15x8s rubbing when I turn?

[rikubot]

Hi guys, I got a set of magnum 500s recently and lately I've noticed they've been rubbing when I make even slight turns into parking lots and such. Even at slow speeds. Anyway, from what I've read, this combo isn't supposed to rub. The tires are 275/60s. Any knowledge is appreciated!

[BLK 68 R/T]

 Backs or front rubbing when you turn? Wheel backspace? 275/60 is a little big for the front IMO.

[c00nhunterjoe]

I had 275/60's on the front of mine just to see how they would fit. They would catch the front lower lip of the fender, cleared everything else lock to lock on my car, but mine sits higher in the front then most guys seem to like. A 275/50 would have cleared my car without issue in the front.
    If his are rubbing in the rear, then we need to know if it is inboard on the spring, or outboard on the 1/4. If the backspacing is right, there should be no problem. 295s will clear with room to spare.

[rikubot]

Sorry guys I should have been more informative. It's inboard on the back wheels, 4.5 inch back spacing I believe. I have read that 295s would clear too so that's why I'm so confused. It appears to be rubbing on the leaf spring, but there's about an inch and a half clearance. The wear on the car isn't very obvious wherever it's happening

[BLK 68 R/T]

Is your car lowered? with a 4.5 in backspace you should have lots of room. weak or sagging springs could possibly cause enough body roll to cause the tire to rub inside the wheel well.

[rikubot]

It's not lowered, and the leaf springs don't seem to sag, but the bracket clamp things that hold them together are loose ish?

[tan top]

   seems odd , with a 4 & a half inch back space ..... have you double checked the back space your self ?  ... there should be lots of room ? , first thing that popped into my head is silly I know  , maybe ...     buckled wheel , bent  axle shaft  , massive bulge in tire wall  , silly I know ,  as you would know all about / feel these while driving  ...  because seems odd rubbing with that back space & tire set up

have you got a picture of the under side ,  gap between springs & wheel/ tire now .   are they stock oem type springs & spring clamps ? ....

[b5blue]

Nothing should be loose at all? (Anyplace.) I want to run 15x8 all around so I'm interested in what's going on. I'd rub chalk on the tire areas suspect and drive the car to make it rub so you can look for witness marks or transfer of the chalk?  Got any pics of where this could be going on?

[rikubot]

I'll get you guys a picture when I get off work. Definitely going to have to stop and get some chalk too.

[rikubot]

I have not checked the backspace myself, but that's a great idea. I'll have to do that asap.

[HPP]

Yes, typically that combo fits without issue, however, there are any number of variables that can impact that. Factory assembly tolerances, aftermarket assembly tolerances, quarter panel replacement,offset housings, wheel back space, spring location, worn bushings...

I can't see where 1.5" of clearance would rub, but if your bushings are allowing excessive movement, your backspace isn't really 4.5" or something flat out was assembled incorrectly, this combo should work.

Typically 15x8 Magnums have 4.25 backspace, so they shouldn't rub, but I'd verify it. Does it rub both sides or just one side? Is it on the spring or on the wheel housing? You need to remove the tire and look for the rub marks.  

[Mike DC]

  
You guys are talking about a 10" wide tread on an 8" wide rim.  That's way too far of a mismatch.  It allows the tread too much side-to-side movement in relation to the wheel rim.   

[RallyeMike]

Incorrect. An 8 inch rim for a 275/60/15 is in the middle of acceptable rim width for a BFG tire. No problem there.

My guess is that if you have 1.5" clearance from tire bulge to spring, the backspacing probably is not 4.5. You are likely rubbing on the outside fenderwell. It certainly isnt the springs rubbing with that much clearance unless you forgot to tighten your lug nuts!

Maybe you dont have a stock width axle in your car since the 15x8 roadwheels all seem to have about 4.5 backspace?  

[Mike DC]

                   

Incorrect. An 8 inch rim for a 275/60/15 is in the middle of acceptable rim width for a BFG tire. No problem there.

275?  Looking on a ruler, that figure is really almost 11 inches.  The OEM's don't do combos like that.  The tire will mount up and drive but I don't think it's a good pairing.  

[funknut]

                   

Incorrect. An 8 inch rim for a 275/60/15 is in the middle of acceptable rim width for a BFG tire. No problem there.

