How are people not getting rub on 20x10 rims

[Sean880]

1. A 10 inch wheel in 48 offset with a 285 tyre will definitely rub the rear guards and you will have to roll the rear guard lips for clearance.

2. To clear the rear guards as they are now you were correct the first time with 54 offset. Actually anything from 53p to 57p offset will be fine with the 285 tyre for decent clearance on each side of the tyre and no guard rolling. If you were not lowering the car you could get away with 50p and no guard rolling with the 285 tyre but I would definitely go for a little higher offset if you intend lowering the suspension.

3. Once the car is lowered, if you get any rubbing with that 285 tyre and high wheel offset, it will be from contact with the bumper bracket that sits just inside the rear guard. If a tyre touches the bracket with enough suspension movement once the new package is fitted and the suspension is lowered you will have to modify the bracket or grind it down so it clears the tyre.

4. I would go for a higher offset wheel as you propose so the 285 tyres clear the rear guards as they are now and you avoid guard rolling.

So..........
- 285 rear tyre
- no guard rolling
- 10 inch rear wheel, offset 53 - 57p
- lowered suspension
- check for contact with rear bumper bracket when fitted.

 

[JoeVF2]

ive noticed lately as im looking to buy rims at the moment, the 35 profile tyres on the expensive brand tyres are actually alot thicker these days, they look like 40 profile, which is why i was recommended 30 profile for the rear of mine as it basically is the size of the old 35 profile, for some reason theres been a change from what i can see, especially the michellin pilot sports, i was tripping, 35 profile is bloody thick as! i look at the 35's i have on my Au falcon daily and there way thinner?? its very odd.

 

[Sean880]

No mate nothing odd. Tyre profile is expressed as a % of the tread width and always has been and still is.

So take 4 different 35 profile tyres and they all have different side wall heights because the the tread widths are different.

235 35 20,, 245 35 20,, 255 35 20,, 275 35 20,, 285 35 20

All these are 35 profile tyres but the sidewall height differs in every one of them with the 285/35/20 having the highest side wall because it has the widest tread size. The sidewall height difference will be relatively small from one size 35 profile tyre to the next size up in 35 profile but it won't be exactly the same.

If you are looking to fit a 20 inch set of staggered wheels on your VF with a 9.5 or 10 inch REAR wheel, you will need a 30 profile tyre in the REAR if you are going to fit a 245/35/20 tyre up front. This is because you need to match the front and rear tyre diameters as close as possible.

So if you run 245 35 20 on the front you will need a 275 30 20 or a 285 30 20 REAR tyre for a close match in tyre diameter. A 275/35/20 or 285/35/20 are both significantly bigger in diameter than your 245 35 20 tyre because the sidewall is higher in each case.

Here are the diameters:

245 35 20 680 mm
275 30 20 674 mm
285 30 20 680 mm

275 35 20 700 mm
285 35 20 708 mm

Yes in this example you would be advised to put a 30 profile tyre in the rear because the seller was matching the tyre diameters front and rear as close as possible and knew what he was doing.

 

[Mattricho]

1. A 10 inch wheel in 48 offset with a 285 tyre will definitely rub the rear guards and you will have to roll the rear guard lips for clearance.

2. To clear the rear guards as they are now you were correct the first time with 54 offset. Actually anything from 53p to 57p offset will be fine with the 285 tyre for decent clearance on each side of the tyre and no guard rolling. If you were not lowering the car you could get away with 50p and no guard rolling with the 285 tyre but I would definitely go for a little higher offset if you intend lowering the suspension.

3. Once the car is lowered, if you get any rubbing with that 285 tyre and high wheel offset, it will be from contact with the bumper bracket that sits just inside the rear guard. If a tyre touches the bracket with enough suspension movement once the new package is fitted and the suspension is lowered you will have to modify the bracket or grind it down so it clears the tyre.

4. I would go for a higher offset wheel as you propose so the 285 tyres clear the rear guards as they are now and you avoid guard rolling.

So..........
- 285 rear tyre
- no guard rolling
- 10 inch rear wheel, offset 53 - 57p
- lowered suspension
- check for contact with rear bumper bracket when fitted.

Awesome Sean880 thank you for the info.
I’ll be going with a +54 offset..

merry Christmas everyone

 

[panhead]

1. A 10 inch wheel in 48 offset with a 285 tyre will definitely rub the rear guards and you will have to roll the rear guard lips for clearance.

2. To clear the rear guards as they are now you were correct the first time with 54 offset. Actually anything from 53p to 57p offset will be fine with the 285 tyre for decent clearance on each side of the tyre and no guard rolling. If you were not lowering the car you could get away with 50p and no guard rolling with the 285 tyre but I would definitely go for a little higher offset if you intend lowering the suspension.

