Is there any legal way to run big tyres 35+

[chrismav]

i've read all i can on this topic and it seems like there's no winning. There's a catch 22 between ADR rules for needing a run 8.5inch or wider from these tyres (whatever the manufacturer says) and then wider rims being illegal from an increased track width point of view. It also seems that even if an engineer will approve it, when insurance issues get going the engineer's cert won't hold any authority. I just don't want to sink all my money into a big lift and have to run ridiculously small tyres on road. (GQ)


questions:
Is there any way to win?

What about axle swaps for large axles (Dana, Rockwell or even unimog) - seems like all the money to lock, change gearing and to still be illegal might work out the same to axle swap. How much does this cost? Can it be legalised.

What about really skinny 35s on 7-8" rims like swamper radials ssr 35x10.50R15LT

Thanks for any input

[Wooders]

Firstly forget using Swamper and road legal in the same sentence
Second - before embarking on the mod - discuss it with the enigineer. You'll need to demonstrate that you've factored in the gearing for correct speddo etc, Then you'll need to convice the engineer that the braes are upto spec etc.

Best thing is to talk to the engineer before starting.
I;m surre that it's physically possible. but you'll need to do some research and you'll need to carefully consider the effect on things like wheel bearings.

[SAWZALL]

From what I've found out an engineer won't even consider it unless the axles are fully floating. Then he may sign off on 37's.....MAY!!!

[Jmcdonald]

There are other things that no one has mentioned that an engineer "at least in Vic" will want to know as well. Brakes must be rated to stop your 4b with the size tyres you choose! There is little chance getting bigger than 35" due to change in center of gravity and increased side wall flex, you need to use a 16" with 35's and if you a super assy 17" with say 40" MTRs but your center of gravity will be and issue also in Vic you are only allowed a small amount of tyre size increase by Vic Roads! Dose any one know what the go is, dose an engineer have the right to let you use lager wheels over what Vic Roads says?

Here is a thourght make a once off register vehicle ie not made by a manifactor so there for you are not limited by factory rules. This means if you ran say uni mog diffs I think they are rated up 60" ballon tyres and you could make the thing road worth and get a engineer to sing off on it you would be laughing:>

[CRUSHU]

well, in NSW, it should be relativley easy, but I think you will need a floater axle in the rear.
Goliath (from the last Tuff Truck) was engineered with 38" tyres in NSW.
www.procomp.com.au suggest using 35" tyres on 8" rims, dunno about the U.S. site.



Forget Rockwells, I seriously looked at them for my F150, but you need about 12" - 15" of lift, to run them. Because they weigh so much, you need all new suspension, and steering, to make them legal. Basicly, cut off anything that hangs off the chassis, and start again.

[slosh]

Assuming you have GQ Patrol? You'd have to talk to engineer about diff swap but I do know that 315/75 x 16 tyres (eg MTR's) are manufactured to fit onto 16 x 8 rims. These are 35 inch tall and I specifically bought this size with engineering in mind.

Most people say why bother with 16 inch rims, all the tyres and rims are EXXY, but I reckon it's worth it if you get the tyres engineered.

Josh.