Admittedly, it's probably not first thing you notice when looking at a tire but those little cuts you see running across the tread are called sipes. These sipes play a big part in keeping you safe on the road. In fact, a 1978 report by the US Safety Council found that siping improved stopping distances by an impressive 22%. But how do sipes, which were first developed by slaughterhouse worker John Sipe in the early 1900’s, work? Well, there’s two ways that sipes contribute to keeping you safe on the road, the first is by expanding as it contacts the road and absorbing any rain or slush. This water absorption maximizes the amount of tire tread that contacts the road which, in turn, increases vehicle stability. A second way that sipes increase traction is by increasing the number of edges on a tire that grip onto the road surface.
Now not all sipes are identical or have the same function. The first tire sipes were simply thin, horizontal cuts that ran across the tread. While these early sipes improved traction the tread block was prone to shifting which increased road noise and contributed to uneven tread wear. To combat this Toyo developed the mult-wave sipe, which, as the name suggests, consists of a wave like siping pattern through the full tread depth that interlocks providing in a more stable tread block with reduced road noise and uneven wear. Toyo then took the next step in siping and developed the spider sipe. As the name suggests this sipe resembles a spider web with horizontal and vertical patterns to provide maximum traction when accelerating, cornering, or braking.
The phrase necessity is the mother of all inventions has no better example than the sipe. From the sipes humble beginnings in a slaughterhouse nearly one hundred years ago to becoming an integral part of a tire and helping to keep our roads and highways safe. So perhaps the next time you look at a tire you’ll have a new found respect for those small cuts on a tire.