Member - Barry C (NT) replied:

Steve

You need to look carefully at the tyre load capacity, you don't give the GVM (not what it has now front and rear but what is on the compliance plate is the key) and maximum axle load either from compliance plate so hard to be too specific.

I have been through the exercise prior to writing a contract for either a Canter or Isuzu and super singles were a signifciant problem up to about 6 tonne GVM on both cab chassis, and we could not proceed with suple singles legally.

I think it was axle load capacity versus tyre load capacity, ie the tyres were not rated to carry the axle load. IF you do find a super single rated to the load capacity you require try to ensure it is not running at max load capacity all the time - ie have a margin for safety.

As an example if 6 tyres had 1000kg rating, the load capacity of the TYRES on the rear axle is 4 tonnes, HOWEVER when you fit super singles ie 2 tyres only they need a load capacity of 2 tonnes each and this is the problem. For the rim size of many small trucks the load capacity is not (to best of my knowledge achievable - but I stand corrected if anyone knows a product that will comply.)

Anyway heads up to check this and tyre dealers should be able to help.

Cheers Barry

smort replied:

Hi Steve

give bridgestone sydney HO a ring - get ready for a bit of a wallet shock though - wheels and tyres for my isuzu abt the same gvm as your mitzi (have to have a u show me yrs and I'll show u mine) - abt $1200 per wheel a few years ago. They will arrange the whole deal or you could source your wheels separately from a wheel maker - sankey comes to mind - but it is a chicken and egg exercise - the wheel must fit the tyre and tyre must fit the wheel - I suppose at the end of it u have to source a tyre first and then a wheel to suit for the mitzi. I have two spares which ups the anti a bit too.

The duals on the rear sure can be a pain - checking them - and if you are like me (read most of us) dropping pressures on dirt and more on sand - an extra set and getting onto the inner valves etc - if you have got this pressure up pressure down problem solved I would like to hear from you. They are also a pain from a practical point of view the track at the rear is different from the front which causes tracking problems on loose dirt and gravel and of couse sand.

Hope this helps

SMORT

johnsie replied:

We made up a 8 lead tyre inflator for airing up and down out of abit of steam pipe with 5mm plate welded into the ends and tapped air fittings in for supply with a tap to let air out and 8 leads with the clamp on valve ends and a pressure gauge.It hooked into the trailer supply.Only a couple of hrs work but very easy to make.

Member - Rod M (NSW) replied:

Hi Steve,
if you need rims then try Mullins (CSA) wheels or Titan wheels, both in Sydney, I am looking at the same thing only on a larger scale for the Hino. Be prepared for the cost, it won't be cheap. $450.00 a rim is the cheapest I can find to have them made so far. To be compliant with the weight of the truck you may need to go bigger in overall diameter to find the right tire.

We should have a get together of the larger trucks for an idea swapping night.

Member - John A (SA) replied:

Hi Steve
Just a note to beware of decreasing drive axle legal mass when fitting super-singles.
Had a problem in SA several years ago when we fitted supersingles to a 6 x 4 Louisville. The maximum we were allowed over the drive decreased from 18t to 15t.
I know this is different to your situation but beware if load carrying capacity is an issue.
Regards
John

Member - Jerry C (WA) replied:

Hi Steve,
I had a quick look at a new dual cab 4x4 Canter in Perth this morning which has just had a caravan / office type body built on the back, with a roof rack on top it is 3.1 metres high and weighs 3750 Kg empty and chassis is rated at 5500 Kg.
It is fitted with four singles, I think 285 x 70 R 19.5's tubeless, which are rated at 4000 Kg each. Rims are made to spec some where in the east.
A single cab very similar style of vehicle has been used by a tour operator in the Noth West for some years and according to one of the former drivers they perform very well.
Cheers and good luck

Jerry