Dunlop Sportmax Q4 Review

words: willy-joe, photos: ‘BRAIN’


Brian J Nelson

We motorcyclists can be an onerous, demanding bunch. For our motorcycles, qualities include, but aren’t limited to: lighter, faster, more sophisticated, more durable and simple to use. Largely, the manufacturers have obliged, even indulged, our demands. For our tires, we place demands on manufacturers for performance characteristics that can be argued to be in direct conflict with each other. We want a tire with ultimate grip, great durability, stability, a compliant ride, quick warmup, and good wet weather performance. Oh, and it can’t break the bank, because, you know, we got our eyes on that titanium exhaust system and 520 chain conversion kit.

 

Back in the day – in 2013, the Soup staff sampled Dunlop’s Q3 at their Huntsville, Alabama proving grounds. Lined up next to its Q2 predecessor, the contrast against the new and improved Q3 was obvious, and the Q2 passed the baton to its successor. During the following four years, Dunlop’s Q3 built a large and enthusiastic following. Then, in the first quarter of ’17, Buffalo’s Dunlop crew sprung the Q3+, delivering slightly better grip, and yet more durability. After the four year stint with the Q3, you could safely bet that cycle was set to repeat. You’d have lost that bet, because as the Q3+ was being released, development of a new tire had already begun. Was it another evolution of the Q3? More silica? new tread pattern? Not this time. Dunlop noticed something about their sport tire line up, that a part of the marketplace was not covered – the dedicated track day enthusiast. The Q3+ is a capable partner for the occasional track day attendee who also commutes on the same bike and tires, but they do have limits, seeing as how they’re built primarily as a street tire, and as such, are expected to prioritize other performance parameters for this environment.

Enter the Sportmax Q4, a tire designed and built to prioritize race track demands, while also being streetable. It fulfills a different role to the Q3+, and so it is an addition to Dunlop’s lineup, not a replacement of the Q3+. There’s no silica, and there’s precious little grooving, but enough to satisfy DOT street tire regulations. The same, single compound of pure carbon black rubber of Dunlop’s own formulation covers front and rear carcasses, but how they’re applied depends whether you’re talking front or rear tire.

The Q4’s development included multiple rubber compounds, profiles, etc. The tire was tested at several tracks around the U.S., including but not limited to, VIR, Roebling Road, and the site of today’s intro, at Chuckwalla Valley Raceway. Lead test rider, Taylor Knapp, a MotoAmerica superbike racer as of the end of last season, has been principally responsible for development feedback on the tire’s performance before going into production.

With nearly every new tire introduced, new acronyms are created to describe the magic used to create it. The first batch of letters is applies to front and rear. Dunlop’s proprietary Carbon Fiber Technology (CFT) is used in the sidewalls, to bolster stability at high lean angles, and increase steering precision. This isn’t a unique element in the Q4, as it also was used in the Q3+. The next is exclusive to the rear tire. JLT, or jointless tread technology. Dunlop’s special machine applies the rubber for the tread in a continuous, narrow bead of rubber applied to a rotating carcass across the width of the tread. Precision of this application method is measurable down to the tenth of a millimeter. This precision allows Dunlop’s Buffalo crew to achieve specific characteristics for tread stability, flex and grip from center to edge. As the name implies, there is no joint in the tread. Instead, the narrow beads of rubber are barely visible when the light shines just right on the tread. A benefit of this technology is the rear tire is about a pound lighter in weight. This helps with suspension setup, and improves acceleration and deceleration. Whenever you have a chance to reduce unsprung weight, like this, you should take it. IRP, or intuitive response profile, is further narrowed to specific rear tire sizes – 180/60 and and 200/55. At the risk of oversimplification, IRP creates a taller tire that more aggressively tapers the sides. This in turn creates a larger contact patch at full lean, which has helped make possible 62 degree lean angles. With this last tidbit in mind, the Sportmax Q4 logo is tauntingly molded into the edges of the front and rear tread. Before despair sets in over the front tire not getting this same love, investigation into using the same methods as used on the rear would not yield the same benefits, and so it’s construction remains a cut tread design. Essentially, this can be taken to mean it was already awesome, and the rear tire needed to catch up.

Brian J Nelson

Now, for the fun part. Riding the latest hyper sport machinery, on the latest tire technology at one of the more bitchin’ tracks in California Chuckwalla Valley Raceway. It certainly sounds good to be turned loose on equipment you didn’t pay for to find the limits of Dunlop’s latest offering, but attached is a great responsibility. You’re expected to get a deep sense of the product’s ability, but the people making the event possible by pitching in with time, expertise and equipment would rather not see yard sales involving motorcycles from the big 3 out of the four Japanese OEMs. I’d rather not end up telling the EMT what day it is, or how many fingers they’re holding up while I remain in the supine position. With this in mind, I reminded myself I was last at this track in 2013, riding it in the opposite direction, that I have no recent experience aboard any of these shiny examples of corporate supersport and superbike pride, save the old school GSX-R600. Add that there was a healthy layer of trackside sand lurking within the grain of Chuckwalla’s asphalt, only made visible by the motorcycle ahead of me as we peeled into turn one, creating a ‘wake’ not unlike what you see from a boat. Throw in an occasional dust devil, just to make it a little more exciting.

