4.3L XJ

I raised the topic of siping on another thread and decided to start a new one for this discussion. Mud treads typically do not get good traction in wet or snowy conditions because of the blocks and amount of rubber touching the pavement and the lack of sipes. Sipes are cuts made in the tread to give additional traction on snow and ice, as well as channel some water away from the surface of the rubber. When I get mud tires, I have them siped. In other words, I have the tread cut. This is what it looks like.



As you can see, where the cuts are made there is a little void created that works the same as the ones on the all season tires. Here is a pic of the ultimate snow tire.



That is a lot of sipes.

Siping has also been used in the rock crawling arena before the advent of real sticky rubber to increase traction on rocks also.

fantic238

Very nice. Obviously the wear is faster. But who cares. In my research on the web for the ultimate traction bolt on system i came up with this:
http://www.best-grip.com/eng/default.asp
That's what i want for christmas hehehe...

XJ Stryker

You pay a lot for M/T's and then you want to screw them up and make the wear faster. Not very smart. Pick you up some old Jeep Steelie rims and then slap some tires on those then just Drive on those when you don't need your terrains. I think you would save more money in the long run.

4.3L XJ

Hey guys, the opposite is true. Siping has been used by the trucking industry since the 70s to increase tire milage. By making the rubber blocks smaller, the tire runs cooler and by extension longer. The increase in traction is a side benefit.

fantic238

4.3L XJ unfortunately this is a misinformation. Winter tires (thermal tires) have those cuts for two reasons. The first one is to produce heat from the rubbing of the little blocks while rolling, to keep the tire at operating grip temperature on cold surfaces. The other reason is for grabbing a little amount of snow in between so that the traction on snowy surfaces is better. This rubbing, together with a higher amount of silicon in the rubber mixes, will produce an excessive heat on dry pavement and wear the tire fastly, just like with racing tires. Now if you do these cuts on a "normal" tire you will not only have higher temp, but the edges will lose gradually little parts of rubber because of the extended surface exposed to the pavement. The only benefit is more traction. In the trucking history there has been a boom of this siping only around the seventies, because of the tough mixes they used at that time, to increase traction on wet surfaces. Today it is not used anymore thanks to a better engineering of the tires mixes that have different viscosity on the outside and around the thread. If you look at a modern truck tire you will notice that they are almost slick with only some vertical groove for water draining.

4.3L XJ

Those tires in the pic have 30,000 miles on them. I'll be sure to tell them to wear a little faster from now on. I'll have to tell the entire U.S. trucking industry also.

EndlessMtnFab

Siped tires run cooler. Not hotter. So they *should* last longer. At worst .. they do nothing to help or hurt tread life.


The purpose of the sipe is to create additional biting edges ... not to premelt the ice underneath for you. Snow tires are designed to pack snow "unto" itself .. much like packing a snow ball. Snow sticks to itself better. It becomes a balance betwen packing snow and releasing enough so fresh snow can pack in (thereby creating traction).


Whoever taught you about the heat thing should be strung by the nutz.



FWIW ... I sipe all my tires (have a hand machine) and I offer it as a service to my customers.


4.3 ..... might want to tell your tires to heat up the road more, that way you don't have to waste electricity turning on your heater too.



http://en.wikipedia.org/wiki/Siping_(rubber)



There is some reading for everyone.



FWIW .... my A/T tires tend to get at least 45K on them (or more) despite the siping.



Joe

EndlessMtnFab

My only personal thought ... is not to sipe the outside blocks. Particularly for an offroad tire.


I feel it could lead to chunking because of the additional forces the outside lugs see. However, that's only an opinion.


Siping the inside blocks for the rocks is



Joe

4.3L XJ

A quote from Wikipedia

A 1978 study by the US National Safety Council found siping improved stopping distances by 22 percent, breakaway traction by 65 percent, and rolling traction by 28 percent on glare ice[3].

fantic238

You don't even read what you link:
"Microsiping can dramatically improve tire traction in rain and snow. However, microsiped tires may also have increased road noise and tire wear when operated on dry surfaces"

And from here:
http://en.wikipedia.org/wiki/Snow_tire

"Mud and Snow, (or M+S, or M&S), is a classification for specific winter tires designed to provide improved performance under low temperature conditions, compared to all-season tires. The tread compound is usually softer than that used in tires for summer conditions, thus providing better grip on ice and snow, but wears more quickly at higher temperatures. Tires may have well above average numbers of sipes in the tread pattern to grip the ice."

4.3L XJ

Let's finish that quote "Some companies such as Les Schwab however claim that microsiped tires reduce tire friction heat and tire wear and extended the life of the tire. [4]"

4.3L XJ

First of all, I do admit that what we call a dedicated snow tire has softer ruber and will wear faster than normal. That tire I posted in the first is a Michelin Alpine. Fantastic snow and ice tire, but does not wear nearly as well as the rest of the Michelin line.

The mud tires in this country have various rubber compounds in them and cannot be generalized. For instance there is the BFGs pictured above with a very firm compound. At the other end is Interco tires with a very soft compound that resists chipping, but doesn't get good traction on any surface. The ones I siped, did however seem to wear a little better than normal, which is generally very poor for that brand. Additionally, even though reported to very poorly in snow on highways, they did perform adequately for my son who makes numerous trips over the Sierras on a weekly basis.

It is a fact however that the rock crawling community began siping tires to increase traction before the BFG Krawler and Interco Irok with competition compounds were introduced. With these tires, there is no siping done due to the softness of the rubber. It is not firm enough to handle it.

I originally posted that siping would increase traction. Regardless of the temperature issue, the articles cited did confirm an increase in traction. That should stand. However, as stated not all mud tires are created equal, so the temperature issue may remain undecided. I however, will continue to sipe all my dedicated off road tires, unless of course I spring for some Krawlers or Iroks.

fantic238

Haha,
That sounds like: "Some companies such as Philip Morris however claim that smoking cigarettes does not cause lung cancer"
Come on guys, wipe the grime off your eyes, companies would say what ever they want to sell their products.
Words such as *should* and *claim* have no scientific relevance.

Even if... do you have Les Shwab tyres? No.

I am sick of trying to explain physical phenomena by simple words, but on the other hand i'm sure you would get lost at the second row of mathematical expressions defining revolving friction.

fantic238

The topic i am discussing is "wear".
Regarding "traction" i stated that in my first reply:
Never discussed the gripping performances.

Mike1998XJ

This was on Wiki-pedia also... Someone said sipes create heat... This seems to disprove that.
Mike

Sipe Tread lugs often feature small narrow voids, or sipes, that improve the flexibility of the lug to deform as it traverses the footprint area. This reduces shear stress in the lug and reduces heat build up