canter rims

[Amesz00]

Guys will air 19.5's down to whatever psi they have to, to get out of trouble. The problem with the 19.5's is the the tread ply and sidewalls are so much stronger (and puncture resistant as a result) that if they aren't reinflated after you get into trouble that running too fast for a given pressure can then generate excessive heat which can then cause tyre damage. So they can be aired right down but speed has to be monitored according to the set pressure. Granted, the speed can be much higher for an aired down XZL than a typical 19.5.

sorry john, but dont quite agree here. ive run my 11.00r16 michelins down to 10psi to get out of a mud bog. when the truck was out of the bog, the contact footprint was about 16" long.. any 19.5 rim would be well and truly on the ground by then.

also there is a lot more that comes into play with the size of the footprint, the amount of contact with the road and the "handling" of a tyre than just the psi........

definetly. IMO the biggest difference between 100R tyres and 19.5 tyres as far as road handling will be the slip angle. ie the angle of the tread/direction of vehicle travel to the angle the rims are pushing them. high sidewall michelins have a massive slip angle, due to the big soft sidewall. this (in theory) should make them more forgiving. the 19.5s will be much more solid, feel more responsive, and therortically will let go sooner (less elasticity in the tyre sidewall) BUUUT i think driving a truck on bitumen it would roll before any of this was reached.
Andrew

 

[Bandicoot]

re: pressures and loads in 16/17 inch versus 19.5 inch rims--


Well my friend could be mistaken although the table he showed me seemed clear. Nevertheless, I still struggle to understand how tyres that are rated at 2.9 tonnes each at 120 psi and are described by Toyo as being "low profile" (see pic) can possibly have the same high speed pavement running pressure as tyres that have a maximum pressure of 65 psi (assuming same axle loadings), and also how 120 psi max tyres can be "aired down" to similarly low values for soft-road or off-road or sand/mud work. I agree that if the 19.5 inch Toyos can run on bitumen at the same pressure (for same axle rating) as the Hankooks or Michelins, then they would have the same (or very similar) contact area.
I guess my concern was that the sentiments on the thread seemed to be moving towards the big and heavy 19.5 inch rims with very high rating low-profile truck tyres being the ideal solution for nimble off-road motorhomes.
I would also note that a standard 32 inch 4WD tyre and rim is about 45 kg, the Michelins on 16 inch steel rims are about 60 kg and the 19.5 rims and tyres are a whopping 80 kg per tyre. This is a major manual handling issue especially if you need to change a tyre by yourself in off-road conditions where the vehicle may not always be on a good surface and level etc. Also it means the spare wheel carrier must be that much stronger and heavier. Finally, the moment of intertia of an 80 kg wheel is that much greater than a 60 kg wheel, so more engine power is sapped merely spinning the wheels up during acceleration, and more braking effort used up in just slowing the rotating wheels down during braking.
I do accept that if the vehicle is too heavy for smaller rims and lighter tyres then these heavy ones are the remaining alternative.
On a more relaxed note, those living in the Brisbane area will no doubt recognise where we are at present!
Rick

 

[Bandicoot]

And just on sidewall height (at least one key factor in ability to air down before damaging either the tyre or the rim):
Toyo 285/70R19.5, sidewall 199 mm
Michelin XZL 255/100R16, sidewall 255 mm
Hankook 37x12.5R17, sidewall 251 mm
That means the Michelins and Hankooks have 25% more sidewall height than the Toyos.
Rick

 

[blackduck]

You guys are not making my life any easier
Im seriously looking at changing over to singles on my swb 649 to go with the parabolics im salivating over
originally i was sure 19.5's were the go
then I saw alans ally bling rims with andy's big 16's on
now im not so sure
im not sure about the rest of you guys but im certainly not getting any younger and the thought of handling an 80kg wheel myself doesnt give me warm fuzzies
also as i normally travel solo the need to air down to escape a situation places a lot of reliance in the capacity of the tyre
im counting on your knowledge and experience before i commit

 

[bptp7270]

Hi Blackduck,

Just checked out your web page and it looks great. Look forward to your future travel posts.