We started circulating at 8 a.m., to beat the expected heat – it was 108 the day before. Also, with the heat in mind, the tires were filled with nitrogen, and pressures were set at 32 front, 30 rear. Street pressures could be upped to 34 / 32, respectively. I started off with the R6, which at the time had the standard 180/55 rear fitted. While I played connect the dots in the corners, alternately accelerating from too slow corner entry to massive trail braking into corners and massively running wide in the first session, I gradually tidied up my lines and moved my braking markers closer to turn in points. Through all the wandering, hack riding, the tires performed the same, no matter which bike I was aboard. Steering precision was absolute, and feedback from the contact patches were clear, whether I was smearing the front with the brakes, or making up for lost corner speed with rear grip, they tolerated my ham-fistedness while giving me a solid platform from which to regain my form. Turns 4 & 5 are connected through a double apex line, and while getting up to speed, I had opportunity (necessity, truth be told) to follow different lines, and adjust lines, and the Q4s never protested, not even over the bumpy entry into turn 6. Later in the day, the R6 was fitted with the 180/60 rear tire, and the difference in feel was immediately noticeable. Steering was quicker, but remained stable in all situations. The ZX-10R was fitted with the 200/55 rear tire, and I expected the same behavior as the 180/60, but I crested turn 9 on the second lap, the rear stepped out enough to convince me to slightly roll back the throttle. Immediately following, in turn 10, that I was enjoying dialing in throttle throughout its arc, the rear again issued its warning. Hmm. Kind of a buzz kill. Is the sand an issue? Doubtful, given the front’s stellar performance, but maybe it’s due to the massive shove provided by the engine that’s not being adequately tamed by electronics? Admittedly, I’m just hopping aboard these bikes, and only adjusting brake lever spans. Maybe it’s just that I got it toward the end of our track time, and it was shagged from the previous sessions.. After I came in and gave my feedback about the rear tire, I didn’t see anyone else take it back out. Later, other journalists described similar behavior in regard to the 200/55’s edge grip. This was the only complaint I heard anyone utter about the Q4. Lots of praise for the effect of the 180/60, was noteworthy. Speaking generally, the tires performed exactly as they were designed. I was railing in a little over a half lap from pit exit on “cold” tires, and while I didn’t tempt fate while attempting a 62 degree lean angle, neither did I leave any trace of Dunlop’s logo on the tread. I did however, leave lots of rust out on the track. Thanks to the new Q4, my drama was limited to sloppy lines and a few wide-eye moments known only to me (“I meant to go really wide, there….”).

Brian J Nelson

As a side note for the technical side of things, with anti-lock brake systems and traction control behavior following the direction of algorithms based on many parameters, including tire circumference, if you’re riding an unmodified R1 / GSX-R / ZX, which are delivered wearing a 190/55 rear tire, the jump to the 200/55 didn’t seem to cause any glitches in the ‘if / then tables in their black boxes. It’s less clear with Honda’s setup. The CBR comes fitted with a 190/50. Jumping to the 200/55 theoretically may cause the CBR’s black boxes some confusion, if the extra circumference of the rear hoop manages to venture to beyond the acceptable delta of front/rear wheel speed addressed by Honda’s algorithm’s. Questions about this during the presentation left the issue for a Honda murky, as Dunlop had not used a ’17 CBR1000RR during its testing phase and there was not one present for this intro. Ultimately, the suggestion to turn off traction control was the last option offered. I followed the instructions in the Honda’s manual for this, but I could only get the lowest setting, not turn it off. Honda has a HRC black box that assuredly will address this issue, but unless you’re well connected, or are deemed a worthy race effort, you won’t have the privilege of paying lots of money for it and the attendant wiring harness that removes key elements for street legality. If I were to fit the Q4s to my own CBR, I would fit the 190/55, and avoid the possible ‘glitches’ the 200 may cause. This may be much ado about nothing, an example of overthinking the issue, but the lack of definitive data, or experience providing needed answers, there remains nagging doubt hanging over the CBR.

There was noticeable wear of the tires on all the bikes, naturally, it was more pronounced on the liter bikes. With the exception of the 200/55, there didn’t seem to be appreciable falloff of traction levels at the end of the day. I would expect the new Q4 to go 3 track days, perhaps four, depending on heat conditions, and abrasion characteristics of a given track.

The Q4 is available now, through your favorite retail source. Pricing of the Q4 will be 10-15% higher than what you’ve paid for the Q3+.

Brian Nelson the Best Photographer Ever

 


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