Dunlop Sportmax Q4 Test

The new Dunlop Sportmax Q4 aims to give a rider the maximum performance possible from a street tire, and Dunlop has thrown all of its considerable knowledge base into creating it.

The Q4 does not replace the Q3+; it is an addition to Dunlop’s Sportmax range of tires for those riders who demand the very highest performance from a tire that can also be used on the road, and who are less concerned about tire life.

Until now, if you wanted more grip than even the Q3+ could offer, you had to go to Dunlop’s GPA-Pro DOT race tire, and although those are technically street-legal and it might be tempting to try them, in reality, it’s almost impossible to get enough heat into a proper race tire on the road to gain any advantage.

Dunlop Sportmax Q4 Tire priceActually, it’s the reverse: while they’re warming up it’s like riding on ice and literally dangerous. I have several fast friends who tried using them in that scenario, and all of them ended up expensively regretting it.

So until now, we’ve only had the Q3+ available from Dunlop as a full-on sportbike tire.  Acclaimed as a tire with tons of grip, a stable nature—especially under hard braking; linear feel when going from upright to maximum lean; and a predictable nature overall. In fact, it is truly a street tire that also works so incredibly well on track that it blurs the line between those two disciplines.

For those street riders who also enjoy track days, it has the added benefit of a silica-based hard compound centerline that helps it reach a very acceptable rate of wear as well. Wet weather grip is phenomenal too, so overall, the Q3+ is judged by many to be as close to the perfect sportbike tire as it’s possible to get. Personally, I have found I can get three track days and a bunch of road mileage from the Q3+, so I have zero complaints—and I’m not alone.

Having said that, it is still a compromise and as riders, we don’t easily fit into that ‘one-size-fits-all’ container. Dunlop personnel realized that there is a significant number of street riders out there who are also hard-core track riders, and they are skilled enough at the craft that when they do a track day they run at the sharp end of A Group, and as good as the Q3+ is, they need an uncompromising tire with phenomenal grip. They prioritize performance over tire life, and feel that a few hundred bucks each year is neither here nor there if they’re getting the very best out of their bike and skill level. Going fast is expensive.

So Dunlop developed the Q4, to fill the gap between the sticky Q3+ that gives a nod to long tire life, and the GPA full race tire that truly needs racing speeds and tire-warmers to work properly.

Of course there is also a segment of rapid street riders who do fewer track days but also value the very best performance over tire wear; this group will point out that better grip increases safety, and it’s tough to argue against that. Even a low speed get-off can be very expensive, and cheaping out on tires is always a false economy.

But, truth be told, the number of riders out there who can truly ride to the edge of the Q3+ grip envelope is fairly small; and as skilled as I like to think I am, if I’m honest with myself, frankly I don’t fall into that category either. I can get close-ish to the Q3+ performance limit on track, and never in the canyons. I don’t love sliding tires, and once they start to move around a bit and get that greasy feeling, I tend to tap out. Oh well.

So when Dunlop announced the Q4, I was intrigued. With the Q3+ not truly holding me back as a rider when I’m on track, I couldn’t help but wonder if the Q4 would be wasted on me. I doubted I’d be any faster. As it happens, I’d have a direct comparison, because thanks to Ken Tam and Foothill Ducati Owners Club (FDOC), I had recently ridden our long-term Suzuki GSX-R1000R, shod with new Q3+ tires, at Chuckwalla Raceway in the So. Cal desert—the same location as the Q4 launch.

I’d spent the day chasing around at a very respectable pace (or so I’m told). 2:06 laps around Chuckwalla are laughably off race pace, but for a track day with buddies, those are still A-Group times, albeit at the slower end. But hey, still A-Group, right?

Now that I had the opportunity to try the new, less-compromising Dunlop Q4 at the same track, on the same bike, and only a few weeks later with similar conditions, I’d have a close to direct comparison with few variables between the two tire models. I couldn’t wait.

Dunlop provide the spec-tire for all classes in MotoAmerica, and the Moto 2 Championship race series (among others) as well, so they have enormous experience on how to create the very best race rubber. Since the Q4 aims to give the maximum performance possible from a streetable tire, Dunlop has thrown all of that considerable racing knowledge into it.

