Tyre sizes?

[Tom D]

Anyone know if the on board computer will be programmable for tyre sizes to keep the speedo accurate? Or even better will different diff ratios be available?

This one on the South Africa demo circuit looks sooo much better with larger tyres. The standard model looks under tyred to me… First thing I do when i get mine will be fit some bigger tyres…
 

 

[DenisM]

The vehicle is not only sporting bigger tyres but non-standard wheels as well.... ?
I can imagine that the increased weight of that combination will certainly test the rigidity of the rear door when the vehicle is driven over rough corrugated roads...

 

[Tom D]

I notice the spare is just the standard BFG.. 
I saw the other thread on tyres after I posted this, seems like there is the option to go to 33 which I would definitely do.

 

[@nd]

Just been looking at how much BFG's KO2 tyres weigh, raised white lettering add about 10% to the tyre weight.

 

[Shaky]

Must be very think paint then !!

I wonder why that adds 10%. Time will tell but I hope we don’t end up with rear doors dropping over time. I reassure myself that the same problem on the old LR is so well known that the Ineos designers have thought about that one a long time ago. 

 

[stickshifter]

The door hinges on the Grenadier look strong. Maybe we can get some input from Ineos on the weight capacity of the spare carrier.

A relatively easy option for aftermarket producers (if they are inclined) is a bumper-mounted swing-out carrier like the one below. I've used similar products in the past, and they have worked well. The two downsides are cost (often a new rear bumper as well as the swing-out tire carrier), and weight (steel bumper, steel tire carrier, plus the larger tire).

 

But other options might emerge in the aftermarket if the Grenadier sells well, and maybe some aluminum products will be developed. Gotta keep weight down as much as possible. An example is GenRight - an American firm specializing in aluminum Jeep parts, like this tire carrier below:

 

 

[DenisM]

The inclusion of an optional exterior "utility belt" on each door required strengthening of doors and frames etc. I've seen commentary on this which mentions the additional load on the door of up to 150kg max. That's static... so the increased dynamic loading of a "weighty"  35"  tyre on a steel rim should mean that that the hinges won't tire!?? (Dad joke sorry!)

 

[Ferrugenfish]

[QUOTE username=Tom D userid=9001460 postid=1332888672]I notice the spare is just the standard BFG.. 
I saw the other thread on tyres after I posted this, seems like there is the option to go to 33 which I would definitely do.[/QUOTE]

I don't think the spare tire location allows for a 35" tire due to how close to the rear left door it would be - it would likely hit the tire before it can open.  This was mentioned in another thread... probably an easy fix with an aftermarket tire bracket.  I wouldn't be surprised if Ineos offered one in short order too.

 

[klarie]

Reading all this - and I am "just a normal hunter" locally and definitely not intending to do overlanding in Australia, Africa or elsewhere - perhaps travelling Scandiavia, Somewhat the baltic course from Helsinki all way north directing then south again to malmö / Öresund and then back. However was never considering I would need larger offroad tires.
What bugs me - I tried to find the specs of such tyres. wheel rim diameter seems the same as normal tires - eg 17" but the sidewall is wider than usual 80% of tread with. (standard tyre)
Modern tyres have mostly a low sidewall - 60% 50% or less - on sportscars tyres. - what is the sidewall measured on these large offroad tyres? Couldnt find any definitions on that.
I d like to see an IG with standard tyres and a 35" tyre mounted on wheel next to it (unmounted ) to see the effect in direct comparison.

Although my dad was a car mechanic - and grew up with cars - I am far away from this specials. To me the IG will be first of all a hunting and towing vehicle (there is not much wilderness left in Germany and surrounding areas. and if there is any - it is most certainly not permitted to drive a vehicle there. )

 

[Rab]

Standard tyre size is 265/70 17 or 255/70 18

 

[Krabby]

Standard tyre size is 265/70 17 or 255/70 18

Which is about 31.7”/804 mm and 32.1“/815mm respectively.

 

[klarie]

So the 35" will have a greater outer diameter on same wheelsize.. what is the size / length of the sidewall between tread and rim of wheel then calculated
same size as tread width? It is significantly more.
To those of you who are experienced offroaders - during offroading - tyre pressure is reduced to increase traction (obvious)
However what is average normal pressure in such tyres when on rather hard ground or rarely on road / gravel - when reduced pressure is not required?
Had once ( a couple of years ago) the chance to sit in an argo atv 6 wheel - driven by sticks like a tank.. they are equipped with special low pressure tyres just 0.3 bars / 4.35 psi

 

[ECrider]

So the 35" will have a greater outer diameter on same wheelsize.. what is the size / length of the sidewall between tread and rim of wheel then calculated
same size as tread width? It is significantly more.
To those of you who are experienced offroaders - during offroading - tyre pressure is reduced to increase traction (obvious)
However what is average normal pressure in such tyres when on rather hard ground or rarely on road / gravel - when reduced pressure is not required?
Had once ( a couple of years ago) the chance to sit in an argo atv 6 wheel - driven by sticks like a tank.. they are equipped with special low pressure tyres just 0.3 bars / 4.35 psi

Good website here:

Tyre Size Calculator

A better easy to use tyre size calculator. Use our tyre size calculator to find tyre diameter, width, sidewall, circumference, and revolutions per mile.

tiresize.com

Tyre pressures dependent on info from car manufacturers and tyre company but for me on 265/65/18 I run 33/36 on road and air down to 15/18 off road (sometimes less/more depending circumstances and loads). front/backs respectively in psi

 

[painter]

So the 35" will have a greater outer diameter on same wheelsize.. what is the size / length of the sidewall between tread and rim of wheel then calculated
same size as tread width? It is significantly more.
To those of you who are experienced offroaders - during offroading - tyre pressure is reduced to increase traction (obvious)
However what is average normal pressure in such tyres when on rather hard ground or rarely on road / gravel - when reduced pressure is not required?
Had once ( a couple of years ago) the chance to sit in an argo atv 6 wheel - driven by sticks like a tank.. they are equipped with special low pressure tyres just 0.3 bars / 4.35 psi

Example:
BFG KO2 265/70R17 121. overall diameter (OD) 805mm, section width (SW) 280mm, sidewall (S) ~186mm

BFG KO2 315/70R17 113. OD 874mm, SW ~330mm, S ~221mm

BFG KO2 35x12.5R17 121. OD 876mm, SW ~330mm, S ~221mm

Source

All-Terrain T/A KO2 Tire | BFGoodrich Canada

The All-Terrain T/A KO2 is BFGoodrich’s toughest all-terrain tire ever. Its toughness, durability and traction in mud and snow are unmatched.

www.bfgoodrich.ca

Tire pressure comparison of minimum psi for a given load, can look here http://www.toyotires.ca/sites/default/files/application_of_load_inflation_tables_20170203.pdf

Ah yes the Argo, proudly assembled in Hamburg where they put together the supplied flat packs.

Notice the Argo has no conventional suspension (springs, shocks etc). The tires ARE the suspension. So they use very low pressure, also for flotation on soft ground.

 

[OGrid]

So the 35" will have a greater outer diameter on same wheelsize.. what is the size / length of the sidewall between tread and rim of wheel then calculated
same size as tread width? It is significantly more.
To those of you who are experienced offroaders - during offroading - tyre pressure is reduced to increase traction (obvious)
However what is average normal pressure in such tyres when on rather hard ground or rarely on road / gravel - when reduced pressure is not required?
Had once ( a couple of years ago) the chance to sit in an argo atv 6 wheel - driven by sticks like a tank.. they are equipped with special low pressure tyres just 0.3 bars / 4.35 psi

Hi klarie,

I run the manufacturers recommenced tyre pressure for all on road and dirt road driving.

The question I see though is the definition of ‘off road’ driving. In some circumstance this is personal preference. Some people I’m aware of reduce tyre pressure a bit for heavily corrugated dirt roads. I am not one of those (yes I know the theory, but at high speed I want stability).

The only time I reduce tyre pressure is for soft sand and low speed rock crawling. 18 PSI for that. Lower if required for extreme conditions, or if you get stuck. To me the risk is greatly heightened for pulling the tyre off the rim at <20 PSI. So sharp adjustments in vehicle direction is to be avoided where possible at low pressures.

Edit: I’m very interested in BushGuide‘s thoughts on tyre pressures. @Bushguide

After seeing the Grenadier in the Namibia videos I’m now very keen to checkout 35” tyre options for extended treks. @DaveB the thought of running 35” tyres on Fraser with the Grenadier is very appealing…to dance around the stuck Prados and HiLuxs.

 

[bemax]

Example:
BFG KO2 265/70R17 121. overall diameter (OD) 805mm, section width (SW) 280mm, sidewall (S) ~186mm

BFG KO2 315/70R17 113. OD 874mm, SW ~330mm, S ~221mm

BFG KO2 35x12.5R17 121. OD 876mm, SW ~330mm, S ~221mm

Source

All-Terrain T/A KO2 Tire | BFGoodrich Canada

The All-Terrain T/A KO2 is BFGoodrich’s toughest all-terrain tire ever. Its toughness, durability and traction in mud and snow are unmatched.

www.bfgoodrich.ca

Tire pressure comparison of minimum psi for a given load, can look here http://www.toyotires.ca/sites/default/files/application_of_load_inflation_tables_20170203.pdf

Ah yes the Argo, proudly assembled in Hamburg where they put together the supplied flat packs.

Notice the Argo has no conventional suspension (springs, shocks etc). The tires ARE the suspension. So they use very low pressure, also for flotation on soft ground.

The Argo might indeed not be the perfect example for cars tyre pressure. But it is a hell of a fun. @klarie I guess you drove the version fitted with blue light and siren for fire fighters, didn’t you?

 

[DaveB]

Hi klarie,

I run the manufacturers recommenced tyre pressure for all on road and dirt road driving.

The question I see though is the definition of ‘off road’ driving. In some circumstance this is personal preference. Some people I’m aware of reduce tyre pressure a bit for heavily corrugated dirt roads. I am not one of those (yes I know the theory, but at high speed I want stability).

The only time I reduce tyre pressure is for soft sand and low speed rock crawling. 18 PSI for that. Lower if required for extreme conditions, or if you get stuck. To me the risk is greatly heightened for pulling the tyre off the rim at <20 PSI. So sharp adjustments in vehicle direction is to be avoided where possible at low pressures.

Edit: I’m very interested in BushGuide‘s thoughts on tyre pressures. @Bushguide

After seeing the Grenadier in the Namibia videos I’m now very keen to checkout 35” tyre options for extended treks. @DaveB the thought of running 35” tyres on Fraser with the Grenadier is very appealing…to dance around the stuck Prados and HiLuxs.

I have seen a few reports from people in the industry who think 31-33" is the best size in Australia and 35" is too large.
Particularly for soft sand where you end up pushing a huge wall of sand in front of you.
Assuming the 35" are also a bit wider as they usually are.
I have never driven with 35" tyres so only second hand information.
I know when I drove the Grenadier in Perth on soft sand, it was on the K02's at full road pressure, and it went through easily in 4 high without the centre diff locked. ( I think??)
One bend was about 250mm deep wheel ruts in the sand and I could feel it squirming a fair bit but it never hesitated.
I think if you dropped them to 20psi, locked the diff and put it in low range it would eat Fraser.
Maybe rear diff lock if the sand was hot in summer.
It will be fun to find out.

 

[Disco Dave]

So the 35" will have a greater outer diameter on same wheelsize.. what is the size / length of the sidewall between tread and rim of wheel then calculated
same size as tread width? It is significantly more.

First of all a “wheel” is a combination of both rim and tyre. For a 265/70/R17, the distance between the rim and the outer tyre (wall height) is 265mm x 0.7 = 185.5mm. And for a 285/70/17 it will be 285 x 0.7 for 199.5mm. To get the total diameter, of the wheel, you need to multiply the wall height by 2, then add the rim size. However the rim size is in inches, so you need to do some converting - just to make it easy.

 

[klarie]

Thank you all - got really enlighted.
The Argo I sat in (wasn't allowed to drive it) belonged to some company in the Alps - the vehicle was just offloaded a trailer near Unternberg / Ruhpolding when I came along there.
- No fire / rescue service. The vehicle was greyish green. I was there for touristic and playing golf. (Modern Quads / ATV - or side by side ATV or JD Gator were uncommen and I was stunned and excited seeing one of these and I asked the guys what it was - never seen such a vehicle before) - Nowadays we 've got at least 3 dealers in close range selling quads, side by sides..

 

[painter]

Thank you all - got really enlighted.
The Argo I sat in (wasn't allowed to drive it) belonged to some company in the Alps - the vehicle was just offloaded a trailer near Unternberg / Ruhpolding when I came along there.
- No fire / rescue service. The vehicle was greyish green. I was there for touristic and playing golf. (Modern Quads / ATV - or side by side ATV or JD Gator were uncommen and I was stunned and excited seeing one of these and I asked the guys what it was - never seen such a vehicle before) - Nowadays we 've got at least 3 dealers in close range selling quads, side by sides..

You know it floats, right ?

If you are a hunter and you buy an Argo, then you won't need a dog to retrieve your bird !