Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/127212
START WINNING TODAY! 1989 YAMAHA YZ250W For experienced ride rs onl y . 9lZZLING 9UMMER ··YZ" 9AL.E ..., V ,.Q o .... u o PRICES SO LOW WE CAN 'T PR INT THEMI -DRY WEIGHT 2141bs. . -UPS IDE DOWN CARTRIDGE FORKS. -MIKUNI 38MM FLAT SLIDE CARB. -SMOOTH, FAST, TORQUEY MOTOR. l Read Cycle News Want Ads! LEATHER SUPERSTORE Complete Line For Street & Track One Piece Suits, Two Piece Suits, Boots Gloves,. Back Protectors, Knee Sliders , Toe Sliders, Rainsuits, Jackets All Colors: All Sizes Also: Complete Line of Arai Signets and Dunlop K591Rs SUZUKI OF PALM BEACH 845 N. M il itary Trail West Palm Beach, Florida 33415 (407) 683-3722 RC30 AVAILABLE FOR ORDER NOW! Come Ride With Us 30 PRODUCT EVALUATION SIMI HONDA 805-526-4122 818-702-0662 Simi Valley,CA .aiC • UPS Daily What Is Your Problem? Tell" to the editor, write him a letter. KDX·200 RIDERS BOLT ON BIG BORE POWER CAN YOU HANDLE .. ~Oc ~n L.A. Sleeve Co., Power Prod. Div. 8311 Chotte A.I., Santa Fe Springs, CA 90670 Na~onal TolI·Free Order No. 1-800-822-6005 Galif. Order Number & Tech Info. 213-94~578 Dunlop's latest sport bike tire is the Sportmax ZR, a Z-rated, low-profile radial developed from lessons learned in Grand Prix road racing . Here, the front (left) and rea r (right) are mounted on a 1989 Suzuki GSXR 11 00. Dunlop Sportrnax rad ials Dunlop recently unveiled its Sportmax ZR, a new radial tire designed especia lly for street-going sport bikes, and encompassing the lesso ns learned in Grand Prix road racing. We ha d the opportunity to sample their latest creation on a 1989 Suzuki GSXRIIOO. This is a bike tha t has seen more than a few sets of tires this year - including the stock Michelins, plus Micheli n's Hi-Sport radials - so we were able to make some comparisons. The Sportmax introduces what Dunlop calls Molec ular Engineered Polymer (MEP), a heat-resistant tread compound that gives maximum grip at all temperatures. 'T h is comes as no surprise to GP fans, as Dunlop radial slicks have consis tently proven superior during . the starts of this year's GPs, particularly in the hands of Team Lucky Strike Roberts' Wayne Rainey. In street terms , this trans lates . to a tire that works we ll when cold, wit hout needing a warming period. Since today's large displacement motorcycles can attain racer-l ike speeds of over 170 mph, the Sportmax tires employ Kevlar belts to minimize casing distortion at those velocities, as well as to promote stability and even wear. The Sportmax is Z-rated for sustained speeds of 149 mph and above, the highest rating currently available. We found the Sports max tires provided ample traction, even when cold, yet they wore like iro n . One round trip between Los Angeles and Blythe, California, . encompassed approximately 500 miles of mostly desert freeway travel, with air tempe ra tures of over 120 degrees and road temperatures far above that. We worried what effect the heat would have on the tires (paying' particularly close attention to air pressure). but experienced no problems and wear was m in imal. The rear Sportmax was especially impressive in its predictability. T he rider was consistently able to break the rear end loose without having it violently step out of line, and without the usual accompanying big eyes, increased heart rate. and gasps for breath. The most no teworthy trait of the front Sportmax was its behavior under braking. where it exhibited very little tire squirm one of the biggest complaints levied against radi als thus far - although it d id have a tendency to make the bike stand up under braki ng. On the negative side, the front Dunlop did slow steering substantially from the Michelins fitted previously, and provided marginally less grip. However, the Sportmax afforded better feedback to the rider, and in a street tire that's a trait we consider at least as desirable as racer-like traction. -In terms of feel, these are the most bias-like radials we've yet encou ntered. The Dun lop Sportmax ZR is . available in sizes to fit most current sport bikes. Suggested retai l prices range from $105.38 to $109.90 for the front tire, and $127.90 to $143.80 for the rear. •

