Is a 10" wide rim too much for a Defender 90?

[RovinC]

I currently have 35 x 12.5 x 16 SSR's on GCR 16x 7" rims on my '97 D90 ST.

I love the looks of them, but since this is a 10ply tire, for the tread to run flat and not bulge in the center lugs, I need to keep them at 18-20 psi. Driving across country at that psi isn't acceptable of course, and airing them higher will wear out the center lugs.

So, I am going to get different wheels, but am not sure of what width to go for.
Interco says a minimum of an 8" wheel for these tire, but at what point will I have fenderwell clearance? I had to trim the flares already of course, and wont trim any metal.
I was thinking of a 9" or 10" wheel, but don't think I have ever seen anyone with any, so is there a reason why?

MY main goal is to get the tread to run flat and have at least 34 psi in the tires.

Anyone have any ideas?

Thanks

[HSV Rangie]

only real reason is that they are ilegal in most startes as you are only allowed 25mm wider than std and only increase the wheel track by 25mm Not 100% on w/track. may be 50mm.


but then most cars are ilegal any way so its up to you.

Run them.

Michael.

[ISUZUROVER]

only real reason is that they are ilegal in most startes as you are only allowed 25mm wider than std and only increase the wheel track by 25mm Not 100% on w/track. may be 50mm.


but then most cars are ilegal any way so its up to you.

Run them.

Michael.

I think he is in the US Michael - oh and on solid (F&R) axle 4x4's the rule is 50mm, 25mm for cars and all other 4x4 (IFS / IFS-IRS).

Personally I like to run the narrowest rim I can for a given tyre size, because it means that the rim will be less prone to damage and also that the tyre will stay on the rim better without beadlocks.

[Maxtd5def]

Ben,

where did you pick up that 50mm rule for solid axle 4WDs?

I thought it was 25mm too. Thats my recollection of the NSW guidelines anyway.

Regards
Max P

[ISUZUROVER]

Ben,

where did you pick up that 50mm rule for solid axle 4WDs?

I thought it was 25mm too. Thats my recollection of the NSW guidelines anyway.

Regards
Max P

It is in the QLD modifications guide. I have posted a link to the guide before - search under my username.

The guides usually follow the ADR's and I can't see that QLD would be stricter than NSW on tyres.

[Bush65]

According to document vsi09.pdf from RTA NSW (some time ago, so may not be current).

Wheels can be wider by 26mm than max from factory without informing RTA, but track must not increase more than 25mm.

Over 26mm wider rim needs engineering. Even then max width depends on weight and can be up to 51mm wider if over 1201kg tare, but not more than 204mm for 4wd vehicle. And track can't be increased by more than 25mm.

[ISUZUROVER]

The QLD regs are here...

http://www.transport.qld.gov.au/qt/driv ... ations.pdf


Page 19:

"Off-road passenger vehicles fitted with front and rear beam axles, may have an increase in track up to 50mm beyond the maximum specified by the manufacturer for the particular model of vehicle".

I can't believe there is one issue on which the NSW regs are stricter than the QLD regs.

[Gwagensteve]

In my experience with swampers, they tend to crown unless they have plenty of rim on them. I think they will still crown on 8's, and will need 10's to avoid crowning, however, 10's add a alot of leverage to bearings, tie rods etc. I think I would not be alone in not advising going past an 8 on a late model land rover.

If is was my car (I should be so lucky) I think I would run the stock 16X7's with Q78 16's - over 35" tall and about 11 wide. These are recommended on a 7" rim and will sit under your car very nicely. I think they are a massively underrated tyre, and cheap too.

34psi is a lot of air to run in a 10 ply swamper on a relatively light car. I ran 6ply Q78 15's on a 2500kg car (G wagen) for years and they have worn very flat across the tread and I never ever went over 30psi, ran 8-12psi offroad.

Ps I am running old worn 35 12.5 baja claws on my G atm and on beadlocked 15X7's (effectively 7.5) they are crowning terribly. They spent most of their life on 8's, and have about 8mm of tread at the centre and about 13-15mm at the TWI's, near the outside edge of the tread. really wish I was still running the q78's.