Tyre Size - new NCOP

[gu4800]

I was having a squiz at the new NCOP (National Code of Practice) for light vehicles and came across this.

Don't know if this has been covered here before, but does anybody having anything else constructive on this?

(Says 4wd's can go 50mm bigger than standard in tyres - at least that's how I interperet it). The "Bulletin" is dated 1 Feb 2006.

It also says something about it being used in conjunction with the relevant jursidiction, etc, etc.

Comments welcome. Anyone have experience with the new "code" - is this now a national overriding code? If not, why have it if the states then have different rules.

Thanks, and keep it constructive.

[Beastmavster]

Getting answers on this new code of practice is hard and I havent got down there to get answers face to face. You'll have to go to QLD transport in Spring Hill.. preferably take another vehicle so you cant get inspected on the spot.


If you're able to get interpretation on exactly what is meant by standard size, what that means down to the mm, and how it is meant to be presented I would love a copy - post it up here.

As we all know tyre sizes with the same markings can be very different and this is part of the controversy.



Likewise I'd like to know how exactly we determine exactly what +50mm and +150mm height is from stock.



If not, when work slows down one day I'll get there and get some answers.



As to is it legally binding, there's about 5 different threads here about it. Each state still has their own department of transport, but to my knowledge all the states have agreed to use this. Some have suddenly got very vigilant with it.

Things to remember though:

1) It doesnt override any pre-existing engineering approval though.


2) The mods that can be covered by this "code of practice" are not necessarily the only set of engineering options available to you.

[-Scott-]

I found an interesting document here.

TASMANIA

TYRES

Overall Diameter

For off-road passenger or commercial vehicles , The overall diameter of the wheel and tyre combination must be no more than 50mm larger and not more than 26mm smaller than that of any tyre designated by the vehicle manufacturer for that model.



A.C.T.

Refer to Tasmania

Current Regulations - Quoted from "National Code of Practice for Light Vehicle Modifications " (NCOP), Section LS, Part 4.

SOUTH AUSTRALIA

Refer to Tasmania

Current Regulations - Quoted from "National Code of Practice for Light Vehicle Modifications " (NCOP), Section LS, Part 4.

WESTERN AUSTRALIA

Refer to Tasmania

Current Regulations - Quoted from "National Code of Practice for Light Vehicle Modifications " (NCOP), Section LS, Part 4.



National Code of Practice for Light Vehicle Modifications

The Federal Government is currently attempting to get all states and territories to adopt this code, which includes regulations for alternative wheels and tyres, in Section LS, Part 4.

Currently Tasmania, South Australia, A.C.T., and Western Australia have adopted this code of practice. The current regulations for alternative wheels and tyres for Queensland and Victoria are very similar to those included in the N.C.O.P. for light vehicle modifications.

Obviously, this is from a tyre supplier, not a government web site, but I believe it's an indication of what's coming. For those considering new tyres it may be worth persevering with state transport authorities to obtain clarification of if and when they will come into force.

How will this be implemented? I don't know. But I guess (hope? ) it will all revolve around generic tyre sizes rather than specific manufacturer/"model" of tyres, and I also hope that whoever is checking this stuff is "reasonable."



OK, I can dream. But I like Toyo's OPAT specs, because they list 285/75-16 as being 49mm larger than 265/70-16, which was standard fitment on some Pajeros. Hopefully, if you can demonstrate that the change in size meets the regulations for at least ONE brand of tyre, then they should accept the larger size as an appropriate substitution, regardless of manufacturer.

Realistically, some officious little Nazi (Mr Scruby, for instance) will refer to his own set of tables, and stick rigidly to the limit - 50mm is safe and dandy, 51mm = horribly dangerous death trap.

My 2c,

Scott

[Syzygy]

were there any changes made to the code after the period for public comment ended?

I know there were lots of letters sent but I havn't read of any changes anywhere.

[Beastmavster]

Nope. I got no response back about my comments when it was open for public input.

I mainly was asking for them to clarify some of these issues BEFORE it was adopted. Sensible stuff to make the laws easier - not to mean I could run 38"s.

I think honestly they'd already decided what they wanted in it. That's the usual way it's done.

[gu4800]

I think honestly they'd already decided what they wanted in it. That's the usual way it's done.

So is this thing actually in?

Anyway, I'm gunna ring DOT on Monday and see if I can't get some info on it. Wish me luck?

Actually, on second thought - would any of the local "approved inspectors" - you know, the private guys who DOT approvals - would they know?

I'll ask my local mechanic mate - he knows some of the private certifying guys.

Will let you know if I get anything constructive!

[Beastmavster]

I think the vagueness of the tyre size issue is something you'd probably want the answer from the DOT itself.

Any information is better than none though.

[Shadow]

I think the vagueness of the tyre size issue is something you'd probably want the answer from the DOT itself.

Any information is better than none though.

The DOT and RTA and most governing bodies (police) use the Tyre and Rim Association Manual to determine the size of the tyre that was meant to be fitted to your vehicle (tyre placard) then they add 50mm and if your tyre measures more than that your pinged.

[Beastmavster]

Except some designated tyres can exceed those specifications already, even from OEM manufacturers.

[bogged]

give up....

[GUJohnno]

From a Yahoo Group

...i did manage to get an email from
the team leader of a vic roads division.hope it helps everyone.

Chris

You may lift the suspension by no more than 50 mm provide you retain
at least 2/3 of the original suspension travel in either direction,
flexible brake hoses are still of adequate length and drive shaft angles are
not outside their usable range. You may fit tyres up to 33 inches in
diameter (eg normal size is 31 x 10.5, you may go to 33). Together this will give a total lift of about 75 mm. You may need to correct your speedo as your indicated speed with these tyres may be slower than the vehicle's
actual speed leading to speeding fines.

Gray Scott
for Team Leader vehicle Standards

[cj]

That's what I have been told also in Vic.

If you want to know your starting base measurement for lifting then go to http://rvcs-prodweb.dot.gov.au/pls/wwws ... ify_Search and type in the Approval Code from the plate on your firewall and set "Status" to ALL. There you will find the specs e.g. stock suspension height, tyres etc. as the vehicle was supplied for approval for sale in OZ.

[Syzygy]

whats this approval code look like?

I cant find a bundera on that site

[blkmav]

That's what I have been told also in Vic.

If you want to know your starting base measurement for lifting then go to http://rvcs-prodweb.dot.gov.au/pls/wwws ... ify_Search and type in the Approval Code from the plate on your firewall and set "Status" to ALL. There you will find the specs e.g. stock suspension height, tyres etc. as the vehicle was supplied for approval for sale in OZ.

There's no GQ on that site

[cj]

That's what I have been told also in Vic.

If you want to know your starting base measurement for lifting then go to http://rvcs-prodweb.dot.gov.au/pls/wwws ... ify_Search and type in the Approval Code from the plate on your firewall and set "Status" to ALL. There you will find the specs e.g. stock suspension height, tyres etc. as the vehicle was supplied for approval for sale in OZ.

There's no GQ on that site

There's stacks of them. Just type GQ in "Marketing Model" and set "Status" to ALL and hit Search.

[Shadow]

Except some designated tyres can exceed those specifications already, even from OEM manufacturers.

of course they can, but not by 50mm...

[Beastmavster]

actually they do, that's part of the problem. Once the exception is made....

[Syzygy]

I believe the tyre and rim association allow a 3% variation either side of their stated diameter for a certain size tyre. The 3% only applies to the rubber section though and doesn't include the diameter of the rim.

so for eg. if the tyre and rim assosiation state a 31" tyre is to be 781mm on a 15" rim. 3% of the rubber area is 12mm, so a tyre can be between 769 and 793mm and still badged as a 31" tyre. I guess this allows for small variations in manufacturing.

This was talked about in great detail on the overlander forum last year sometime and I believe the RTA confirmed that it was ok to include this 3% in the max sized tyre you can fit to your car.

So if a car came stock with 31's, you can go 62mm (50 + 12) bigger, up to 843mm. I could of course be wrong though, just what i remember.

