A Quartet of Electronically Enhanced Superbikes | MC Comparison

Class of 2011: Divine Intervention

By Aaron Frank, Photography by Joe Neric, Kevin Wing, Matt Samples

Chuckwalla Valley Raceway
They don't call it desert center for nothing
WORDS: Ari Henning
PHOTOS: Kevin Wing
All a superbike needs to impress you with its power is a long, straight stretch of road, but corners are where a bike’s true character comes through. Eager to expose the intricacies of our four testbikes’ personas, we headed to Chuckwalla Valley Raceway in Desert Center, California.

CVR opened last spring and enjoyed a successful debut season, for good reason. The course is safe, well thought-out, challenging and relatively smooth. Although it’s an easy track to learn, it’s difficult to master, thus entertaining for riders of all skill levels.

A few slow laps during your first visit will help you get acquainted with which way the track goes. And once you start stringing the corners together, Chuckwalla offers addicting flow, even left/right tire wear and a pretty intense workout. There’s no time to rest and no long straights, but the track is still plenty fast; we never clicked into fifth gear yet still saw 135 mph on the dash.

Chuckwalla’s grounds are Spartan, but proprietor (and SoCal Track Days owner) Mickey Grana is making regular improvements. Garages should be under construction by the time you read this, and a second road course is in the planning stages. Interested in experiencing the track? Check out www.chuckwallavalleyraceway.com to view a calendar.

Since Chuckwalla sees a bike laid over on its side for roughly half of each near-2-minute lap, cornering grip took precedence in selecting an appropriate tire for this year’s comparison. The footprint of Dunlop’s D211 GP-As grows the further you lean over, with the maximum occurring at an elbow-dragging 50 degrees. With that in mind, we dialed up Kevin Erion of Erion Racing (www.erionracing.com), Dunlop’s new West Coast race tire distributor.

Dunlop D211 GP-A Tires
Made in the USA for the AMA
WORDS: Ari Henning
PHOTO: Joe Neric
What’s the difference between Dunlop’s D211 GPs and GP-As? The “A” stands for America, referring to the tires’ country of origin. Although engineered in England, they’re constructed in Buffalo, New York, and are the “spec” tire for the AMA Daytona Sportbike and Supersport classes.

Like the UK-made tires, the GP-As utilize N-TEC (New Technology) carcass construction that blends nylon and Aramid belting to achieve the desired balance of straight-line stiffness and cornering compliance. The tires also incorporate the steep IRP (Intuitive Response Profile) first introduced on the Sportmax Q2s, and have a multi-compound rear and single-compound front tread.

Although day one of our test saw some wear issues due to low track temperatures and windblown sand, day two was warmer and calmer and resulted in much better tire life, in spite of our traction control-induced ham-fisted riding. The GP-As’ aggressive profile improved the responsiveness of all our testbikes, helping them turn-in faster and feel more planted at full lean, yet didn’t adversely affect straight-line stability or cause undue front-end nervousness as some steep-profile tires do.

Thanks to the bikes’ electronic rider aids we were able to safely see just how well these tires stuck, and it was amazing how much power the medium-compound rears could handle. The hard-compound fronts didn’t offer a lot of feedback, but seldom slid and lasted all day, both days.

The D211 GP-As are available in several compounds, but seeing as how they’re made specifically for AMA Pro Racing they’re only available in 190/55-17 rears suitable for high-powered sportbikes. Fronts retail for $155 and rears for $220, right in line with other DOT race tires and relatively affordable considering their pedigree.

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