to expand...

If you dont buy them can you pass on the in fo to me, thx
 
Thanks for posting the pictures Brock! Looks like you can go even larger out back there. If the seller agrees to the price I'm going to grab them. If not I'll pass on the sellers info.

I have 245-60-14 out back now..... I'd like to go 265-60-15. I'll have to go grab some junk tires and check clearances.
 
bvt69dart said:
John, Here are the pic's I promised. 15X7" 4.5" backspace 235/60R/15
Click to expand...

What brand rims are those? Are those stock Mopar 15x7? Are they large bolt pattern with aftermarket axles or redriled small bolt pattern axles.

The aftermarket large bolt pattern axles have thicker flanges that push the rims about about 1/4" per side.

Stock 15x7 rims are 4 1/4 backspacing. The reproduction Mopar Rallyes, Steel wheels and magnum 500's are 4 1/4 backspacing. If you get a 15x8 size in those model repro rims you get 4.5 backspacing.

I have 15x8 4 1/2 backspacing with 245/50/15 tires on my Barracuda. They are about 3/8 to 1/2" clearance. That car has redriled small bolt pattern axles. Also my tires are 50 series Z rated and have a straigher (less bulge) sidewall compared to a 245/60/15.

On my 68 Dart I have a small bolt pattern 15x7 rim with 4 1/4" backspacing with 245/60/15's It is close inside and out. So those will also have the thin flange. On really agressive cornering one side barely rubs the outside and the other side barely rubs the springs. Obviously the rear in is not dead nuts 100% centered on the body.
 
sorry, i've never tried that small of tires...a 255/60/15 will fit on a 4.25 backspace with leafs in stock location...i run 275/60 on the same rim but had to go with offset shackles...:)
 
Steve, I have the LBP 8 3/4 rear axles on my car. When I put them on, I measured the distance from hub flange to bearing mount. It was exactly the same as my original SBP axles.
 
doug 371 said:
sorry, i've never tried that small of tires...a 255/60/15 will fit on a 4.25 backspace with leafs in stock location...i run 275/60 on the same rim but had to go with offset shackles...:)
Click to expand...

What axles do you have? Original small bolt patter or aftermarket or shortened respined large bolt pattern axles? It makes a difference.
 
These are 15 x 8 w/4.5 bs and 275/60-15`s in the stock wheelwell. It should work and if it`s too close you can buy 1/8" spacers from Summit for about $25.00.

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I am running 15x8" rims with 4.5" of back spacing on the rear of my 68 Barracuda with 255/60 tires. There is about 1/2" of space to the spring and the widest part of the tire.

IMG_0810.jpg


If the rim had less back spacing a 275/60 would fit with no concerns.

John, FWIW, I have never heard of a 265/60 tire, I think you will need to work with 255/60, 275/60 or 295/60.
 
I had a 15X8.5", 4-7/8" back spacing with 255-60-15s on my 69. It was close but fit. You'll be fine. And I agree, Theres no 265-60 that I have seen. a 275-50 fits great back there but a 7" wide rim may be a bit narrow.
 
I just bought those 15" X 7" SBP rims for my car. Looks like I'm buying tires and painting rims. The person I bought the rims from has a second set he might want to sell. Anyone interested? I'll get price & contact info.


Dave: Are those BFGoodrich's on your car? That's the exact look I want.... EXACT look.... and I'm already running BFG's. Those are 255/60/15"?
 
Yes, they are Radial T/A's 215/60-15 on the front and 155/60-15 on the rear. I tried 225/60-15 on the front but when you turn the wheel the one turning in would touch the front edge of the wheel well. A narrower rim or one with more back spacing would have moved the tire in enough to clear. I also have the 73+ A-body disks on the front which widens the track and contributes to the tire touching the fender during turns.
 
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