Dunlop Q4 Rear after 1 track dayThe first thing you’ll notice visually with the Q4 is the relative lack of wet-weather grooves; the land/sea ratio of the Q4 just squeaks into the legal side of street-legal, and visually the tire is not that far from being a slick. The single, soft compound of the Q4 is made from a highly complex recipe of carbon-black only (so no silica, same as Dunlop’s race slicks) for maximum grip.

It is constructed using Dunlop’s same Jointless Tread (JLT) technology that winds a single, seamless ribbon of rubber continuously around the carcass, so there are no joins. Also, there are no multiple compounds that can upset the tire’s handling where those compounds transition. JLT increases tire stability and reduces flex, and it creates a larger, more consistent footprint during braking, cornering and acceleration. It also saves around one pound in weight over the same size Q3+, so there’s less mass for improved acceleration.

Heading out on to track, the Q4 immediately felt different. Even on my out lap I could feel the Suzuki GSX-R1000R was going to maximum lean quicker, and I was clearly carrying more lean angle as my knee was touching down in most of the corners. When I got home and compared my GoPro video footage I discovered that on the Q4 I had a massive 4.27 second a lap improvement in lap times.

I rarely reach the limit of Q3+ grip even on track, so I doubt I was near the limit of the Q4. Therefore, it appears that only minimally allowing for the extra grip of the Q4, it was the function and handling of the Q4 tire alone, that made me quicker.

Now 4.27 seconds is a huge difference, and I do not claim that others will see the same improvement. For complete transparency sake, although the track and bike were the same, I had added four turns of preload to the rear shock to help the handling on acceleration, as recommended by John Ethell at JETT Tuning, Camarillo, and there was a noticeable improvement. Also, because the days were almost 2 months apart there were differences in both myself and the track conditions.

So I can attribute quite a bit of the extra speed to those factors. Nevertheless, the Dunlop Q4, for me, is a definite improvement over the Q3+, and I could easily feel it. I can go significantly faster on the Dunlop Q4, without a doubt. [see video for comparison]

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Because the Q4 is a street tire, one Dunlop design goal insisted that warm up times should be negligible, and Dunlop Q4 tire engineer John Robinson (and a serious track rider himself) has achieved that. Dunlop claim that tire-warmers are not needed, and newly hired MotoAmerica Superbike pro test rider Taylor Knapp, said that at the recent MotoAmerica Barber Superbike test he didn’t use them. Apparently the expression on his factory-rider rivals’ faces when he simply pulled in after a session and parked the bike with no warmers, was interesting!

I’m always a little cautious on a track with cold tires, however since the temperature at Chuckwalla was so hot (it hovered around 100 degrees all day) I wasn’t concerned and gave it the full beans after about 3 corners, with no ill effect whatsoever. Needless to say I would be more circumspect in colder ambient temperatures; but even so, it’s impressive—and useful—to not have to go to the aggravation of using warmers at the track. I have no idea how this will affect heat-cycling and the life of the tires; that remains to be seen.

Dunlop recommends that Q4 cold pressures should be 32 psi front, and 30 psi rear, so that’s what we were running. The Q4 uses Dunlop’s proprietary Carbon Fiber Technology (CFT) in the sidewalls, same as that with the Q3+, and it helps achieve the Sportmax tires’ exceptional stability, both on the brakes and at high lean angles.

CFT places a carbon fiber reinforcement element in the tire sidewalls and bead, and the stiffness it gives the tire gives the Dunlops their exceptional feel, especially with the front under hard braking. Because there’s little to no squirming with Dunlop Sportmax tires, the feel I get is feedback from the track surface; I can tell what the front is doing. It does mean that the somewhat bumpy Chuckwalla surface did get transmitted through to me, but I prefer that to the slightly squishy feeling I have felt from other brand tires.

Chuckwalla has a couple of short-ish straights. The one going past the pits ends in a funky chicane that requires some hard braking from around 130 MPH, through a very slight left and over the curb, and into the slow-ish right hander of Turn 1. Coming into that section, I felt confident enough in them to brake later and harder than I do on the Q3+ tires.