[DamTriton]

"...You may lift the suspension by no more than 50 mm provide you retain
at least 2/3 of the original suspension travel in either direction..."

2(either direction) x 2/3 = 1 1/3 times the original suspension travel "at least"!!!

There's a blooper they didn't see.....

[cj]

"...You may lift the suspension by no more than 50 mm provide you retain
at least 2/3 of the original suspension travel in either direction..."

2(either direction) x 2/3 = 1 1/3 times the original suspension travel "at least"!!!

There's a blooper they didn't see.....

or....

originally have 60mm travel one direction and 60mm travel the other way so you have 120mm travel in total and 2/3 of 60mm is 40mm so as long as you still have 80mm (40mm x 2) of travel you are fine.

[blkmav]

That's what I have been told also in Vic.

If you want to know your starting base measurement for lifting then go to http://rvcs-prodweb.dot.gov.au/pls/wwws ... ify_Search and type in the Approval Code from the plate on your firewall and set "Status" to ALL. There you will find the specs e.g. stock suspension height, tyres etc. as the vehicle was supplied for approval for sale in OZ.

There's no GQ on that site

There's stacks of them. Just type GQ in "Marketing Model" and set "Status" to ALL and hit Search.

Thanks, PEBKAC

[bazzle]

That's what I have been told also in Vic.

If you want to know your starting base measurement for lifting then go to http://rvcs-prodweb.dot.gov.au/pls/wwws ... ify_Search and type in the Approval Code from the plate on your firewall and set "Status" to ALL. There you will find the specs e.g. stock suspension height, tyres etc. as the vehicle was supplied for approval for sale in OZ.

There's no GQ on that site

There's stacks of them. Just type GQ in "Marketing Model" and set "Status" to ALL and hit Search.

Very helpful.

Thanks

Bazzle

[Charlie]

I was having a squiz at the new NCOP (National Code of Practice) for light vehicles and came across this.

Don't know if this has been covered here before, but does anybody having anything else constructive on this?

(Says 4wd's can go 50mm bigger than standard in tyres - at least that's how I interperet it). The "Bulletin" is dated 1 Feb 2006.

It also says something about it being used in conjunction with the relevant jursidiction, etc, etc.

Comments welcome. Anyone have experience with the new "code" - is this now a national overriding code? If not, why have it if the states then have different rules.

Thanks, and keep it constructive.

Generally speaking federal overrules state which overrules local, for example damming the Franklin River the Federal Government said no and the high court agreed.
Practically speaking this means the State would have a hard time not adapting this code of practice as a minium safety standard but they can still implement stricter regs for example they can still say no tyre size increase..This seem to be the way QLD wants to go but I believe NSW will adopt the National Code.

Regards Charlie

[j-top paj]

maybe i should keep the paj??
at least it comes standard with 32s so running 33s is still legal

[Shadow]

I was having a squiz at the new NCOP (National Code of Practice) for light vehicles and came across this.

Don't know if this has been covered here before, but does anybody having anything else constructive on this?

(Says 4wd's can go 50mm bigger than standard in tyres - at least that's how I interperet it). The "Bulletin" is dated 1 Feb 2006.

It also says something about it being used in conjunction with the relevant jursidiction, etc, etc.

Comments welcome. Anyone have experience with the new "code" - is this now a national overriding code? If not, why have it if the states then have different rules.

Thanks, and keep it constructive.

Generally speaking federal overrules state which overrules local, for example damming the Franklin River the Federal Government said no and the high court agreed.
Practically speaking this means the State would have a hard time not adapting this code of practice as a minium safety standard but they can still implement stricter regs for example they can still say no tyre size increase..This seem to be the way QLD wants to go but I believe NSW will adopt the National Code.

Regards Charlie

actually in this case it works different

the federal rules could be considered the ADR's

where as state have thier own set of rules and relaxations modifications etc.

I think the NCOP will definantly come in as most DOT and RTA officers are as pissed off as we are about the differences in legeslation, at least tje few i have spoken to are.