Tyre tread and ice.

[Gareth56]

Clearly the tread on tyres are very helpful when driving in wet weather but does it matter if a car tyres have any tread if you are driving on ice? In other words does a tyre's tread decrease the danger from skidding or decrease your stopping distance when driving on ice?

[iNow]

Having better tread on one's tire (tyre) increases the connection to the surface of the road while providing a channel for water to free itself and escape the contact region. There is more "contact patch." The reason this is helpful is because of the friction between the tire (tyre) and the road is not compromised by a middle layer of water between the tire (tyre) and the road. On ice, friction is substantially reduced, so having more surface area touching the ice is of little help, and the treads don't allow the ice to "escape."

 

Now, if you put spikes on your tires (tyres) which dug into the ice for traction, that definitely would help... but it would take more than just having good tread to minimize danger from skidding.

 

On ice, there would be a slight advantage of having treaded tires (tyres) versus slick tires (tyres)... due to the irregularities in tire (tyre) surface which would help provide some assistance by "snagging" foreign objects like rocks or sand, or even jagged parts of the ice itself... but the advantage would be very slight indeed, and skidding on ice would likely still occur regardless of tread versus no tread.

[John Cuthber]

I know you can get special tyres for snow and ice. I can't say if they work or not because I have't tried them. I also know that the local council busses use snow tyres in Winter. I presume the council looked at the costs and the savings from reduced accidents or lower insurance payments.

[iNow]

I know you can get special tyres for snow and ice. I can't say if they work or not because I have't tried them. I also know that the local council busses use snow tyres in Winter. I presume the council looked at the costs and the savings from reduced accidents or lower insurance payments.

 

Winter tires are actually more for "snow" than for "ice." When I lived in New York, we all called them "snow tires." "Ice tires" sounds silly, unless maybe you're driving a Zamboni machine.

 

More on how these tires work here:

 

http://auto.howstuffworks.com/tire3.htm

 

 

And for one retailers FAQs on winter tires, here:

 

http://www.tirerack.com/winter/tech/techpage.jsp?techid=120

[Rocket Man]

you don't get tyres for ice, you get chains on your tyres for ice. dead slow max speed.

[John Cuthber]

Please inform the couple of thousand or so people with references to "ice tyres" on the web.

[Rocket Man]

my appologies

however, chains are quite a bit cheaper, easier to put on and give better performance up steep slopes.

[MrMongoose]

Tyres with a flat featureless face have more grip on ice than those with "grip". The problem is that it's impossible to drive over ice without melting it and then youre driving on water anyway.

[iNow]

Tyres with a flat featureless face have more grip on ice than those with "grip".

How's that? I'm open to the possibility that I was wrong above, but it's going to take some further explanation to convince me of that. What is it about "flat featureless" tires (tyres) that give them more grip on ice those with tread as you've asserted above?

[MrMongoose]

The same reasoning that gives tyres (tires) without tread more grip on dry roads- e.g. slicks used for F1 racing on dry days. Greater surface area means higher coefficient of friction.

 

As you stated above, the water on the road is what causes the tyres to slide (hydrodynamic lubrication), and having slots in the tyre allows water to escape so that the tyres can grip with the ice itself. Even where there is no water by virtue of surface melting due to solar radiation, the heat caused by the friction on the tyres can melt the ice and provide a thin layer of water.

 

So yes you're right that for all practical applications a tread is better for driving on ice. All I'm getting at is that the problem with driving on ice is that you're actually driving on water covered with ice and theoretically if you were to drive on pure ice with slicks you would have more grip.. I don't even know if its possible to have pure ice at the tyre/ice interface though.

 

Basically I'm being fussy. Not going to design any snowmobiles with slicks