3. Once the car is lowered, if you get any rubbing with that 285 tyre and high wheel offset, it will be from contact with the bumper bracket that sits just inside the rear guard. If a tyre touches the bracket with enough suspension movement once the new package is fitted and the suspension is lowered you will have to modify the bracket or grind it down so it clears the tyre.

4. I would go for a higher offset wheel as you propose so the 285 tyres clear the rear guards as they are now and you avoid guard rolling.

So..........
- 285 rear tyre
- no guard rolling
- 10 inch rear wheel, offset 53 - 57p
- lowered suspension
- check for contact with rear bumper bracket when fitted.

I've posted these photos many times to show a good offset for a 20x10 rim on the rear of a VE/VF.

There isn't any fouling of the guards for either combo even with the rear tray weighted down with a load.


20x10 +50 offset
285/30R20
Lowered with King SSL
No guard rolling

20x10 +50 offset
295/30R20
Lowered with King SSSL HD
Guards are rolled

For reference the front rim is 20x8.5 +45 offset with the tyre in the first photo being a 245/35R20 and the tyre in the second photo being a 255/35R20.

In my opinion the offset for the front rim is too conservative or better still a 20x9 inch rim would be better with say a +40 offset .




.

 

[dimetime]

if you have a safe offset (45p to 57p) tyre size shouldnt be a problem most 30/275 or even 30/285.
the further you push the offset (due to either brake clearence or "stance") the skinnier the tyre you have to use.
most people are looking to have a good mix of filling out the guards, having the clearence and not having to stretch there tyres to the point of a rough ride.
id personally suggest 40p offset with 30/275 and a guard roll.
most scrubbing that people get is having the wrong tyre size due to their offset, having the ride to low with an aggressive offset and having to much bounce in the spring.
easist solution would be get coilovers and have a firm ride but no chance of scrubbing

 

[JoeVF2]

No mate nothing odd. Tyre profile is expressed as a % of the tread width and always has been and still is.

So take 4 different 35 profile tyres and they all have different side wall heights because the the tread widths are different.

235 35 20,, 245 35 20,, 255 35 20,, 275 35 20,, 285 35 20

All these are 35 profile tyres but the sidewall height differs in every one of them with the 285/35/20 having the highest side wall because it has the widest tread size. The sidewall height difference will be relatively small from one size 35 profile tyre to the next size up in 35 profile but it won't be exactly the same.

If you are looking to fit a 20 inch set of staggered wheels on your VF with a 9.5 or 10 inch REAR wheel, you will need a 30 profile tyre in the REAR if you are going to fit a 245/35/20 tyre up front. This is because you need to match the front and rear tyre diameters as close as possible.

So if you run 245 35 20 on the front you will need a 275 30 20 or a 285 30 20 REAR tyre for a close match in tyre diameter. A 275/35/20 or 285/35/20 are both significantly bigger in diameter than your 245 35 20 tyre because the sidewall is higher in each case.

Here are the diameters:

245 35 20 680 mm
275 30 20 674 mm
285 30 20 680 mm

275 35 20 700 mm
285 35 20 708 mm

Yes in this example you would be advised to put a 30 profile tyre in the rear because the seller was matching the tyre diameters front and rear as close as possible and knew what he was doing.

thanks for the info mate, i was at the tyre place on saturday and we tried fitting vertini RF 1.1'S, the front was 255/35 fitted perfectly. the rear was 275/35 and when we dropped the car off the hoist and the tyres were sitting on the guards, they were nitto NT05 very tall tyre, swapping to a 30 profile
this wednesday for a more streetable tyre in the INVO'S. We are hoping to get away without minimal modifications to the rear guards, a nib here n there im happy with but definately not risking the guards being rolled and damaged.

 

[JoeVF2]

hey guys, can anyone tell me if im going to have any problems running the following,
front 255x35 (overall diameter 692mm)
rear 275x30 (overall diameter 673mm)

 

[dimetime]

hey guys, can anyone tell me if im going to have any problems running the following,
front 255x35 (overall diameter 692mm)
rear 275x30 (overall diameter 673mm)

on stock gm wheels or aftermarket? if aftermarket what offset

 

[JoeVF2]

on stock gm wheels or aftermarket? if aftermarket what offset

vertini rf 1.1's, his saying the offset is 15+, so basically the other day we tried a 275/35/20 and the tyre was scraping on the guard and nearly pulled it down soon as i rolled off the hoist. going for the staggered look but if i cant make it work il put the money towards a cam and tune.