Racing: Update: Team Cycle World

Attack Performance Yoshimura Suzuki AMA Pro American Superbike.

Racing: Update: Team Cycle World

National Superbike roadracing has shifted focus in a big way over the past two years. Technical R&D was an essential element in Superbike racing ever since its beginings in the late 1970s. Most parts of production machines required modification or outright replacement with better parts to function in racing. Intensive R&D became institutionalized, making Superbike into a factory-only sport, with the wins going to whichever team was currently willing to ante up.

Meanwhile, 30 years of evolution gave production sportbikes greater performance and durability than the pure racers of just a few years earlier. This made much of Superbike racing’s R&D unnecessary, while the marketplace naturally equalized performance among all makes. This made it both possible and desirable to formally limit R&D, opening the field to more factories and private teams. The result has been closer and more varied competition.The Team Cycle World Attack Performance Yoshimura Suzuki AMA Pro American SuperBike is getting a turn-key lease engine from Yoshimura Racing. After completion, our engine will drop into a chassis donated by American Suzuki, with assembly and race setup by Attack Performance.

I spoke with Yoshimura’s Don Sakakura, manager of the Rockstar Makita Suzuki team. When I asked him how much change has taken place, he replied, “In 2008, 80 percent of our machine came in boxes from Japan. Today, we build the whole bike here in the U.S.”

I asked him about engine modifications. “From the head gasket up, it’s pretty much free,” he said. As before, intake ports may be filled with epoxy and then CNC-ported, and valve-seat treatment is open (most teams now use the Newen seat machine, which can make smooth, flowing curves). Cams are limited to stock lift but are otherwise free. Combustion-chamber shape and compression ratio may be altered, but required use of stock pistons limits options here.

What about connecting rods and cap bolts, which are required to be stock? “We change them at 1000-1200 miles,” Sakakura replied.

Valve springs, another critical component, can be of any type. Valves must weigh no less than stock—a rule previously adopted in World Superbike to slow the rise of peak revs. Under another rule being discussed, each manufacturer will be able to homologate one type of special piston; so far, Suzuki’s stock forged pistons have worked well. Standard gearbox ratios must be used, but surface treatments (such as the REM process offered by Yosh) are permitted.

Electronics, including traction control, remain open, as such systems are very much a focus of current production-bike development. And why not just go all the way to box-stock racing? Because the aftermarket is also a legitimate and long-time supporter of the sport.

As before, engine setups change from track to track; for the top teams it’s very much “horses for courses,” changing details such as port size, cam timing and compression. Lease bikes (such as the ex-Mat Mladin Suzuki GSX-R1000 ridden by privateer Taylor Knapp) advance in technical level but for various reasons are a pace or two behind the factory.