why does heavy vehicles have mor deep grooves?
Answers
Answer: It’s the grip of the tyre on the road and is caused by the friction between the rubber and asphalt. The rougher the two surfaces, the higher the friction and the better the traction. Rubber and asphalt have a high coefficient of friction, so a smooth rubber tyre could get you along a perfectly dry road without disaster. The problem, as those of us who have face-planted outside the Singaporean Ministry of Education in our rubber flip-flops undersvtand, is when it rains. When the roads are wet, the tyres are sitting on a layer of water and the friction between rubber and water is low (face-plantingly low).This is where tyre treads come in. The grooves (or “voids”) on tyres are there to provide a channel for the water. Allowing the water to escape from underneath the tyre keeps the rubber in contact with the asphalt, maintaining good traction and avoiding slippage. The same principle applies to driving in mud and snow: the grooves in the tread expel the snow or mud from under the tyre. Typically, the deeper the grooves, the better the traction in wet conditions.Although the deep grooves remove most of the water, a very thin layer often remains. To solve this problem, treads have lots of smaller grooves called sipes. Sipes were patented in 1923 by John F. Sipe: the story goes that he was tired of slipping on the wet slaughterhouse floor, so he cut small grooves into the rubber soles of his shoes. In tyres, the tread flexes as it makes contact with the road, causing the sipes to expand and effectively suck up the water from the road.
So if all a good tyre needs is as many grooves and sipes as possible, why do we need symmetric, asymmetric, directional, all-season, winter and cold-weather tyres, and racing slicks? Unsurprisingly, there is a little more to tread design that just carving a few lines in some rubber .
Explanation: