Narrow vs Wide

[chiko]

Hey all, i just thought i would bring up the debate about Narrow vs Wide tyres. What are everyone's opinions!

[nismine01]

Remember the OLD cars that travelled around Aus, they had about 3" X 20" tyres and went almost everywhere!

So for my money that is the way I would go.

The larger the dia of the wheel/tyre the less angle it hits the road at so it rolls over things better, won't dig into the sand as much.

Cheers

Mike:cool:

[Aaron IIA]

I run wide tyres on my Land Rover. 7.50 x 16.
Aaron

[sjane]

In the mud or on sand, would you rather be in a road roller, or tracked excavator or tank? Both have 2 long thin contact patches but one is across the vehicle and the other along. That's the extreme but for me illustrates the concept. Width adds resistance for its increase in contact patch where as length doesn't. I'd rather have a tyre that flattens out length wise when aired down.

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[superquag]

From the discussions I've had with people who know lots more than me, the drift seems to be toward skinnier/higher profile for general road and sandy off-road performance. Thin but long is better in sand than fat and wide...

The rationale given centres around a higher-profile (80% upwards) which grows proportionately more length when deflated, than low-profile/wider.

As has been mentioned 'Length' is more useful in sand that steam-roller width.

I'm currently running the traditional 235/70 R16 on my Classic. Identical rolling radius to the 'Recommended' 205 R - 16 which are 82%.
These tyres are past their use-by date, and I'm sorely tempted to go for 225/75 R16 simply 'cos I've got 3 useable ones on rims as spares, and this would standard-ise for both work and playtime.:p

[kelvo]

Narrow or wide are meaningless. At what size does a tyre go from being narrow to wide?

[superquag]

Progressive in sizes, from recommended width (narrow) to larger (normal) and then to road-roller.

With a Classic, 205 wide and 82% aspect ratio was standard fitment. I'd call this Skinny.
Next step is 235/245 and 70% aspect ratio. Normal.

WIDE would be 255 and up, and either 70% or lower aspect ratio.

Maybe not accurate, but it's a starting point for The Argument. :eek:

[olbod]

From the discussions I've had with people who know lots more than me, the drift seems to be toward skinnier/higher profile for general road and sandy off-road performance. Thin but long is better in sand than fat and wide...

The rationale given centres around a higher-profile (80% upwards) which grows proportionately more length when deflated, than low-profile/wider.

As has been mentioned 'Length' is more useful in sand that steam-roller width.

I'm currently running the traditional 235/70 R16 on my Classic. Identical rolling radius to the 'Recommended' 205 R - 16 which are 82%.
These tyres are past their use-by date, and I'm sorely tempted to go for 225/75 R16 simply 'cos I've got 3 useable ones on rims as spares, and this would standard-ise for both work and playtime.:p

I have had 225/75/R16 on Me Disco for many years and from that experience I would never go to a different size.

[Tank]

Remember the OLD cars that travelled around Aus, they had about 3" X 20" tyres and went almost everywhere!

So for my money that is the way I would go.

The larger the dia of the wheel/tyre the less angle it hits the road at so it rolls over things better, won't dig into the sand as much.

Cheers

Mike:cool:
Try riding a pushbike in soft sand, then hop on a quad bike, nuff' said, Regards Frank.

[Jeff]

If you do a search, this subject has been done to death, with opinions by experts and the opinionated alike.

It would depend on your usage and how much you want to spend, also what is big on a D1 or RRC is standard on a Defender.

I have two sets of wheels, some 33/12.5-15 KM2s for playing and 235/85-16 ATRs for commuting and long trips. Both have their good and bad points.

Jeff

:rocket:

[debruiser]

Try riding a pushbike in soft sand, then hop on a quad bike, nuff' said, Regards Frank.

Although a valid point and probably a good argument, I think it's a little more complex than that... for a start the quad bike will stay balanced where the push bike is extremely difficult to stay balanced in very soft sand. I have personally ridden 20+kms on a bike to go fishing at the end of a beach... wasn't that hard at all just as long as you stay clear of the super soft stuff.

[sjane]

You're also comparing 1 wheel drive through bugger all contact patch to 4 wheel drive.

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[Tank]

You're also comparing 1 wheel drive through bugger all contact patch to 4 wheel drive.

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Try this then, get a 4 wheel billy cart with 1" wide wheels and try pushing it through soft sand, then get same billy cart and fit it with fat tyres and wheels off a Quad bike, you are flogging a dead horse, Regards Frank.

[Alex 110]

Try this then, get a 4 wheel billy cart with 1" wide wheels and try pushing it through soft sand, then get same billy cart and fit it with fat tyres and wheels off a Quad bike, you are flogging a dead horse, Regards Frank.