275?  Looking on a ruler, that figure is really almost 11 inches.  The OEM's don't do combos like that.  The tire will mount up and drive but I don't think it's a good pairing.  

I run the same tire on the Wheel Vintiques Mag 500 rim (15x8 w/ 4.5" BS) in the rear with no issues.  Stock rear suspension with the exception of Caltracs. 

An 11" tire on an 8" wheel sounded a bit extreme to me too, but I checked the BFG site and sure enough they recommend 7.5" - 9.5" rims for 275/60R15:

http://www.bfgoodrichtires.com/tire-selector/category/hot-rod-tires/radial-t-a/tire-details

[c00nhunterjoe]

275/60 on an 8.5

[RallyeMike]

Quote from: Mike DC (formerly miked) on Yesterday at 09:40:41 PM

                 

Quote

Incorrect. An 8 inch rim for a 275/60/15 is in the middle of acceptable rim width for a BFG tire. No problem there.



275?  Looking on a ruler, that figure is really almost 11 inches.  The OEM's don't do combos like that.  The tire will mount up and drive but I don't think it's a good pairing.  

I run the same tire on the Wheel Vintiques Mag 500 rim (15x8 w/ 4.5" BS) in the rear with no issues.  Stock rear suspension with the exception of Caltracs.  

An 11" tire on an 8" wheel sounded a bit extreme to me too, but I checked the BFG site and sure enough they recommend 7.5" - 9.5" rims for 275/60R15:

http://www.bfgoodrichtires.com/tire-selector/category/hot-rod-tires/radial-t-a/tire-details

Yes, that was based on what I knew the manf recommends. A radial street tire in this size is made to have sidewall bulge wider than the tread and the bead seat. There also is not 100% consistency between what one manf calls a "275" tire and another does, so using a ruler to call it 11 inches is only an approximation. Remember that an 8-inch rim is actually about 9 inches outside to outside. The 8 inch measurement is the width at the bead. In this case, an 11 inch wide tire at the bulge is only 1 inch wider per side than the wheel. This is just as intentionally designed.


Back on track... I'd like to hear what the OP finally discovered is the issue?

[rikubot]

Still no resolution on the issue . I haven't been able to do much looking into it because work, but if it helps at all I am running cooper Cobras.

[c00nhunterjoe]

Copper cobras are a great street tire. Very soft compound,

[cdr]

I am running 325 50 15 on a 15x10, 5in bs & have plenty of room on the inside.

[HPP]

Until rikubot gets out there and checks, we're all just throwing darts at the wall.

Also, make sure you check and measure both sides.While these cars seem symmetrical, they very often are not.

[rikubot]

Here's a couple pics of the clearance:

[rikubot]

pic

[cdr]

pic

you need to pull the wheel & measure the back space.

[rikubot]

I was finally able to measure my back spacing today. It's 4.5in from where the wheel sits against the drum to the wheel lip, and a little over 5.5in from the center to the end of the tire bulge.

[cdr]

you need to measure the rear end drum face to drum face. 

[c00nhunterjoe]

Have you visually seen where it is rubbing?

[rikubot]

I'll see if I can get that measurement tomorrow.

Nah, it's not rubbing hard enough to leave a trace. I'm about 80% sure it's leaf spring, but that's a solid 1.5 in away from the tire...

[cdr]

I'll see if I can get that measurement tomorrow.

Nah, it's not rubbing hard enough to leave a trace. I'm about 80% sure it's leaf spring, but that's a solid 1.5 in away from the tire...

it is probably rubbing on the inner wheel well . if i get my car in a bind pulling in my drive way it just touches the inner well .

[cdr]

from what I can find 60 1/8 drum to drum 1968 - 1970 b body

[rikubot]

Thanks for the info, cdr. I'll try to get those numbers before the weather gets bad. I wouldn't be surprised if that's what's happening 

[HPP]

I'll see if I can get that measurement tomorrow.

Nah, it's not rubbing hard enough to leave a trace. I'm about 80% sure it's leaf spring, but that's a solid 1.5 in away from the tire...

it is probably rubbing on the inner wheel well . if i get my car in a bind pulling in my drive way it just touches the inner well .

