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/127863
PRODUCT EVALUATION Dunlop Sportmax D207 (Left) Dunlop Invited the world motorcycling press 10 Phoen ix Inte rnational Raceway tor a day of shredding its new 0207 Sportmax on a variety of sportblkes. The tread pattern Is said to mimic wear patterns of slick race tires and thus lengthen the life of the tire. (Below) Performance of the 0207s on the GSXR750 was good , sliding predicta bly and ollerlng good feedb ack. (Bottom) Honda', heavy and high-powered CBRl l 00XXtaxed the rear D207 the most, sh owing classic blg-bike wear patterns after some hard laps. By Colin Frase r Photo Kinney Jones PHOENlX, AZ, ocr.9-JI he wo rld motorcycl e press jetted into Phoenix for the launch of Dunlop's moch-a nticipated D207 spor tbike ru bber, ri ding a huge variety of machines over th ree days at Phoenix International's oval and infield road course. The importance of this new Dunlop tire Iine to the manufacturing giant's motorcycle lineup and marketi ng image was obvious: Almost 100 staffers and m emb er s of th e med ia we re , 0\ N .... Q) .g ..... U o 30 involved in the week-long u ndertaking . Stock street motorcycles on hand for tire testing included Honda's CBR600F3, . VFR750 and CBRII OOXX Bla ckbird ; Suzuki's GSXR600 and GSXR750 (no nfuel-in jected ); Kawasaki's ZX~R; ZX-7R and ZX-9R; Yamaha's YZF600, YZF750 and YZFIOOO; a nd two Buells, Ducati w as a d isa p poi nti ng last-mi n u te nosho w. Assi s tin g th e large co n tinge n t of Du nlop tech n ical representatives wer e to p AMA r oa d ra ce s q ua d s Kinko's Kawasaki, HyperCycle Suzu ki, Team Oliver Yama ha a nd Erion Racing Hond a. The race-team members se t up the s tock bikes' chassis for the race track and did much of th e tire swapping . In add ition, the sec o nd- tie r works teams offered their supersport eq ui pme nt for testing of the d ominant R model D207 DOT d ry-weather ra ce rubber. Honda provided the biggest selection of street bik es, while the Erio n crew had a total of five racers on hand. Dunlop USA's national sales ma nag er for Motorcycle Tires, Michael Buckle y , m ade the company' s intentions clear at Phoenix. "Globally, it's tremendously im po rta nt," explained Buckley of the street D207 radia l's introduction. "In Europe, the high-performance market segment creates such a pull-throu gh for all the other p roducts. In the Un i ted Sta tes, it's not as critical. because of our stro ng market sha re." Th e racin g version of the new tire , Du nlo p's 0207GP, made its official competition d ebut at Dayton a las t sp ring, and has dominated OOT-type racing in most countries aro und the wo rld. In the Un ited Sta tes, Jason Pridmore rod e a Suzu ki GSXR 750 to th e AMA 750 " Su pers po rt cro w n us in g the D207GP, M iguel DuHamel earned the AMA 600cc Su pers port title for H onda on 207s, a nd the N ASB EBC Spo rt Bik e crow n w e nt to Eri c Wood ' s Du nl op 0207GP-equipped Kawasaki ZX~R. For the first time in almos t a decade, Dunlop's consumer -o riented "s tree t sport" tires a re now based on the race rubber, w it h d evelopment of the tw o products taki ng p lace si mu ltaneo usly. According to the new tire's press materia l, th e D207 "offers rema rk able new technology and performance cha rac teris tics tha t set it d is tinctl y apart from both its pred ecessors and th competi.e tion ." Severa l d es ig n e le me n ts d e r iv e d from Dunlop's o ngoing slick and DOT racing development programs ar e integral to the D207 Sp ortm ax' s co ns true- tion . Dunlop calls the D207' s cosecantwa ve groove tread pa tte rn unique, and racing insi ders co nfi rm the pattern is d irectl y d erived from sli ck wear patterns . This developm ent is sa id to i m p ro ve stability a nd dramatica ll y reduce wear, allowing for softer compounds that improve both wet- and d ryroa d grip. Th e co secant gr oove sh ape fir st ap peared a t the 1989 Worl d Su perbike round in New Zealand, where a softcompound interm ediate racing tire won in wet conditions. The new street 0207 Sportmax u sed th e sa me ba s ic wave groove pa tte rn utilized on the D207GP racer. In an explanation that had most journalists on hand giving up on their not etakin g, Dunlop also ex plained its new s ty rene butadiene rubber (SBR) polymer-based com pounding. This contains fine-grain carbo n-blac k, aga in increasing grip while reducing wea r. This SBR is a new and ex pe nsiv e development formerl y fo u nd in race tires. mostl y slicks. On rear D207s, the SBR po lymerbased com pound is also reinforced with silica, increasing traction in the wet. CTCS is th e four-letter acronym for Du n lop' s new Carcass Tension Co ntro l System , anot her D207 breakthroug h. In race-tire developm ent, the carcass tension is revised con s tantly, and Du nlop explained that more tension on the sidewa ll and less tension across the tread face enhances stabili ty , handling and grip. This feat ure comes into play particularly at high -lean ang les , mai nt ain ing hei ghtened stiffness between the tire' s sho uld er and bead . The lower-crownarea tension e nhances ride comfort , ma king for a perfect tr ade-off in tire design. The net result of these developments is a tire that is better in every way tha n it s D204 s tree t predecessor. Wit h an increased contact pa tch at all lean angles, the tire is certainly more stable. These improvements are the result of an aggressive de velopment program by Dunlop's o n- track s taff in France and particular ly in Japa n. Du nlop designers confirmed in Phoenix that the new D207 Sportrna x has been test ed back to back with ri val manufactu rers' rubber, in stree t and road co nditio ns , as well as run against the racing D207GP. Th e to-tu m road co urse at Phoen ix In te rna tional is a good pla ce to tes t tires, its tight and twisty infield in sharp contrast with th e flat -out run through the fina l tum's banked oval section, better kno w n as N ASCAR turns number three and four. Th e infield ha s ha rd brakin g an d lo ts of p oint-and-sh oo t actio n, making precise s tee ring inpu t and feel vital. The fina l tum puts lots of heat into the left side of the tire, testing you r confidence, as any I OD-mph-p lus, lon g-time-lean ed -over , don' t-look-atthe-w all bend is likely to do. The high speed -en try, dou ble -a pexr decreasingra d iu s fi rst turn also keeps the rider bu sy d oing many th in gs at once, making traction and stee rin g stability paramount. Afte r we had a co u p le of sessions learning th e track, an o uti ng on the YZF600R go t us in th e mood for so me he a vy braking. The Yama ha showed great stopp ing performance as well as good leve r feel at the venue's two hairpins. Brakin g feedback from the D207's was great: Th e tires howled but never Jet the wheel lock up. As with Honda's CBR600F3, the Yamaha's steering was light and crisp through the infield, offering lots of confidence. Suzuki's GSX R750 pla ce d la rger demands on th e ru bber, provid ing more speed entering the daunting final tu m . The GSXR750 seemed tailormade for the new rubber. Even when a wide passing effort pu t me onto a less-used portion of the track, causing the front end to slide at triple-digit speeds, a bit more throttle and no panic kept the GSXR750 off the wall. Som e faster rid ers figured that th e rear D207s wer e a little too pron e to sliding at high speed on the big Suzuki, but