March 17, 2010
Still revolving and evolving
New Blizzak WS-70 tinkers with tradition
By: Bob Ulrich
The Bridgestone WS-70 will be available in July.
Twenty-two years ago, Bridgestone Corp. introduced the ground-breaking Blizzak studless winter tire to the world. Seventeen years ago, the company’s United States subsidiary introduced the Blizzak WS-15 to domestic tire dealers.
Three generations later, Bridgestone Americas Tire Operations LLC announced it will make the Blizzak WS-70 available to tire dealers in July. The company says the dedicated winter tire is superior to its predecessor, the WS-60, in ice, snow, slush and wet braking; ice and snow acceleration; snow, wet and dry handling; and wear (thanks to a deeper tread depth).
The WS-70 performs the same as the WS-60 in ice handling, and rides just as quietly. There is one trade-off: ride comfort.
“The compound is where we’re making the most of the advances in winter tire technology,” says Mark Johnson, manager of product marketing.
Technological advances
The evolution of the Blizzak often occurs at the molecular level, according to Johnson. That makes some of the features hard to see with the naked eye.
• Tube Multicell compounding is the key to Blizzak technology. Thousands of microscopic “tubes” or pores are designed to bite into icy surfaces for traction. They are larger in the WS-70 than they are in the WS-60.
(Not all members of the Blizzak family feature Multicell compounding. For example, the Blizzak LM-60 performance winter tire line does not, whereas the Blizzak DM-V1 light truck and SUV tire line does.)
• A proprietary NanoPro-Tech polymer helps prevent the rubber compound, especially the silica filler, from stiffening when the temperature drops.
• New 3D zigzag sipes in the tread blocks are molded vertically at various angles to keep the tread blocks stiff and reduce squirm.
The tire’s tread width also has been optimized, “which creates an elongated footprint” and enhances the WS-70’s snow and slush performance compared to the WS-60, says the company.
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