get a grip

[lambert]

discounting tread block flex and composition, if one were to go wider with ones tyres and also for a more open tread pattern does it follow that one will have a broadly similar amount of on road grip available as a narrower closer tread pattern or is it not that simple?

off road things will be improved, but will one suffer from magnetic ditches on the way to play?

[L90OOK]

I wish it was that simple...
By going to a wider tyre you are in fact reducing the pressure on the road surface...therefore it is easier to lock up, wheel spin & slide with wider tyres.
Going for a more aggresive tread pattern reduces the amount of rubber in contact with the road, increases the road noise & grip is usually reduced on road surfaces.

Having said all that I run 265/75x16 BFG Mud Terrains (30mm wider than the recommended 235/85x16 size) & they are excellent on my Defenders.  The mileage I get from them is excellent & on/off road performance is superb.

Also by going wider & more aggresive you will reduce your MPG!

Don't forget to tell your insurance company of any changes to tyre sizes!! :roll:

[Guardian.]

ALL OURS JUST ABOUT HAVE 35 12.5 15 AND THERE ALRIGHT, HOWEVER WHEN ITS RAINING YOU HAVE TO BE A BIT CAREFULL AS YOU SOON LOCK UP, AS  THE WEIGHT IS SPREADOVER A GREATER WIDTH, IN THEORY MAKING YOU LIGHTER, SO YOU CANNOT STOP!
ALL GOOD FUN THOUGH.

[lambert]

think for standard they should be 205/85/15's but currently they are 235/75/15's however i'm looking to go to iether 31/10.5/15's or 265/75/16's depending on secondhand wheel availability.

[SWEETY]

Mines running standard size 235/75R15's I know you can fit 30/9.5/15's but you often have to take off the front mud flaps for clearance. 31's etc you have to start modding the arches, bumper & bumper mounts etc

[lambert]

this is why god invented the sledge hammer and angle grinder :twisted:

[clbarclay]

THE WEIGHT IS SPREADOVER A GREATER WIDTH, IN THEORY MAKING YOU LIGHTER, SO YOU CANNOT STOP!

Errm confusing issues, if it made you lighter weight them it would also reduce momentum which improve breaking.

[lambert]

i see the point about reducing ground pressure.

but would not that only apply if the tread pattern stayed the same (same rubber to air ratio per unit squared)?

if you go with a wider tyre but with an enlarged tread pattern (more air less rubber per unit square) would the net effect not be to retain the same or broadly simmilar ground pressure on a hard road surface?

not talking about off road ground pressure as i know it will be and i want it to be reduced so as not to overly damage the grass.

[clbarclay]

One notable trouble with the more extreme off road tyres on the road is the height of the tread blocks. For on raod performance in the dry these should be as low as possible.


For off road situations (on soil/mud/sand etc.) pressure is not the most important part of traction, there are nominal limits depending on the exact terrain and what your trying to achive, but for example 500hp tractors can efficiently transmit all the power to the ground through tracks with a ground pressure of just 5 psi.

[Range Rover Blues]

Simple Physics would tell you that it doesn't matter how much rubber is in contact with the floor, it's simply a matter of the weight and the coefficient of friction.

Ever seen a F1 car, why do you think the tyres are so wide? The more rubber you have on the floor the mare grip you get, it's a chemical attraction between the rubber and the tarmac refered to as 'stiction'

The ocasions when a narrow tyre help are to dig through snow/mud/slush etc to the grippy surface underneath, so not a factor of it's thinnes directly but the lack of floating on boggy/snowy surfaces.

You need to choose tyres to suite what you do.  As your car is probably not as heavy as mine I'd think 235 should be more than sufficient most of the time.

For sandy surfaces go as wide as you can, for muddy tracks go thinnner, same with snow.

One diassadvantage of wider tyres is that they ride up at the sides if you drive obstacles so they need to be flexible.  And yes they will drink more fuel.

[Terranosaurus]

Simple Physics would tell you that it doesn't matter how much rubber is in contact with the floor, it's simply a matter of the weight and the coefficient of friction.

Ever seen a F1 car, why do you think the tyres are so wide? The more rubber you have on the floor the mare grip you get, it's a chemical attraction between the rubber and the tarmac refered to as 'stiction'

Nicely put, could decide how to word it so didn't reply but you've done it nicely.