Outer Limits 4x4 Board

Just got another GQ for bush bashing and im now trying to figure what would be more capable. example 35"x 10.5 ext trekker or a 35"x12.5 baja type tyre.i guess the driving is a bit of mud but more rock and gravel.do the skinnies give good side wall traction/bag affect if stradling deep ruts etc.its purely for the bush so i dont care about compramise just traction.

go the 12.5's mate. there commen

12.5's

10.5 with a nice offset rim good for mud!!

go the claws

the nissans are a fat beast but to protect the body i would shove something a little wider on there

12.5s! they have a natraly bigger footprint so will give better traction, that simple! oh and they are a nicer ride also.




that and thry look tuff! hehe

Why not go the 35x11.5 extreme trekkers if you want more width

12.5s

For mud you will be hard pushed to beat the Simex (but I'd say go with the 35x11.5) however if you are on hard surfaces then you want the wider tyre! Pretty simple really, you either need both or decide which surface you will be on the most.

12.5 looks tough so all the kids like them, 10.5 cuts through mud about fifty times better.

I don't think there's even a debate about whether a skinny tyre or a fat one works better in gooey mud personally. I've seen skinny nearly bald truck tyres do better than wide chunky muddies.

Having said that I've got 33x12.5 MTRs because they look cool

As BJ said, the 12.5's are perfect because they hold the side of the car off against walls and deeps ruts. Thats one of the best things about my MTRs.

I try to stay around 12.5" widest I go would go is 13.5" personally I find wider then 13.5 is to wide so 10.5 to 13.5, dont forget that a patrol is a heavy fat assed bitch so the footprint is important, wide tyre better ride. Most important would be get the tyre to suit the terrain you intend to drive in/on.

the terrain thing is a hard thing to say.im over the mud thing due to expence so its more rock but i like the idea that like before trips when the weather turns to sh#t and it all turns to clay and mud i can still get out reasonably well.so rock and gravel are the surfaces i chase but sometimes to get to and from these there will be mud......................................am i asking to much.......thanks for all the input so far fellas.how would the JT2 go as a balance.

mate get the skinny, army looking tyres that u see on some old landcruisers. if they worked on a 1940 something willy's jeep through mud that would bog tanks, they will work on a much improved 4wd like the gq. i think u can get them in like a 16ply or something ridiculous too, makes them alot harder to stake (happens alot to my cooper st's)

A wide tyre will not give you a better ride, in fact it will actually give you a harsher ride, due to the fact you will have a wide but short foot print, which means instead of gradually climbing up and down a hole or rut in the road the tyre will simply drop into the hole or rut.

The only way you can increase the footprint of a specific tyre is to either a. increase the weight on the tyre, or b. decrease the tyre pressure.

Example: If everything is held constant and you only change the width of the tyre the following will happen:

Narrow Tyre - contact patch 25cm wide and 35cm long so 875cm square with say 500kg on each tyre so 0.57 kg per square centimeter.
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|..................|
|..................|
|..................|
|..................|
|________|

Wide Tyre - contact patch 30cm wide and 29cm (roughly) long, so still 875cm square and will still have 500kg on each tyre so still 0.57kg per square centimeter.
_____________
|............................|
|............................|
|____________|

As you can see you have no more "contact" patch and therefore "grip" to speak of.

I am not saying that one is better then the other but like everything in 4wding it's about a compromise, a narrow aired down tyre will have less rolling resistance and form less of a sand wall in front of the tyre when being used on the beach.

Note: the above comparison does not take into account tyre tread, construction, compound, or a difference in tyre pressure these and other variables make the only reliable testing method available to the average joe blow, simple seat of the pants testing in their rig. Let the debate continue!

if the tyre is the same height (ie 35") wouldn't the length of the footprint be the same? Its just the Width that changes..

there is a point where tyre width becomes a negative on flotation. Narrow tyre same dia. will have less footprint, sink easier will not work on rock! hence army vehicles have real big winches. If narrow tyres are the shit why do new truck tyre come out in 400-600mm wide? Also in driving on sand you would want a wide non-agressive tyre to float across the top But to wide n it will suffer from power issues. If you were driving on a tyre with 16 ply's it would be stiff as shit n ride like a wagon wheel, wider tyre = more tyre deformation = more shock absorbsion = better ride. try doin 100km/h across corigations at 40psi in the tyres then do it the same at 20psi then tell me the tyre has no bearing on ride. Also to avoid staking a tyre you should air down and let the tyre deform around the object, not have it rock hard and force the object through the tyre.

Potter wrote:if the tyre is the same height (ie 35") wouldn't the length of the footprint be the same? Its just the Width that changes..

yes. and the better ride is created by the fact that often the holes in the road are narrower than the wider tires and so not all the tire drops into the hole. also, any bumps hit a part of the tire carrying a smaller percentage of the total weight of the vehicle and henceforth the load is spread more evenly.

its like a needle and a book. the force on them both may be the same, but bloody hell that needle hurts more!