Based on the pictures you've provided, I tend to agree with that its the inner well. Thinking of the way the rear end pivots, it will angle the tires into the inner wheel housing. The whole axle rises and falls at angles to the wells when the body rolls. The leaf springs tend to either rub all the time, or not at all. The sidewall of the tire half way up the diamter of the tire where it crosses the leaf spring very rarely deflects at all much less an inch and a half.

[RallyeMike]

I'm about 80% sure it's leaf spring, but that's a solid 1.5 in away from the tire...

I agree with HPP. Looking at your photos you can write off the leaf springs as the source.

If you determine that the inner well is the contact point, your choices to eliminate the rubbing are new wheels, wider axle, or wheel spacers. I'm personally not thrilled with wheel spacers, but they are available from lots of sources.

[rikubot]

That makes a lot of sense. Huge bummer, but that's gotta be it. I'll smear some chalk on it and go around the block just to make sure. Two questions: how difficult/expensive is an axle swap? And how come you are not a fan of wheel spacers? To be honest, im not either, especially if it means I have to pull the axle anyway and change out my wheel studs.

[rikubot]

Or should I just run it? Lol

[cdr]

look at the other side & see if it is the same distance .

[rikubot]

It looks just about the same.

[cdr]

It looks just about the same.

like I said measure drum to drum, 65-67 rear end is a little narrower. & will bolt in.

[RallyeMike]

An axle swap is not very difficult, but it depends on how easy it is to find one and what condition its in. Physically replacing one with another is quite simple other than it's heavy.

I'm not a fan of wheel spacers because you lose the hub centric fit of your wheel to the axle. Of course lots of mag wheels create this condition. Not a disaster... just not as good as running without them. They are an inexpensive alternative to solving tire clearance problems. 

[rikubot]

Please excuse me if this question is too stupid, but what the the "hub centric fit?" Haha

[HPP]

like I said measure drum to drum, 65-67 rear end is a little narrower. & will bolt in.

If his rubbing is on the inner fender well, a narrower rear would be a bad idea. If its rubbing on the outer lip, then it would be the best solution. we need rikubot to confirm where the rubbing occurs.

Another alternative is a wheel with less negative offset. This would pull the wheel/tire away from the inner fender. Or more positive offset, to pull it away from the opening lip.

hub-centric means the hub opening in the wheel rests on the hub lip on the axle. This puts the location and support for the wheel directly on the axle with the wheel stud providign clamping force and shear resistance. Without being hub centric, this loading is put on the  wheel studs instead of the hub. 

We really need you to confirm the contact point.

Whether or not you should do something about depends on where it is, how hard it is, and how often it is contacting. Also whether or not it is occurring on  both sides or only one is a factor as well as they may drive different corrections. Like I said previously, it is odd that a 275 on an 8" rim would rub in the rear, so something in your vehicle is different than a number of other cars.

[cdr]

like I said measure drum to drum, 65-67 rear end is a little narrower. & will bolt in.

If his rubbing is on the inner fender well, a narrower rear would be a bad idea. If its rubbing on the outer lip, then it would be the best solution. we need rikubot to confirm where the rubbing occurs.

Another alternative is a wheel with less negative offset. This would pull the wheel/tire away from the inner fender. Or more positive offset, to pull it away from the opening lip.

hub-centric means the hub opening in the wheel rests on the hub lip on the axle. This puts the location and support for the wheel directly on the axle with the wheel stud providign clamping force and shear resistance. Without being hub centric, this loading is put on the  wheel studs instead of the hub.  

We really need you to confirm the contact point.

Whether or not you should do something about depends on where it is, how hard it is, and how often it is contacting. Also whether or not it is occurring on  both sides or only one is a factor as well as they may drive different corrections. Like I said previously, it is odd that a 275 on an 8" rim would rub in the rear, so something in your vehicle is different than a number of other cars.

I did not say to put a narrower rear end in the car .  my point was that someone MAY have put a 65-67 housing in this car.

[rikubot]

It would not surprise me one bit if my rear axles were swapped at one point. My poor baby has been tinkered with in pretty much every way possible. One reason I went with the 15x8 magnums was because everyone said there was plenty of room with NO rubbing issues. It's raining out now otherwise I'd get that drum to drum measurement for you guys. Thanks for all the interest and help so far

[c00nhunterjoe]

Based on the pictures posted, it should clear. If its rubbing, it should be barely. Nothing a ball peen hammer in the proper location cant fix and be undetectable. Chalk-testdrive- report back 1st.