canter rims

[alan]

I'm not a 100% sure but I think the back axle carrying capacity is reduced, so if your truck weighed 2.5 tonne you could carry 3.5 tonne on the back, derated to 4.5 tonne would reduce this to 2 tonne which for most campers etc is plenty.

[blackduck]

strange as it may seem but my swb is derated to 4.5t in qld my compliance plate is unchanged WRT Tare & GCM the only change is GVM
so with loaded truck and van in tow im good for nearly 9.5t
as nothing on the truck has changed WRT suspension etc this makes perfect sense - its pretty much all acedemic
not sure if this is the done thing but who am i to argue with captain bligh and her licensing dept
so i do as my compliance plate advises

[westyss]

Besides compliance with the law, I think just the fact that tire ratings become a factor in what can be installed on a 16" rim, the reason most are now going to a 19.5" are to achieve single tire use instead of duellies with enough capacity for the load, and as we all know, rigs get loaded (or overloaded ) all the time, so just derating a truck is one option, but is it a good option? plan ahead and use a tire applicable to a realistic load (or overload ), if a 16" rim and tire are Ok , go for it, but most will say go to a tire with extra capacity just in case its overloaded with a strong enough tire to go into the bush and not have issues, a higher load rated tire as stated previously will stand up to more abuse than a lower rated tire, no? I looked long and hard at tire/rim options and why re-invent the wheel, do what has been proven to work, or at least is given the green light to work, ie, the ATW 19.5 wheels that have been tested and work. If Alan was to get a 19.5 rim then all is OK and no issues, even though a 16" rim with a proper load rated tire would be more desireable. So we have one or the other
1) New 16"tire with proper load rating (doesnt seem to exist)
2) 19.5" Aluminum bling rim to accommadate proper rated tires for these trucks.

When I was looking I sure would have gone for a 19.5 Al rim, seems like a perfect fit. I think Bajaroad did the 16" rim , cant remember the tires used but he could maybe shed some light on servicability of the tires with camper on.

[westyss]

Out of curiosity I looked up toyo MT tires, I think Bajaroad had the LT315/75R16 127Q load rating, which is around 4000 lb I think, also have a LT385/70R16 130Q over 37" in diameter and wide, like 15", would these work ? does anyone have a load weight for 127 and 130? They are both a 16" rim.

[westyss]

All I found was with a load index of 130 = 1900kg or4180 lb.
127 load index = 1750 kg or 3850 lb.
enough??

[alan]

I spoke to Kumho tyres today they have a shipment of 315/75/16 tyres with a load rating of 127 arriving in 3-4 weeks.

[Bandicoot]

There are definately options for 4.5 and 6 tonne vehicles using super single wheels with rims smaller than 19.5 inch.
My EarthCruiser came standard with Michelin XZL 255/100 R16 which are rated at 1700 kg at 110 kph. My EC runs almost exactly 50/50 front rear axle loads so I could have a GVM of up to 4 x 1.7 = 6.8 tonnes based on tyre loads. Of course, the FG front axle is limited to 2.6 t and the rear to 4.3 t, so tyres rated at 1.7 t each is more than sufficient for the front axle and with a GVM of 6 t and 50/50 load distribution, there's not much point having a rating that much more than 1.5 t per tyre on the back.
I am currently running Hankook 37x12.5R17LT tyres (on 17 x 8 inch rims) rated at 129Q which means 1800 kg at 160 kph. Even apart from the GVM, my EC at absolutely full load with 1/2 tonne of water and fuel on board, full expedition equipment and supplies for a few weeks of unsupported travel, etc (plus wife) runs at about 5.2 t. So 1700 to 1800 kg tyres have a very ample margin already.
Both the Michelins and Hankooks have their full load rating at 65 psi and since I run much lower than 1700/1800 kg, I can (and do) run the tyres at around 50 psi cold. This is also what both manufacturers recommend for this tyre loading.
And this is where this type of tyre really comes into its own. For any given suspension, a tyre running at 50 psi has a much larger (double?) footprint on the ground than a 19.5 inch tyre (typically running at 90 to 110 psi for the same load). This means much better adhesion to the road surface so better braking and cornering. It also means a much softer better ride for the occupants.
Also, smaller rims means higher sidewalls (for the same overall tyre diameter) which gives much better "air-down" capability for soft-road, off-road and sand work.
I've run the Michelins at 12 psi hot to get out of a pickle. I doubt this could be done with any 19.5 inch tyre.
Finally, both these rim/tyre combos run at about 60 kg per wheel. This is manageable for most adult males. A 19.5 inch wheel is more like 80 kg per wheel; this is a real safety and manual handling exercise and also requires that much stronger spare tyre carrier, etc.
Rick

[blackduck]

hi rick
so what sort of milage were you getting out of the 16's
and would you recommend minimising the loaded expo weight by leaving the wife behind

[bptp7270]

I'm confused with this derating business. I assume that the EC's are 4.5t, but do they have a new rating for each axle? It has been explained to me(don't know if its wrong or right) that the legalities require that your wheels and tyres on each axle are at least equivalent to that axle's rating and not just the truck's GVM divided by 2. In the case of the 6t truck it is 4.3 on the rear and even if you never get anywhere near this in practice, legally your wheel/tyre combo must meet this capacity. At least this is what I was told.
Anthony

[blackduck]

as far as i know de rating is primarily based on licensing requirements in a particular state (taking into account we have 7 sets of licensing legislation in this country)
the concept is being able to drive a load carrying vehicle on a common car licence by reducing the carrying capacity reducing the risk.
derating does not change the charachteristics of the vehicle unless you change the phyisical build of the vehicle
in my case my derated 4.5T swb canter still has all the running gear of the 6 tonner but now the dragon can drive it without the need for a LR licence
if i change the suspension and wheels / tyres (and believe me its going to happen) then the axle load rating will be determined by the choice of replacement parts and certified by an engineer
thats my take on it anyway