what tires on 15x9 rear rims

[mickeypowa]

Hi guys !!
I need to change my rear tires which are almost dead !
For the moment I have 26 10.00 r15 mickey thompson sportsman tires, and there is only 0.5 inch left from the inside of the tire to the fram.
My rims are 15x9
What size should I take with the standard numbers ?
I was think of putting 295 50 r15 to have a good look, but its wider !! So maybe I should put some spacers ?
What kind of spacers I need ? hubcentric ? 70.3 or 70.5 ? 5x114.3 ? My car is a standard 1980 cutlass supreme ?

Thanks

 

[Texas82GP]

Do you know what the backspacing of your wheels is?

 

[mickeypowa]

Do you know what the backspacing of your wheels is?

No I don't know, I have to measure the distance between the back of the rim and the center surface, haven't I ?

 

[Texas82GP]

Backspacing is the measurement from the wheel mounting surface to the inside edge of the wheel....

 

[Texas82GP]

A 26"x10" tire translates to a 255/55/15 but that is an oddball size. A 255/50/15 is a 25"x10" tire, again, an oddball size. A 255/60/15 is a 27"×10" tire and is a popular size (tires are available in this size).

A 295 likely won't fit your car (too wide) without modifications (roll wheel lip, frame notch). Let us know what your backspacing is and hopefully one of the tire fitment gurus will chime in on what will fit.

Some guys run 275/60/15's on the back (28"x10.8"), which is a popular (tires are available) tire size but that is a lot of tire to stuff under one of these cars. They may not fit without modification. Some drag radials are available in 275/50/15 (25.8"×10.8") but again, that's a very wide tire for these cars.

 

[UNGN]

.5" to the frame should be fine if the control arm bushings are good and it's .5" on both sides.

255/60 is your best bet for tire. Wider than this and you'll likely get rubbing.

 

[motorheadmike]

275/60/15s will work fine and look bad *ss.

Why are people so afraid of big(ger) tires on these cars?

 

[UNGN]

275/60/15s will work fine and look bad *ss.

Why are people so afraid of big(ger) tires on these cars?

Because Tahiti is a long way to send tires that rub back from.

I would go 275/60 on my car, but I know they will work with my wheels. On 15X9's with unknown backspacing, on the beach in Tahiti, I don't know if I would risk it.

 

[mickeypowa]

Hi guys !
At first thank you all for your help.
I have some news : I withdrew the rear wheels to have the informations you need :

The backspace of my rims is : 4.55 inches as you can see en the photo :


It is written 15x8J in my rims : what does it mean ? because I think they are 9 inches wide, not 8... ?

but my backspace is 4.5 inch. and the ET0 mean the surface is in the center of the rim so 4.5*2=9 inch wide rim ?


My tires are really bad at some spots, I guess my problem that the rear of the car which is swinging comes from the rear tires


The hub of the rear left wheel is 70.5mm wide, so it seems to be the rusty original one. When I try to move the bolts, there is a little play in it, is it normal ???


The hub of the rear right wheel is 69.6mm wide, so it has been replaced. There is absolutely no play in the bolds on the contrary of the left wheel.


here is a video of the play of the left wheel :

and a video of the hub turning in drive mode :

my questions :

Should I replace the left hub by a 69.6mm that doesn't move ? in order to have the same size on each side ! is it difficult to change ?
My rims are not hub centric mounted for the moment, I would like to do it : so I would need hub centric spacers of 69.7mm. Because I would like to put 275 60 tires with 1 inch spacers, what do you think about it ?

The inside diameter of the rims is 82.5mm, so I need hubcentric rings that goes from 69.6 mm inside and 82.5mm outside ? where can I find such rings ??


Thanks for your help guys !

mickeypowa

 

[UNGN]

15X8J, unless they have been widened, is 8" wheels.

The overall width of the wheel is about 9", but wheel width is measured inside, where the tire bead sets. Zero offset wheels have 9-16mm more backspacing due to the wheel rim width (different construction wheels have different rim thicknesses). The ideal ET for the back of a G-body is about -10mm.

The rear end doesn't have "hubs", it has axles that are held in place with C clips at the differential. Remove these C clips and the axles pull right out. The Right axle looks different. like it was bent or broke in the past, and has been replaced with aftermarket. The play looks like it is in the drums. swap the drums side to side and see if the play follows the drum. Drums are relatively cheap and you may need a new one. Don't worry about circumferential (rotational) play. When the wheel is bolted tight, this goes away.

1" spaces are probably too much unless the back of the car is jacked up way in the air. It probably only needs 3/8"... which puts it in the longer stud/shim spacer range vs. the bolt on "wheel adapter" range.