going from 7" to 8" wide rims....what does this change?

[AussieAnth]

In terms of airing down a set of 265/70/16's , are you better off on an 8" wheel? Any difference in contact patch should be negligible.

My thinking is, with a 7" wheel, there will be more rubber spread outside of the lip as they bag out, thus increasing the chance of a pinch flat, and possibly more chance of burping air & popping the tyre off.

Is that sound reasoning? Any other factors to consider?

[biggibbo]

I actually found the opposite when I had 8" steelies, which I have now swapped for 7" Alloys.

Due to greater width, the tyres tended to pop off the bead more easily - haven't popped one since I swapped over.

[ag9111]

When you air down a tyre the width only changes marginally. Its the length of the contact patch that grows significantly.
Think a tank track

[Cage]

OK, I've read six squillion threads, re-read this one several times and I think I've got this right.

I'm currently running the factory 16x7 alloy rims with +38 offset, and 265/75's Maxxis.

I have about 12mm clearance from the flares to the widest part of the tyres.

Now if I go to an 8" rim I'm going to be right on the clearance limit with the same offset rim.

The rims I'm looking at are +30 offset so if I'm figuring this correctly I'll be 8mm over the allowed clearance.
However I'm hoping that the wider rim will take a bit of the bag out of the tyre and I'll only be a smidgen over. The edges of the rim and the tread are well within the flares.

Does this sound right? Hell, it seemed to take me yonks to get my head around the way a rim moves in and out with changes to offset.

[paddstar69]

Sounds right, not too sure how much bag will be taken out, if anything i think it will allow the side wall to bag out a touch. If the side wall stays the same with the wider rim and fitting up the new rims with a +30, i dont think 8mm will cause any issues, like you said the tread and rim are inside the guard.
Thinking it will probably look good considering you would have moved the outer edge of the rim 20mm outward compared to the original rim.

[4wd26]

Are you planning to run the same 265 wide tyre?
If you are then the only change is the offset or 8mm

You still have 10mm to the flare.

[Cage]

Are you planning to run the same 265 wide tyre?
If you are then the only change is the offset or 8mm

You still have 10mm to the flare.

Cheers.

Yes I'm keeping the 265/75tyres. I realise that the width at the tread will stay the same but I thought the wider rim may pull the sidewall out a bit.

One other thing I'm wondering about is that the 8" rim will decrease inner clearance by 12.5mm but the +30 offset will pull that back to about 4mm. Should that cause any clearance problems.

[Cage]

Had my Maxxis AT-980 265/75's fitted to some 16 x 8" 25P Speedy Yukons yesterday.

The combination of the reduced offset and the wider rim now has about 10mm of tyre visible outside the flares.

I'm currently trying 34psi front and 32psi rear and so far it feels pretty good with none of the tyre wall flexing I could feel on the 7" rims.

Hope it doesn't attract Plod's attention, or throw too much crap along the sides.

[srb]

Can you guys double check if i'm correct on this?

I was thinking of going a 16x8 +15 rim but know this will be over the 50mm NSW legal track limit by 21mm from a standard 16x7'' rim or... 8.5mm from the standard 17x7.5'' rim.

If I go a +20 offset in an 8'' rim I'll be 1.5mm inside the legal limit if by going from the widest standard 17'' Triton rim of 7.5'' Does this sound right?

I know this will make my 265 tyres stick past the flares but... I've got brush bars at the front and have an alloy tray with guards wider than the standard factory flares, so does anyone know if this makes it legal seeing the tyres wont be protruding past any of the attached body work? If this is the case Im tempted to go with the +15 offset if it doesn't look too out there.

[ag9111]

16x8, +15 is what I run.
Stop being a skirt and just do it, It looks good. Ditch those pussy hummer rims

[srb]

16x8, +15 is what I run.
Stop being a skirt and just do it, It looks good. Ditch those pussy hummer rims

The Hummer rims are better than standard and have proven to be a cheap reliable option. But yeah I would like to go the +15's as I need more stability off road to keep the wife from climbing out the window all the time.

Have you got a good photo of how far the wheels stick out?

[ag9111]

No up the side shots that I can remember Steve.
It is really close, only 5 or so mm in it. You get a little bit more mud up the side but not excessive.
The wider stance makes the ute look lower as well.

As I said, man up

[Cage]

I was thinking of going a 16x8 +15 rim but know this will be over the 50mm NSW legal track limit by 21mm from a standard 16x7'' rim or... 8.5mm from the standard 17x7.5'' rim.

If I go a +20 offset in an 8'' rim I'll be 1.5mm inside the legal limit if by going from the widest standard 17'' Triton rim of 7.5'' Does this sound right?

Interesting bringing the 7.5" GLX-R rims into the equation. I had the same thoughts and wondered if I needed to could I argue that the vehicles are identical underneath, so to speak, the difference between them being some drive train goodies, the rims, different side steps, sports bars and some niceties in the cabin. Oh and a different tyre placard.

With my set-up, see above, I'm only 1mm over the allowable track increase but we all know how pedantic the insurance and transport folk can be.

Be interesting to see what others think.