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

There's no doubt that the sportbike tire market is not only constantly changing, but becoming more specialized as well. Long-gone are the days when you only had to choose between two types of rubber: street and racetrack. Now, most manufacturers offer several types of tires for sportbike riders that cover specific uses. You have "regular" street sport tires meant for hard street use, with a track day possibly thrown in. You have sport-touring tires that are designed to provide long life and smooth ride in addition to good grip and handling. And then you have the all-out, very specialized performance of the DOT race tires.

Several years ago, however, one particular market segment seemed to be gaining speed. Tire manufacturers sensed a growing desire among sportbike riders for a tire that could handle both aggressive street duty and numerous track day forays. The tire couldn't be as specialized as a full-on DOT race tire; it had to have decent warm-up characteristics, in addition to good grip and handling manners that were neutral enough for street use while offering the quick steering necessary for track duty.

At one time nearly all the manufacturers had a specific tire for this market. While some manufacturers used a street tire tread and carcass with perhaps a different construction, profile, and compound, others basically offered what appeared to be older model DOT race tires in a harder compound. Since that time, however, a few manufacturers have decided that the market wasn't big enough to warrant making a special tire, and now feel that their regular sport tire can handle combination street/track duty with equal aplomb.

Making The Call
We contacted eight manufacturers and asked them to send us the particular model of tire in their lineup that was intended for a combination of both aggressive street and frequent track day use. As with past tire comparisons, we used a 600 and literbike to not only accumulate twice the data, but also test the two most popular rear tire sizes (180/55-17 and 190/50-17). Our testbeds for this comparison would be the Suzuki GSX-R600 and Kawasaki ZX-10R. Six companies responded, with Avon sending different sets of tires for the 600 and 1000.

As per our usual test regimen, each tire was weighed, and its sidewall and tread construction noted. Once mounted on the correct size rim, the circumference, sidewall height, section height, and width were all measured; this data is included in the chart on page 69. We then sent our two usual test pilots--El Jefe (Editor-in-chief Kunitsugu) and the Geek (senior editor Trevitt) on our 180-mile test loop. This loop covers not only some freeway and city riding for real-world impressions, but encompasses the gamut of twisty road work in the canyons, from ultra-fast and smooth corners to tight, gnarly paved goat trails. The two also brought along the tools necessary to make suspension or reasonable geometry adjustments during the loop.

With the Geek being sidelined due to an accident during the latter part of street testing, resident guest tester Lance Holst was called up to replace him during the track portion of the comparison on the 600. Holst's qualifications are numerous and varied, including a five-year stint here at SR, numerous amateur club racing championships, and several periods as lead instructor at some of the top riding schools in the country (Jason Pridmore STAR school, Kevin Schwantz Suzuki Riding School, etc.); in using him for various comparison tests, we've found his evaluation skills to be top-notch, so he was a natural fit.

For the track portion of the test, we returned to Buttonwillow Raceway Park's Race #23 Sweeper circuit configuration, a nice combination of fast and slow sections with plenty of bumps to test the tires' compliance, traction, and stability. As we've done in past comparisons, we concealed which tire each rider was on so that any preconceived notions on performance wouldn't affect aspects such as confidence and predictability. Conditions were near perfect, with ambient temperatures in the 70s and no wind.

At the completion of both street test loops and track sessions with each tire, riders filled in a questionnaire that rated the tire based on its performance over the course of each session. The ratings include 31 parameters in four different categories: general, braking, traction and steering. General characteristics include warm-up time, break-in, feedback, predictability, compliance, stability and confidence (among others). Braking characteristics include feedback, predictability, and midcorner behavior. Traction on smooth and bumpy pavement, at maximum lean, and in slow and fast corners was rated. Steering categories included effort, neutrality, precision and linearity.