Tire Fitment Question

[split1atom]

Hey everyone. I want to shoehorn a set of tires in the back of my 89 town. I was looking at new rims when I ran across some custom 9" cruiser rims. They have 275 60 15s on them. The backspace is 4". Can I get them on. Rolling the fender is no problem! Thanks in advance. Bob

[sly]

you may need a 0.25 inch spacer...


Check the FAQ out. http://www.grandmarq.net/vb/showthre...ase-Read-First!

[zoomie]

should be just fine, although not just a lip roll , but i think a stiffer set of springs should be in order, the stockers even with police shocks will rub iff you have a bunch wieght in the back say a bunch of campign stuff ,and engine parts like heads intake and whatnot

[split1atom]

I just got a set of PI rear springs from Mcninetyone. I want the fender as full as possible, but not if the car has to be jacked up above it. I like the car to just sit down over the rears. Now if you cant get your finger between the tire and fender, Im good with that! Still think it will work?

[sly]

9 inch tires... yes... but spacing must be correct. Without spacers you may not even need to roll the lip any. With spacers it would just center the tire better on the axles. Even 10 inch wide tires, when centered perfectly, should clear a rolled lip and the control arms by just enough. you should have a good half on each side with 9s.

[split1atom]

Slymer, thanks for the additional info. I did just want to point out that they are 9" rims, but isnt a 275 tire nearly 11" at its widest. Just wanted to make sure I was clear on the details. They guy is a big car guy and going through a lot to ensure they fit for me. He stated a few minutes ago that they were actually more of a 4.25" backspacing which is good for me. He is taking lots of pics of the different measurements and sending so I can verify myself. I will most likely throw them on here so I can get more eyes on it. By the way, love the window sticker.

[johnunit]

Just something to consider: An old panther's rear end has a LOT of side to side slop. Probably pushing an inch of side to side movement in extreme situations, especially if you haven't replaced your control arm bushings. That means so close you can't stick a finger between the tire and fender has a very high likelyhood of rubbing in hard cornering. You definitely couldn't get away with the clearances you seen on "stanced" sport compact cars and the like, no matter the springs. there's just too much slop in the system. Push the car side to side as hard as you can at the rear bumper then watch the rear wheels, you'll see what mean.

[split1atom]

John, good point! I am getting the sway bar and lower arms with new bushings to go with the PI springs, but still very valid. I just got actual measurements from the guy. I'll post them below and see what you guys think. May just be pushing it too much.

[split1atom]

1, backspacing is technically defined as "measurement from centerline of a wheel". it depends on wheel design (how fat the lip is, whether there is a lip at all, and of course how WIDE the wheel is to begin with etc). posistive offsets tend to be associated with newer cars/front wheel drive cars (deep dish in back), and negative offsets tend to be associated with older cars (deep dish in front).

i think in OLD car terms, and other oldtimers like me tend to view the OEM setting as ZERO offset...or around four inches...when trying to decide what kind of custom wheel will work on our old cars. high POSTIVE offsets definitily do NOT work on old RWD cars as we talked.

1. the actual backspacing on my wheels IS 4.25 inches...this helps your cause and i have changed the auction accordingly.

using the definition above, the centerline of my wheels is five inches as the wheel is ten inches wide LIP TO LIP and nine inches wide BEAD TO BEAD. so using the convention above they have an NEGATIVE offset about 0.5 inches...meaning they have bias toward the OUTSIDE of the car BEFORE a tire is mounted.

2. i have included four pictures. (a) wheel/tire combo at WIDEST POINT is 11.5 inches. (b) wheel/tire diameter is about 28 inches with my particular tire....this should NOT be a problem at ALL for you. (c) measured from the CENTER OF THE HUB to the WIDEST point on the BACK of tire is about 5 inches. (d) measured from the CENTER OF THE HUB to the WIDEST POINT on the FRONT of tire is about 6.5 inches

3. these measurements are NOT scientific regarding the backspacing, and the tire gets a little FATTER under a vehicle load. and all 275/60 tires are NOT exactly the same dimensions, body flex under acceleration is possible, etc. so i only add those as possible variations that i am unable to quantify for you with high precision.

my judgement remains as we talked, but i am a little more confidient that you can PROBABLY make this work as you want. the bias in this setup would be a NEGATIVE offset, and your looking at TWO inches of bias toward the OUTSIDE and one inch toward the INSIDE versus the stock OEM tire.wheel combo.

i believe you should have that two inch clearance from the HUB to the INSIDE of the rear WHEEL well lip...but i urge you to measure that as best you can to confirm ..eyeballing the OEM tire mounted to car and using the data i gave you above.

on the back side, unless something is REALLY close like a suspension part or a brake line or tailpipe or something, to the BACK of the OEM tire now, you probably have the inch you need

[zoomie]

i had us wheel 5x8 in rims on my old car, nto sure of offset as they came off a mark vii, but i stuck 275/60/15s on there with no issues especially after i put the limo springs on. apparently my bushings were spot on becuse they were w pita to move, that rear stayed planted no matter what i did, unless i was goosing it in the snow and even then it was snow drift time hehe.

[sly]

yes... 10 inch rims with appropriate tires (about) is what one person is running on here, but they have rather stout rear suspension with poly bushings all around to remove most of the slop.

[split1atom]

Well, after getting his 6.5" from mounting face to widest part of the front sidewall email, I ordered the wheels. From mounting face to rolled fender I have about 6.75". Being that the tires are 60's, the tread isn't but maybe 10". That gives me a decent amount of clearance and keeps the tire completely inside the fender......I hope. I'll have pics as soon as I can get them mounted. Thanks for all the help.

[sly]

I thought there was a good foot of space in there... sure enough. We're here to help.

[split1atom]

The 275/60/15's are in and on! I had to cut the fender lip to the quick, but they made it. The rims had a 1/2" offset. Shame they werent 0". I would have liked them in just a 1/4" but look good anyways. Waiting on the matching front rims now.