Sumitomo Take Care of Business with the Launch of Three Medium Truck Radials

East Norriton, PA, OCTOBER 2008 – Sumitomo Tire underst&s the need for tires that go the distance in the toughest applications. As a result, the company is introducing three new medium truck radials – the ST778 long haul steer tire, the ST709 regional steer, & the ST938 long haul drive tire – all designed with technology that delivers outst&ing performance & holds the line on tire cost-per-mile.
“These tires represent the next generation of Sumitomo medium truck radials,” says Richard Purol, Vice-President, Marketing for Treadways, LLC, the exclusive marketer of Sumitomo tires. “The tread designs & performance criteria built in to these tires specifically address the needs of each application. That’s important for safety, costeffectiveness, & optimal performance. &, they are all built with S-Tech Design, a collection of the best technical features Sumitomo has to offer.”
ST 778
The ST778 is the next generation Sumitomo long haul steer tire. Designed for excellent h&ling & retreadability, the ST778 delivers exceptional miles to removal. Flat Contact Technology delivers uniform contact pressure from shoulder to shoulder, enabling this tire to resist irregular wear across the full tread surface, especially in the shoulder area. In addition, redesigned shoulder grooves work with the wide, flat tread radius to control irregular wear, thous&s of micro sipes protect the interior from punch wear, & 4/32nd” stone ejectors protect the casing from damage. With a long wearing tread compound on the outside & a cool running base rubber compound on the inside, the ST778 provides significant resistance to irregular wear.
ST709
For regional haul operators, the shorter the haul, the faster the tires wear. That means increased costs. With frequent turns, stopping & starting, & sometimes scrubbing of curbs, regional steers have to be durable across a broad range of conditions. ST709 addresses these issue with a beefy 20/32nd” tread depth applied to a wide, flat casing for 10% more rubber volume & longer life in high scuff applications. Thick curbing ribs shield the casing from sidewall damage & stone ejectors protect the casing from damage in the base of the groove.
Chevron block center ribs with lateral sipes effectively cut water film on wet roads for enhanced traction & safety.
The ST709 is suitable for high-speed regional transport, local P&D, school buses, equipment haulers, refuse trucks, & even urban dump trucks primarily operating on paved surfaces.
ST938
Created to work in harmony with the ST778 & ST709 steer radials, the ST938 long-haul drive radial delivers long life, minimized irregular wear, excellent traction, & h&ling stability.
The ST938 features a super-deep 30/32nd” tread depth applied across a wide, flat radius to dramatically improve tread life. Bold tread elements deliver an optimal combination of traction & rigidity, while the S-Tech Design casing yields outst&ing long-term performance.
Deep tread tires sometimes experience heel/toe wear. Solid shoulders with a rigid interior tread block configuration on the ST938 help control heel/toe wear. Increased base tread rubber reduces heat generation while running at high speeds in a long haul operation. Diamond-cut block edges fight irregular wear & resist cuts & snags.
Sumitomo is the premium export br& of Sumitomo Rubber Industries, Ltd., one of the largest tire manufacturers in the world. Sumitomo Tires are sold throughout North America by a network of independent distributors & dealers. Treadways, LLC is the exclusive marketer of Sumitomo Tires. Established in 1985, the company offers a wide range of consumer, commercial, agricultural, & industrial tires & tire-related products. Treadways is a subsidiary of TBC Corporation, the largest marketer of replacement tires in North America. Additional information on Sumitomo Tires can be found at www.sumitomotire.com.
S-Tech Design is a collection of the most advanced technical features Sumitomo has to offer. Named for the S-shaped sipes in the ribs of the new ST778, S-Tech Design represents much more. It is the optimal combination of specific features in each new truck tire line working together for maximum performance & durability.
S-Tech Design features include:
Flat Contact Technology
Micro sipes on the rib edges
Redesigned shoulder groove
Increased tread rubber gauge
Larger tread volume
Tread groove protectors
Curbing rib
Chevron block center rib
Super deep & wide tread
Dual layer bead apex
Diamond cut block edges
Traction & block rigidity


Flat Contact Technology
Through many years of research both in the laboratory & in the market, Sumitomo has now finalized with confidence “Flat Contact Technology”. This sophisticated technology minimizes irregular wear by controlling the contact pressure in the tire footprint to provide sufficient tread width & tread depth.
Flat Contact Technology delivers uniform contact pressure from shoulder to shoulder. The contact length of the shoulder rib in the tire footprint is almost equal to that of the center rib, meaning that the contact patch is kept square while in contact with the ground. This leads to uniform contact pressure distribution & significant resistance to irregular wear.

Sumitomo tires Search Sumitomo tires by vehicle: Search Sumitomo tires by size: All other tires