Thread: Skinny Tyres Vs Fat Tyres

Most skinny tyre lovers say they dig down until they find the firm stuff. Oh... hang on, thats mud... assuming there is a bottom.

Sand... skinny tyre lovers like them because they give a looooong foot print. Mind you, its as long as a wide tyres foot prints also, just with less floatation.

The last time I bought tyres for my RR classic, I bought Sime Frontier in 205/80R16. See Sime 4WD Tyre Range

They were inexpensive and seemed to work well for me.

Originally Posted by Slunnie

Most skinny tyre lovers say they dig down until they find the firm stuff. Oh... hang on, thats mud... assuming there is a bottom.

Sand... skinny tyre lovers like them because they give a looooong foot print. Mind you, its as long as a wide tyres foot prints also, just with less floatation.

show me your wide tyres that will float your 2tonne vehicle over mud

so its a bull**** argument on both sides.... if there is a bottom both will find it and the width wont be as important as the tread pattern and how much clearence you have.


like i said before i drove ALL over Fraser isl on 750/16 michie XZL mud tyres.... not a problem at all.

just remember a wider tyre has to move whats in front of it......

i just dont think for 2 tyres of equal dia/height that wide offers enough of an advantage to outway the disadvantage.

my thoughts are go for the tallest tyre that suits your needs: read- will fit and wont effect your gearing adversly. this may mean that a narrower tyre will allow it to be taller and not rub etc.....

height is more important than width....

Serg

Doing some thinking about this on the drive home from Yass today.

As far as ground pressure goes, this will be the same for both wide and narrow tyres at the same air pressure, ignoring the extent to which the belt and sidewall support the vehicle with their stiffness - and have a look how much it supports with no air in it! My guess is that the variation in sidewall and belt support is independent of the width, but varies quite a lot - and in all civilian 4x4 tyres is pretty small. (Almost all the weight on the wheel is supported by the air - and the area that must be on the ground is simply the weight divided by the air pressure, using appropriate units. Width does not enter into the formula)

When comparing a wider and narrower tyre, with the same pressure, the narrow one will flatten more. This will reduce the ground clearance a little (but not much for practical tyres and pressures), and this may account for some of the differences in performance.

Bearing this in mind, the only real advantage for wider tyres as far as ground pressure goes is to the extent that they allow lower pressures to be used - but this is more dependent on construction than size, and in any case few drivers go anywhere near the lowest acceptable pressure.

As I see it the only substantial advantage of wider tyres (and this is only considering realistic sizes) is on terrain where the surface varies laterally within the width of a tyre, so that the odds are on a better grip for the wider tyre. This would apply to loose rock as noted but also to very rough but firm surfaces where the wider tyre would be less likely to "fall into the cracks". Both are likely to be significant factors only on steep slopes.

Make what you will of my musings!
John

Originally Posted by Randylandy

having ony ever had wider tyres on my 4x4's over the years was just wondering how well the skinnyer tyres go in sand in comparison as my new series3 ute will be used mainly on the beach and looking at running 7.50 16?

750/16 will be fine, but most will tell you you'll get bogged just looking at sand..... just like they think that free wheeling hubs makes it 4wd or 2wd or that if you dont have them how do you make it 4wd

anyway the best thing you can do for your series3 with regards to sand driving or any offroad work, is to make sure the suspension is working to its potential..... see ISUZUROVER about this, he has his leaf springs dialed in and has a wealth of knowledge in this area(among many others)

having soft, suple, compliant springs/suspension will lesson the chance of bouncing and digging tyres in...

Serg

Originally Posted by uninformed

show me your wide tyres that will float your 2tonne vehicle over mud

so its a bull**** argument on both sides.... if there is a bottom both will find it and the width wont be as important as the tread pattern and how much clearence you have.


like i said before i drove ALL over Fraser isl on 750/16 michie XZL mud tyres.... not a problem at all.

just remember a wider tyre has to move whats in front of it......

i just dont think for 2 tyres of equal dia/height that wide offers enough of an advantage to outway the disadvantage.

my thoughts are go for the tallest tyre that suits your needs: read- will fit and wont effect your gearing adversly. this may mean that a narrower tyre will allow it to be taller and not rub etc.....

height is more important than width....

Serg

I agree, I think that both wides and skinnies both find the bottom of mud.

Ive driven all over Fraser on 235 4X4XPC's, 285 MTR's and 33x10.5 Simex JT2's. In my opinion, of the lot of these tyres the Simex were the best. People laughed at me when I was airing down before hitting the barge, but there wasnt much of a comment when I drove around a bogged 4WD at Ngarla. Oh well. Actually, I think that open pattern tyres give better drive on the sand as long as you dont dig. HT patterns dont dig, but they certainly dont drive as well. This said, Fraser isn't difficult sand at all. Stockton gives a better indication.

It's true, a wider tyre pushes more sand... but iti's also true that the driver of a wider tyre reverses and shovels less too. I think the best compromise is a tall wide tyre with the bodywork moved out of the way to make them fit.

4wd action did a test on this topic a little while ago with different pressures and i think the conclusion was that height of the tyre was the main winner with the longer footprint and width not that importance,but i rekon 10.5 is a good width or a 235/85/16
cheers mick

Interstingly though, John Rooth when he did his same test prefered wides over skinnies on Milo. He used to run skinny Cooper CTD's I think they were called, and then moved across to wide Mickey Thompson MTX's which he found to be better. Both are supplied by ETD.