Rim width and certification.

[Disconewhere]

This seems to be a tricky one.
I've got a set of 35x12.5x15 MTRs that I want to run on 7 inch rims on my Defender. I also want to have it certified but the certifier is telling me that 7s are too narrow, has any one had any problems with running 12.5 tyres on 7 inch rims? It's outside the recommended rim width for the tyre but I haven't had any problems with my current set. I'm thinking that I may end up having to take it for a cert on some 8 inch rims then swap back to 7 inch rims afterwards.
Anyone in/arround chch have some 15x8 LR rims I could borrow?

Cheers for your help guys.

[albundy]

I ran big tyres on 7" rims back in Oz, was a little unstable on road, felt as if it was rolling side to side. Just remember your insurance clauses if you are using rims not certified for your truck.
Al

[Disconewhere]

Cheers for that Al, your right, insurance etc becomes a problem. At the end of the day a piece of rubber that big wrapped around any 15 inch rim is never going to handle that great, especially when you consider high centre of gravity etc, but it's not going to be driven like a race car on the road so I will never realistically cause a problem.
It's rather unfortunate that legality and safety aren't necessarily related, if it were to be unsafe I wouldn't do it but I can't see that it is.

[nstg8a]

This seems to be a tricky one.
I've got a set of 35x12.5x15 MTRs that I want to run on 7 inch rims on my Defender. I also want to have it certified but the certifier is telling me that 7s are too narrow, has any one had any problems with running 12.5 tyres on 7 inch rims? It's outside the recommended rim width for the tyre but I haven't had any problems with my current set. I'm thinking that I may end up having to take it for a cert on some 8 inch rims then swap back to 7 inch rims afterwards.
Anyone in/arround chch have some 15x8 LR rims I could borrow?

Cheers for your help guys.

does the cert plate actually mention tyre size though?

mine only mentions rim size, nothing about tyres at all.....

[albundy]

Your tyre size is not on the cert plate but is in the system when it is certed. That way when you come for a warrant, you can't cheat the system. If at the time of certifification you have 35's on, it will go into the system. When you go back for a warrant and they check the cert plate details in the system and you have 37's on= failed warrant. If however you go back with 33's on=all OK. This is how it was explained to me by my warrant guy, as I now need to go for recertification as I have longer suspension and running 35's.
Al

[nstg8a]

Your tyre size is not on the cert plate but is in the system when it is certed. That way when you come for a warrant, you can't cheat the system. If at the time of certifification you have 35's on, it will go into the system. When you go back for a warrant and they check the cert plate details in the system and you have 37's on= failed warrant. If however you go back with 33's on=all OK. This is how it was explained to me by my warrant guy, as I now need to go for recertification as I have longer suspension and running 35's.
Al

so how would i find out what my truck is cert'ed for?
im guessing since it is certed for the 15x10s, and used to run 33's it will hopefully be sweet, but who knows...

[Bulletproof]

I would be very careful. In the NZ 4 wheel drive ass. mag a couple of months ago there was an article about tyres and certification. This Guy tried to get certified on 35s and didnt pass the brake test so went home and put smaller wheels on.
He now passed the cert. so went home and changed back onto the 35s.
While driving on the road was involved in a fatal crash and the police were talking about a manslaughter because the truck was not road legal.
Look at there website under " Low volumne vehicle technical Ass" Everything is there about cert.
Richard

[albundy]

Is that the police website or the LTSA website Richard.
Al

[Bulletproof]

Hi Al Any thing you need to know about mods ar anything that is allowed on vehicles is under LVVTA on the web.
The article was in "trail Torque" Im not sure which month, as I have thrown the mag away.

AS a side point have booked a cabin at ikamatua on 18-19 july.

Richard

Is that the police website or the LTSA website Richard.
Al

[xj]

Your tyre size is not on the cert plate but is in the system when it is certed. That way when you come for a warrant, you can't cheat the system. If at the time of certifification you have 35's on, it will go into the system. When you go back for a warrant and they check the cert plate details in the system and you have 37's on= failed warrant. If however you go back with 33's on=all OK. This is how it was explained to me by my warrant guy, as I now need to go for recertification as I have longer suspension and running 35's.
Al

so how would i find out what my truck is cert'ed for?
im guessing since it is certed for the 15x10s, and used to run 33's it will hopefully be sweet, but who knows...

Ive got a sticker with the certifiers name and number, as well as the cert plate. All id have to do is call the certifier and get him to go back through his records, which he must legally keep, for the info regarding tyre size. Do you know who the certifier was?

[lanky]

Im just wondering how picky different certifiers may be, someone mentioned somewhere that if a rim isn't inside the tyre manufacturers specs you wont get a cert.

I'm looking at getting 33x12.50 or 35x12.50 MTRs, and their specs say 8.5 - 11inch rims, so that would mean you could be failed if you had these tyres on 8inch rims, is this right?

[Petemcc]

best way to find out is to give your certifier a ring. Part of this topic annoys me. What is the point of getting a cert if you are going to go home and change your wheels and such like. If you change them after your cert then it is no longer legal and you just waisted $400 odd on a cert.

Pete