Anthony

 

[Bandicoot]

Stu
As I'm sure you're aware, that's the joy of forums. Plenty of advice but sadly no one to make the decision for us. Bit like an old-fashioned debate: hopefully as each of us hears the speakers for the affirmative & then those for the negative, we make a call and live with it. And there are times where I've changed sides mid-way through a debate...!!!
Rick

 

[whatcharterboat]

Well my friend could be mistaken although the table he showed me seemed clear. Nevertheless, I still struggle to understand how tyres that are rated at 2.9 tonnes each at 120 psi and are described by Toyo as being "low profile" (see pic) can possibly have the same high speed pavement running pressure as tyres that have a maximum pressure of 65 psi (assuming same axle loadings), and also how 120 psi max tyres can be "aired down" to similarly low values for soft-road or off-road or sand/mud work.

The Toyo chart gives the maximum tyre (not axle) load for 100-130kph and 65psi (example only) at 1696kg. (So that shows the load difference at pressure there) It then says that if you had to let them down to 22psi (and it gives increments all the way down from 120 to 22psi) then the maximum speed you could go travel at with that load of 1696kg would be 7kph. Maximum tyre load at 100 to 130kph at 120psi is 2790kg.....that's 5580kg on the axle!! Like I said, maybe you guys are looking at the chart as axle loads not tyre loads. It's a 3 way chart giving speeds, loads and pressures. So you dial in the load per tyre and it will tell you how fast you can go or how low psi you can go as an absolute minimum. There is plenty of other stuff in there that you'd need an enginneering degree to work out but that should give you an idea.

I would also note that a standard 32 inch 4WD tyre and rim is about 45 kg, the Michelins on 16 inch steel rims are about 60 kg and the 19.5 rims and tyres are a whopping 80 kg per tyre. This is a major manual handling issue especially if you need to change a tyre by yourself in off-road conditions where the vehicle may not always be on a good surface and level etc. Also it means the spare wheel carrier must be that much stronger and heavier.

Hey, I just spent all of last Monday checking out how our new 445 / 65R / 22.5" tyre/wheel package fitted up on the big 13 ton 4x4 Isuzus. You should try changing 4 of them by yourself even on a smooth concrete floor!!! Honestly, it's more technique than muscle and 2 levers under the tyre to locate it easily on the hub as you fit it up....... but you definitely need an automated wheel carrier. You can't go lifting a 19.5 on your own or a 16 for that matter.

Finally, the moment of intertia of an 80 kg wheel is that much greater than a 60 kg wheel, so more engine power is sapped merely spinning the wheels up during acceleration, and more braking effort used up in just slowing the rotating wheels down during braking.

Maybe in theory but that doesn't really show in test results. What does show is too great an increase in rolling diameter.

I do accept that if the vehicle is too heavy for smaller rims and lighter tyres then these heavy ones are the remaining alternative.

I reckon that a little overkill is better too........especially when it comes to punctures, hitting washouts, etc

On a more relaxed note, those living in the Brisbane area will no doubt recognise where we are at present!

Beautiful.

 

[whatcharterboat]

sorry john, but dont quite agree here. ive run my 11.00r16 michelins down to 10psi to get out of a mud bog. when the truck was out of the bog, the contact footprint was about 16" long.. any 19.5 rim would be well and truly on the ground by then.

11.00R's !!! Thats cheating. You win.

 

[Amesz00]

Finally, the moment of intertia of an 80 kg wheel is that much greater than a 60 kg wheel, so more engine power is sapped merely spinning the wheels up during acceleration, and more braking effort used up in just slowing the rotating wheels down during braking.

Maybe in theory but that doesn't really show in test results. What does show is too great an increase in rolling diameter.

i agree. i cant see a few extra kgs of rotating mass making any difference whatsoever to acceleration on a truck, and braking effect would be negligable. think of the power the brakes have to produce to slow a truck, then imagine the truck lifted by its axles, wheels spinning at 100 and the brakes applied. 20kg difference would make hardly any difference there, and thats without the enormous load of the truck resisting the brakes.
diameter would likely be a different story, my canter has 1100s that are about 980mm tall, its basicly unloaded (runs around 4-4.2t) and you can feel it has a massive effect on braking..

11.00R's !!! Thats cheating. You win.

