SR Street/Track Day Tire Comparison Test - Both Sides Of The Fence

Avon VP2 Sport AV59/60
The latest generation of Avon's Viper series, the brand new VP2 Sport is the first Avon to feature multi-compound construction. It will be available in three types: Sport ("for everyday performance riding," which we tested), Supersport (street/track), and Xtreme (track days). The A-VBD circumferential belt used in all the rear VP2 models features a new hybrid construction utilizing both strands of aramid fiber and steel of differing tensions wound together (only steel is used with the 190 version); as before, the cable is wound at differing spacing from center to shoulder, with the high-strength aramid providing high-speed stability while the steel's flexibility and natural spring properties provide compliance for overall grip.

Avon's Tri-Compound Extrusion system uses a medium compound in the center of the tire for mileage, with a separate soft compound on each edge for good grip at maximum lean angles. Underneath both of these is a very soft, low hysteresis compound layer to help improve the bond between the two differing compounds above and the carcass.

Interestingly, much of Holst's subjective comments and ratings on the VP2 Sport mirrored Kunitsugu's experience with the Viper Xtreme. "Quicker and more precise steering [than the others]" wrote Holst, although he did note that the compliance was a bit stiff, with low marks for grip on bumpy pavement. Traction dropped off just as dramatically as the VX, although it didn't occur until the VP2's sixth lap; "front went away big just as I made my final turn-in," wrote Holst in giving the VP2 low scores for traction predictability and grip at max lean.

The VP2 didn't have as much of a fall-in tendency at aggressive lean angles as the VX on the street, but its stiff carcass did hurt compliance and confidence on rough or bumpy pavement. Overall wear rates on both track and street were moderate.

(800) 624-7470
www.avonmotorcycle.com

AVON VP2 SPORT AV59/60

Bridgestone BT-016
Released early last year, the Bridgestone BT-016 uses the company's successful MotoGP experience to develop sport tires with multiple compounds in both front and rear tires. The front BT-016 uses two compounds, one for the center and one for both edges; the rear BT-016 goes a step further, and features three separate compounds--a hard one in the center for wear, with two successively softer compounds in the shoulder and edge on each side. The transition compound in the middle of the rear tire's shoulders is identical to the center compound of the front tire, while the edge compound is the same on both. Bridgestone's Mono-spiral circumferential steel belt is used in both front and rear tires. Tread patterns are predictably sparse, with the front featuring s-shaped grooves in the center for wet braking, while the rear's L-shaped siping is designed to influence carcass deflection and characteristics such as stability and shock absorption across the tread's profile.

Holst and Kunitsugu gave the Bridgestone high marks overall at the track, with Kunitsugu liking the BT-016's stability "under braking, but especially accelerating over bumps, doesn't squirm or weave like some others." Both riders wished for a little more steering precision, however, with Holst writing that the Bridgestone wasn't "the sharpest, most precise steering." Traction and feedback were rated very good--"but short of excellent," wrote Holst, "not quite great" added Kunitsugu--with both riders stating that grip didn't fall off until the very end of their sessions.

Interestingly, the BT-016's steering precision was rated excellent on the street, with superb compliance, and overall grip exhibited on both 600 and 1000. "A tire that will improve the performance of practically any bike you stick it on," wrote Kunitsugu. Wear rates were moderate, with a lot of wear noticeable along the edge of both front and rear tires on the street and track.

(800) 543-7522
www.motorcycle-karttires.com

Bridgestone BT-016