Get the 1 inch wide tyres with a high enough sidewall that you can run them at the same pressure as the quad tyres (usually ~5psi) without the rims hitting the ground & its a whole different ballgame

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[JDNSW]

Try this then, get a 4 wheel billy cart with 1" wide wheels and try pushing it through soft sand, then get same billy cart and fit it with fat tyres and wheels off a Quad bike, you are flogging a dead horse, Regards Frank.

The comparison is a little unrealistic - if a 7.50 tyre is equivalent to a bike tyre, then the quad bike equivalent is a tyre about 36" wide - and the same diameter. I don't know about you, but I don't remember seeing this sort of tyre width on any Landrover!

The narrow vs wide on Landrovers is realistically a difference in width of maybe as much as 50%, where the bicycle/quad bike comparison is a ten times greater difference. This means the bicycle/quad bike comparison is meaningless in this discussion.

John

[sjane]

Try this then, get a 4 wheel billy cart with 1" wide wheels and try pushing it through soft sand, then get same billy cart and fit it with fat tyres and wheels off a Quad bike, you are flogging a dead horse, Regards Frank.

Sorry I thought we were comparing narrow vs wide with equivalent contact patch. If you fit a wider tyre it will not have to stretch out as much length wise to carry the same load as a skinny tall tyre. Your comments are correct but you're really just changing the contact area, where as I thought we were comparing the contact patch shape.

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[DiscoMick]

So why, up in Norway and Iceland where there is lots of snow, do they go for really wide tyres to float over the soft stuff? Wouldn't the same theory apply on sand?

[Lotz-A-Landies]

Remember the OLD cars that travelled around Aus, they had about 3" X 20" tyres and went almost everywhere!

So for my money that is the way I would go.

The larger the dia of the wheel/tyre the less angle it hits the road at so it rolls over things better, won't dig into the sand as much.

Cheers

Mike:cool:Yes but a 3" x 20" is only equivalent of a 5.00 x 16 in diameter.

The reason the really old cars went "everywhere" is that they were very light.

We've all seen the original Suzuki LJ10 and LJ20s they could also go anywhere, but could only carry three sandwiches and a bottle of water but if they got stuck, 4 people could lift them up and carry them out of trouble.

The question about tyre selection depends very much on terrain. Wide large diameter wheels tyres depend upon floatation as in sand, narrow wheels/tyres depend upon not breaking the surface or cutting through it to get traction.

Tracked vehicles are essentally wheels with about a 20 foot diameter or more, but even they get bogged. We saw that in WWII the German Panzers had narrow track pad widths and bogged down in the mud and snow of Russia, where the Russian T34 had wide track pad widths and ran rings around the German machines in the same terrain.

After the War the US military sudied wheels and tyres and moved from dual narrow tyres like 7.50 20 into 12.00 20 and larger that we saw on the later military trucks. We see the same in the Inter Mk3 and the Bedford RL which replaced the dual wheeled CMP (Blitz) trucks

[TeamFA]

So why, up in Norway and Iceland where there is lots of snow, do they go for really wide tyres to float over the soft stuff? Wouldn't the same theory apply on sand?

Yes... I admit I'm also confused as to why a narrower tyre would be preferred to a wide one on sand. As long as you get the same length of contact patch after reducing air pressure, the total surface area would be greater, therefore the pressure-per-unit-surface area less, which would help to prevent sinking into the sand.

Or so my reasoning goes. I know that with our 35" 12.5 mud-terrain tyres, once they're let down to an appropriate pressure, no sand has ever even looked like stopping us.

I have heard of the theory of a greater amount of sand being pushed ahead of the tyre as a "wave" on a wider tyre, but I can't see the physics of this outweighing the benefits of a greater contact patch.

[Redback]

Remember the OLD cars that travelled around Aus, they had about 3" X 20" tyres and went almost everywhere!

So for my money that is the way I would go.

The larger the dia of the wheel/tyre the less angle it hits the road at so it rolls over things better, won't dig into the sand as much.

Cheers

Mike:cool:

So going on your theory, you're better off on 3" x 20" than 255mm or 10" x 20" on a RRS in the sand:eek:

Baz.

[PAT303]

So why, up in Norway and Iceland where there is lots of snow, do they go for really wide tyres to float over the soft stuff? Wouldn't the same theory apply on sand?

Ground pressure. Pat

[rangietragic]

A high profile tyre giving x amount of contact area beats a low profile tyre giving x amount of contact area on sand,on a race track the opposite is true.Wider tyres are better on sand,as long as they have a corresponding longer footprint;)

[chuck]

I had 265 75 16's on my D2 and they were great.

Some of the other benefits of a wider tyre are road holding and comfort.

The other thing to factor in is technology.

My D4 with 255 55 19's is more effective in the sand than my old D3 with 265 70 17's.

[DiscoMick]

So, it it better to have a narrow tall tyre giving a longer contact patch or a wider not so tall tyre giving a wider contact patch. Im confused.

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[350RRC]

From memory 4WD Monthly or 4WD Action or whatever it is called did an article about 10 years ago on this and found that aired down skinnier tyres had a slightly larger contact patch than fat tyres.

If you think about this in a sand context the longer contact patch of skinnier tyres should have more grip because the end part of contact is gripping more compacted sand. (The 'plough' effect of wider tyres might also be a disadvantage to forward progress)

My POS has always had 31 x 10.5's on it and only been badly bogged twice....... both times in really soft mud. Never had to air down in sand, even as soft as metre deep talcum powder.

On road is another consideration......... width in the rain equates to aquaplaning even with new tyres of good design.

I am going to a narrower tyre soon, but not a 205, that might have been OK in 1970 but not now.

cheers, DL

[Aaron IIA]

After the War the US military sudied wheels and tyres and moved from dual narrow tyres like 7.50 20 into 12.00 20 and larger that we saw on the later military trucks. We see the same in the Inter Mk3 and the Bedford RL which replaced the dual wheeled CMP (Blitz) trucks

Every CMP that I have known has had 9.00x13, 9.00x16 or 10.50x20 tyres, all as singles. 10.50x20 are generally now replaced with 12.00x20 as these are more readily available. Some tippers may have had duals.
Aaron

[ozscott]

Think of rolling a push bike rim through sand....now think of a log with a long wedge of sand to overcome on each roll...narrow tall profile wins every time. The approach angle is much better also. I find my 245/75/16 tyres to be the best for sand, towing in soft sand. Even stopping in a cutting and starting off again towing over a tonn is not a problem when they are aired down.

Cheers

[Ancient Mariner]

Think of rolling a push bike rim through sand....now think of a log with a long wedge of sand to overcome on each roll...narrow tall profile wins every time. The approach angle is much better also. I find my 245/75/16 tyres to be the best for sand, towing in soft sand. Even stopping in a cutting and starting off again towing over a tonn is not a problem when they are aired down.

Cheers
Try it with the log weighing the same as the bike rim

[ramblingboy42]

I'm sure some brands just work better than others.

I had a set of Khumo muddies at 245/75x16 which rode at lower pressures so superior to the 697's at 245/70x16 that I currently have.

the khumo's tended to dig into sand , the 697's throw stones and slide more in gravelly roads.

I loved the khumo's though noisy on bitumen I think I'll refit them next.

I think the diff between 245/70 & 245/75 is about 25mm in diameter but the tyres perform quite differently in favour of the muddies.

[Lotz-A-Landies]

Every CMP that I have known has had 9.00x13, 9.00x16 or 10.50x20 tyres, all as singles. 10.50x20 are generally now replaced with 12.00x20 as these are more readily available. Some tippers may have had duals.
AaronSorry. :(

I must be mistaken, I was sure I had seen duals on many Blitz. The Yanks most definately had duals on the Deuce and a half and the studebakers.

https://www.aulro.com/afvb/images/imported/2014/09/798.jpg

[UncleHo]

A lot but not all,CMP pattern trucks with dual rear wheels were originally tippers,and also a lot were converted to Bedford rear diffs,and front diff centres which gave a better road speed,as CMP's top speed is about 40/45 miles an hour,remembering that WW11 convoy speed was 20MPH or that of the slowest vehicle in the convoy.

[Aaron IIA]

https://www.aulro.com/afvb/images/imported/2014/09/798.jpg

That is a photograph of a CMP modified to a firetruck, not an orignal CMP.
From the MB-C1 maintenance manual: C8A 9.25x16, C15 9.00x16, C15A 9.00x16, C30 10.50x16, C60S 10.50x20, C60L 10.50x20, C-GT 10.50x20.
From the MB-F1 maintenance manual: F-15 9.00x16, F15A 9.00x16, F30 10.50x16, F60 10.50x20, F60H 10.50x20, F-GT 10.50x20. None of these tyres would be for duals.
Aaron

[ramblingboy42]

off topic, but do we have a bit of blitz knowledge on this forum?

I'm toying with the idea of bringing a ford , which is quite presentable condition , in from central south australia.

just have to find out the trucking costs.....or......seriously.....it's going to cut up and dumped as scrap metal.