*evil laugh* mwahahahaha

I reckon that a little overkill is better too........especially when it comes to punctures, hitting washouts, etc

mmmm.
think i mightve told this story before but oh well. when dad and myselft were up in the kimberleys in 2010, we went up to mitchell plateau. the road up there is quite corrogated, and has random rock 'shelves' strewn across the track. his MAN runs big 20" XZLs and my canter has 1100r16s. after a couple of minutes we decided it was too rough on the vehicles and let our pressures out to about 35. no more issues were had. a few days later we were on the way back to broome on the gibb, and heard of a tour coach broken down further up. it was a 14.280 MAN safari bus (built by coach designs, but we wont hold it against em ) that had been up to mitchell plateau a week before. it had snapped its front axle clean in half on the left of the diff. MANs are fairly famous for their strong axles, particularly fronts. we noticed the wheel setup on the truck was those 15r22.5 (think 385/something in new terms), the common truck super singles. the fella didnt seem to be overly knowledgable in 4wding things, and we soon found out his tyres were all at 80-odd-psi.
i propose that his axle breakage was almost soley due to the wheels setup on the truck, and the fact he had not let out the pressures. had it had 20" michelins, he most likely would have gotten away with not deflating (the ride would still be terrible), due to the tyres forgiving nature and the fact thats what they are designed to do.
this may seem harsh to 19.5 owners etc, but lets not forget that they are a truck, road tyre. not an offorad tyre.
dont get me wrong, id take 19.5s over 750 duals anytime, but for the work i do, if i choose between XZLs or 19.5s...
+ lets face it, a big set of XZLs is sexy as...

 

[SkiFreak]

Maybe in theory but that doesn't really show in test results. What does show is too great an increase in rolling diameter.

I must admit to being surprised to read this, but as is often the case... theory and actuality have been proven to differ on many occasions.

I remember from my cycling days (I used to ride 50-100Km/day) that one of the major things that made riding easier was to reduce rolling mass.
Reducing the weight of the wheels and using better tyres definitely reduced the amount of effort required to ride the bike.

I totally agree that rolling diameter has a huge effect. This is one thing that I believe many people upgrading wheels do not fully understand; or, if they do, they ignore it.
I am positive there are many vehicles on the road that no longer meet their vehicle's minimum safety specifications due to wheel upgrades.
How many users do a brake upgrade along with their wheel upgrade? Not many I am guessing.

 

[whatcharterboat]

this may seem harsh to 19.5 owners etc, but lets not forget that they are a truck, road tyre. not an offorad tyre.

Well that's true of almost all 19.5" tyres....the Toyo being an exeption. As Toyo claim, they are a M+S tyre (mud ' n ' snow). Obviously alot more biased to road than the XZL but still designed to provide traction in mud.

 

[Barrabindi]

Hi All,

Ive seen posts suggesting XZLs fitted to 16x 6" 6.5" & 7" rims. Michellin state 16 x 6.5" only.... does anyone have them fitted to 16x 8"??
In theory shouldnt a 255 wide tyre fit an 8" rim??

Thanks

 

[whatcharterboat]

Following on from a couple of weeks ago...just came across this pic today ..... these are Rural Fire Brigade trucks that only operate on the beach. They are both out to max axle loads (around 4500kg on the rear, I think) as they carry large water tanks, diesel pumps and all the usual paraphanalia. The truck on the left is a SWB Fuso FG and on the right is newer Isuzu NPS. They run 19.5 Kuhmo "All Position" tyres which are purely a road tyre (so useless in mud but very nice in sand) ..... and this is what they look like down at 20 psi.

As a side note, If these things ever come up for sale .... wow. Absolutely meticulously maintained, spend 99.9% of their life sitting in a sealed shed, and the last time I looked at the 2001 model FG 637(in the pic), it had just clocked up a whole 3000kms on the odometer!!!

 

[Barrabindi]

Hi Canter drivers,

Thought you might like to see another Canter joining the ranks. Not really a camper, but a "bush bus".

Im very impressed with the ride of my new singles.
Suspension upgrade from Cairns.
16x8 rims from Melbourne.
Tyres from "Tire Rack" USA...... Goodyear Duratrac 315/75x16 127Q.

Only tested on highway and paddocks, Cape York test this week.

a couple of pics

 

[offroadpup]

Hi Canter drivers,
Im very impressed with the ride of my new singles.
Suspension upgrade from Cairns.
16x8 rims from Melbourne.
Tyres from "Tire Rack" USA...... Goodyear Duratrac 315/75x16 127Q.

Only tested on highway and paddocks, Cape York test this week.

I am similarly impressed with these tyre so far but as with you have not put it over anything rough yet. Can only describe the side so far as smoooooth.

Can I ask what pressures you are running in them on the highway ? Did you find a decent pressure-to-load chart for these tyres anywhere ? I've not looked for one yet, just put 50psi in them for now and have been running around the Gold Coast getting stuff done.

Good luck with the cape run, keen to hear how they perform.

Rgds,

-Andy