Dunlop’s Intuitive Response Profile (IRP) creates a larger corner patch when leaned over, and the Q4’s taller tire profile and aggressively tapered sides help the bike transition to maximum lean angle faster than the Q3+. This was perhaps the most noticeable aspect of the Q4s for me at Chuckwalla. The Suzuki GSX-R1000R went to maximum lean noticeably quicker than on the Q3+ tires, and that allowed me to turn in slightly later and carry higher entrance speed.

Dunlop Sportmax Q4 Tire testThis is especially noticeable in the blind, over-the-hill combination of Turns 8, 9, and 10, as it requires flipping from the relatively slow knee-down left of T9, down the hill and over to the T10 right-hander, which opens up and begs for aggressive acceleration.

I have always felt I go through there decently on the Q3+ tires, but on the Q4s I knew I was a lot quicker, and it didn’t take any extra physical effort to achieve it. I simply went through the whole combination faster, and a couple of times I found myself running a little wide out of T10 such was the extra speed I was carrying.

Happily, the Q4s do not make the Suzuki flop into corners; the Dunlops still retain that super-linear feeling of the Q3+ as the bike starts to lean; I love the neutral, predictable, handling of those tires and I was extremely relieved that the Q4s aggressive profile hadn’t lost that controlled lean.

Taylor Knapp took part in the recent Dunlop tire test at Barber Motorsports park on a stock Suzuki GSX-R1000R that only had a replacement exhaust system, and Q4 tires. Running in the Superbike class against the current crop of factory riders and bikes, Knapp (incredibly) managed to post top ten lap times against guys on factory bikes with slicks. The data later showed he was achieving an astounding 62 degrees of lean angle on the Q4 Dunlops.

I cannot claim to even come near that level of lean—frankly, 62 degrees seems way too close to the 90-degree horizon and I have no intention of going there. Having said that, I knew I carried more lean angle around Chuckwalla than I ever had on the Q3+ tires. I was dragging knee around most of the corners, and I rarely do that, and through the infamous long bowl of Turn 13 I dragged my knee all the way around with ease. Coming hard on to the gas out of that turn, the rear end started spinning a little, and although that normally indicates that I’m at my limit, I felt surprisingly comfortable doing it on the Q4s.

The Q4 also fills some gaps in Dunlop’s sizing, with these tires being available in not just the conventional 180 and 190 rear sizes, but also in a 180/60 size for 600 riders, as well as a 200/55 size that will keep Italian motorcycle owners happy too.

Dunlop Sportmax Q4 Tire ProfilePricing obviously varies from outlet to outlet, but in general, will be around 10% to 15% more expensive than the Q3+ from the same retailer. To give you an idea, a 190/55 Q3+ retails for around $185, and the same size Q4 will retail for around $210.

The end result of my day at Chuckwalla is that the Q4 tire is a noticeable performance improvement on track over the Q3+, a tire I am particularly fond of. Since I’m not quite fast enough to really explore the limits of the Q3+ grip, I was surprised that the Q4 made such a big difference to my lap times.

Even taking the variables into account, clearly the Q4s were likely responsible for at least a couple of seconds a lap improvement over the Q3+. The added confidence that the new Q4 gave me made an enormous difference, and that must have contributed to a lot of it as well.

I have subsequently had a chance to ride the same Q4s fitted to the Suzuki on the street. This past weekend I went on a high-speed canyon ride with friends, and we covered well over 250 miles. The Q4s felt the same as on track; super-grippy and confidence-inspiring, and quick to react on corner entry without allowing the bike to flop-in. The wear is reasonable and I’m still not down to the wear bars on the rear.

Whether a couple of seconds a lap on the Q4 is worth trading away the longer life of the Q3+ is entirely a personal, and highly subjective to each individual. Results will vary from rider to rider, obviously, but I applaud Dunlop for filling the gap in the Sportmax range of tires and giving us this choice.

I’m sure there will be a lot of people who will greatly welcome the Q4 as the ideal tool to help them extract that extra speed on track, and even those who aren’t quite as fast and don’t ride quite at the edge of the envelope, will welcome a tire that improves confidence even over the amazing Dunlop Q3+.

Photography by Brian J. Nelson

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