Cert rules mean 33x12.5 tyre won't pass on 15x8 wheel

[Slideways]

Found out yesterday that the latest rules (well recent at least) specify that 33x12.5 tyres require at last 8.5" wide wheels.

Link here:
http://www.lvvta.org.nz/documents/infos ... _Guide.pdf

It doesn't actually list 35's...

Which means that 15x8 steelies are no good (unless beadlocked I guess).

15x8.5 is pretty rare so most people are going to have to use the common 15x10's?

I have three sets of wheels but none are wide enough so I am on the look out for something suitable here:
http://www.offroadexpress.co.nz/Forums/ ... 15&t=39192


Any help with sourcing something would be appreciated.
I do have some brand new 15x8 steel wheels but they are no good either.


Cheers

[CLUMZ1]

Shit, thats news to me, Safari runs 35x12.5 on 15x8's. Going for cert soon also.

[kbushnz]

Before you race out and replace all those rims... Talk to your cert man first...
It is a guide... not a rule...

[Slideways]

Before you race out and replace all those rims... Talk to your cert man first...
It is a guide... not a rule...

Unfortunately this is directly from the failure sheet, cert check was done yesterday.

[Ant]

Also check the tyre manufacturers recommendations, I think most will say 8"-10" rims for 12.5 wide tyres........... I know you have said it has come straight out of cert man's book but if you can come up with some evidence it might help, surely the manufacturer will know better than a rule book............not much help for your search for 10" rims sorry, but my 2 cents anyway

[Ant]

your link does state the following "tyres
must be an appropriate selection for the type and width of wheel to which they are fitted"

and "Additionally, where an LVV Certifier is presented with a wheel & tyre combination which is outside the scope of the tables in this info sheet, LVVTA requires that the guidelines of the tyre manufacturer in question are followed, and verification from the tyre manufacturer is provided by the LVV Certifier when forwarding the LVV plate application"

It does also state in a few places that it is a "guide". I think if you get enough info and maybe a letterhead from your tyre manufacturer you might be ok with 8"............this is of course if the manufacturer recommendation is 8"

[Henry]

Hi

I also had my cert fail on this.

In my case the tyre Manufacturer said 8 1/2 to 12 inch rims....

The certifier is just sticking to the manufacturer requirements

Henry


Henry

[Gardengnome]

So what happens if you have manufacture "A"s tyres on for the cert and they say its all good for 8" rims and you get a cert with 8". Then later you change to a different brand who recommend 8.5" minimum but no one mentions this when fitting or you fit them yourself? Makes mentioning the rim width on the cert plate a bit of a joke.

Should really mention "tyre manufactures recommendations for rim width adhered to"

Might not fit on the cert plate though.

[Slideways]

Damn, manufacturer is also 8.5" minimum.

http://www.gtradial.com.my/gtradial/mal ... 012&flag=3

Will have to see if its in option to change to different 33" tyres since I planned to anyway.

[kbushnz]

You can also explain to your cert man that the next size rim is a 10 inch... It in itself will pose issues when fitted.. It could contact suspension components as it is too wide...Then you may need to fit "Wheel adapters " to get clearance.... That's another issue...
Also when used off road it wont apply enough pressure to the bead and may cause your tyre to roll off the rim. That itself is a safety issue...
Lets face it you are talking 1/2 an inch....

Good luck !

[Slideways]

Just found specs for both Khumo KL71's and BFG KM2's are minimum 8.5"

The certifier is into 4wd's by the sounds of it but is sticking to the rule even though it is a bit silly and he has argued it with the powers that be.

[CLUMZ1]

Someone loan this guy some 33"s on 8.5"s!! What a pain in the arse over a nonsensical "rule".

[gismo]

the rulings are crazy. my brothers surf has cert for 33s on alloy rims. but the plate only states alloy rims.
whats up with that.

[evilknieval69]

Just don't cert it for the wheels. Put standard sized wheels and tyres on for the cert and change afterwards. If you didn't have other items requiring cert then you wouldn't take it in just to cert the wheels and tyres would you.....

[Slideways]

Just don't cert it for the wheels. Put standard sized wheels and tyres on for the cert and change afterwards. If you didn't have other items requiring cert then you wouldn't take it in just to cert the wheels and tyres would you.....

I think technically 33" tyres need a cert due to being more than a certain percent larger than factory. Can't remember if that is specifically just the tyre size or if its because it will make the speedo inaccurate.

So since I'm forking out the $460 for a cert I wanted to get it done with 33's so I don't get another wof issue (unlikely but would be annoying and expensive if it did).

EDIT: looks to be a 5% threshold for tyre size difference so 31" to 33" is almost 10%.

[muddy]

Borrow some 32's for the cert then your 33's will be within 5%

[tallsam66]

On cert plate it will only mention the rim size ... not the tyre size.

[wjw]

On cert plate it will only mention the rim size ... not the tyre size.

But the tyre size will be in the system..... my paperwork states the tyre size, make, model and rim info.

[CLUMZ1]

Bizzare that they care so much... go and buy a 2013 Hilux on 16" rims with 31"s, then buy some steel wheels in 15" with 31"s and you DONT need a cert... why do they care about rim width/model?!

[Crash bandicoot]

It must be said though....fitting a 12 and a half inch tyre to a 8 inch rim is a bit of a squeeze really. I've got safari rims with a 10.5 inch tyre and that's fat enough any more it'd be like driving on jello with all the side wall movement.

[luckyme]

Just found specs for both Khumo KL71's and BFG KM2's are minimum 8.5"

The certifier is into 4wd's by the sounds of it but is sticking to the rule even though it is a bit silly and he has argued it with the powers that be.

Does the width marked on your rim? I have custom made 8"ones, might try to push them through cert as 8.5"

[Heath]

Just don't cert it for the wheels. Put standard sized wheels and tyres on for the cert and change afterwards. If you didn't have other items requiring cert then you wouldn't take it in just to cert the wheels and tyres would you.....

I think technically 33" tyres need a cert due to being more than a certain percent larger than factory. Can't remember if that is specifically just the tyre size or if its because it will make the speedo inaccurate.

So since I'm forking out the $460 for a cert I wanted to get it done with 33's so I don't get another wof issue (unlikely but would be annoying and expensive if it did).

EDIT: looks to be a 5% threshold for tyre size difference so 31" to 33" is almost 10%.

Check what tyre sizes came with the vehicle from factory. Some vehicles come with varying sizes from factory depending on the market and country. You might find something from the factory that had 32's or there abouts (265/75/16 were about 32 high). How about looking for a tyre based on the width of rim and working back? Its a bit ass about faced but might work, or see if you can hire some 8.5"s

[tallsam66]

I note at the bottom of the LVVTA document they acknowledge assistance by Goodyear & Dunlop Tyres & Dave Hadley Tyres Lower Hutt .
Id be interested to know what mechanical engineering qualifications these organisations have.
If there is something I have learnt if the people who say technical stuff don't have the correct & relevant qualification what they say is worthless.

Also has this information been peer reviewed to ensure the information is credible.

[mck]

Ok I got a cert 4 years ago with 13.5 mudzillas on 15x8 rims, does that mean I need to re cert to meet new laws..?

[shortylux]

No, it means that dumb new "laws" (suggestions?) have come in, but they don't back date. IE new cars need to meet emission standards that old cars don't.

[mck]

Yeah that what I thought, so if I have gone to a 12.5 tyre would it still meet my cert ? Given it less width that when certed

[Heath]

How about 33x9.5 tyres? Gives you the height, they will be fine for the rims too.

That way you have the rims on the cert and 33 inch tyres as well.

Could be wrong but worth a thought.