Building the perfect sport-touring motorcycle is basically an impossibility, because every rider has a different idea of the ideal balance of sport and comfort, and nobody wants to compromise.
The same applies to tires.
“Performance touring is the hardest segment to engineer a tire for,” said Mike Manning, Dunlop’s marketing director. Riders want longevity, especially those who travel a lot, but they still want good grip and feedback when they get to the good roads.
Manning noted that although motorcycle tire sales overall are down in the U.S. market, sport-touring tire sales are actually up, as owners of performance bikes realize that the newest sport-touring tires provide almost the same grip as sport tires (or better grip, in some weather conditions) but last a lot longer. That makes the new Sportmax Roadsmart III an important entry in Dunlop’s lineup.
Two objectives for the Roadsmart III
For the third generation of the Roadsmart, Dunlop had two goals and one target. The target – the benchmark they measured their new tire against – is the Michelin Pilot Road 4 GT, not just because the Michelin is an excellent tire, but also because riders were buying more of them than the Roadsmart IIs.
The two objectives were to provide greater mileage and to engineer a tire that retained its good handling characteristics longer. So a key part of the testing done by Dunlop at its test center in Huntsville, Alabama, and by an independent firm, Texas Test Fleet, on the road, involved not new tires, but Roadsmart IIIs with 3,000 and 5,000 miles on them. After Texas Test Fleet put 5,000 miles on the tires using BMW R 1200 RTs, Dunlop test rider and former Superbike racer Rich Conicelli tested them on the Dunlop track, which simulates all kinds of conditions found on the road: wet, dry, braking, curves, bumps, etc.
As Dunlop engineer Shawn Bell put it, what’s the point of having a tire that lasts a long time if it doesn’t maintain good handling? You just end up doing more miles on a poorly performing tire that you don’t enjoy.
Data acquisition captures variables such as speed and lean angle while Conicelli is testing. The end result, Conicelli said, was that he was able to lap the test track about three seconds quicker on the worn Roadsmart III than on the worn Michelins, which is a big difference on a short track where laps are about 40 seconds. Dunlop says the Roadsmart outperformed the Pilot Road 4 in both grip and cornering, with a bigger advantage in wet conditions.
As for longevity, Texas Test Fleet created estimates based on their testing at the 5,000-mile point and predicted a front Roadsmart III would last more than 20,000 miles and a rear would last about 13,000 miles.
Construction, compound, pattern
Those are the three aspects of tire construction and Dunlop made changes to each with the Roadsmart III. In terms of construction, the sidewalls are slimmer for better damping and the winding of the strands that make up the steel band (Dunlop’s jointless band, or JLB) that runs longitudinally around the tire was changed. These alterations made the tire more compliant, and then to compensate and maintain the neutral handling characteristics Roadsmarts are known for, the radius of the rear tire was changed slightly, Bell said.
Both front and rear Roadsmarts continue to use dual compounds, with a more durable mix in the center and a softer compound on the sides. When upright, the rider is completely on the durable compound and at a 30-degree lean angle is entirely on the softer compound.
Finally, the tread pattern is completely changed. On the Roadsmart II, there were no grooves that overlapped. The Roadsmart III tires have overlapping sipes of different widths which are meant to make it easier for water to escape from underneath the contact patch.
Riding on the Roadsmart III
Dunlop had a small fleet of BMWs and KTMs for us to try their new tire and I ended up aboard an R 1200 RT. Instead of the rain plaguing California lately, we got lucky and had a beautiful, 60-degree sunny day for the ride in the hills north of Los Angeles. The downside is we didn’t get to test the Roadsmart in true wet conditions. Due to the recent weather, the roads did throw some challenges at us, however, with dirt and mud washed across the pavement in many spots, a few damp patches in the morning and occasional spots where water was flowing across the asphalt. That put a premium on predictable handling so I could choose a line between obstacles that appeared around many corners.
Based on a short day ride on brand-new tires, it’s impossible to evaluate how Dunlop did in achieving its two objectives: greater longevity and better handling after the tire is used. What I can say is the Roadsmart IIIs have all the positive characteristics of their predecessors and, subjectively, felt to me like they provide both better grip and feedback. Starting off in the morning in cool temperatures on tires that had zero miles on them and on an unfamiliar motorcycle, I was a little hesitant. But by the afternoon, I’d learned to trust the tires and was riding with much more confidence as I picked my way through the post-flooding obstacles.
Though we didn’t have soaked pavement to test the wet grip, on the many instances where we rode through water flowing across the road, the tires didn’t even wiggle. They seemed not to notice the change in surface.
One of the things I have liked about the previous Roadsmarts is their neutral feeling, or what some call linearity. A given amount of input yields a predictable amount of turning, instead of suddenly tipping in further in a corner or wanting to stand up. The Roadsmart IIIs retain that trait, and it’s one Conicelli said he specifically pushes for.
Given the conditions and the short length of the ride, I never pushed the limits of the tires. Frankly, to do that, I’d want to be on a track. It’s impressive that today’s sport-touring tires can give you levels of grip that would have been good for sport tires in the past while promising a 20,000-mile life.
A question and a personal observation
That raises the question: Will the Roadsmart III really give you 20,000 miles from a front tire and still handle well after it’s half used up? Only long-term testing will answer that for sure. And while I almost hesitate to bring it up, because it’s merely a single, outlying data point, I can give you an example from personal experience that may be interesting.
I had Roadsmart II tires on my personal Kawasaki Versys 650. It’s the bike I use whenever I have to do one of those 500-mile days from my home office to ZLA HQ. When it came time to replace the front tire last year, I was shocked when I looked at my tire log and saw that I had ridden 25,000 miles on that tire. I double- and triple-checked my records because I was sure that had to be a mistake, but it wasn’t.
I’m not saying you should expect to get that kind of mileage. That’s a fairly light bike that I don’t usually push very hard. But if the Roadsmart IIIs live up to their claim of better longevity than their predecessors, even some long-distance riders will be able to avoid the hassle of changing tires every year.
As sport-touring tires keep getting better and better, it’s no surprise that even sport bike owners are switching. It’s not just the cost of replacing sport tires that might wear out after just 3,000 miles or so, but also the time lost and the hassle of getting to a dealer to have them mounted, if you don’t do it yourself. Unless you are riding a serious pace at track days, the latest sport-touring tires will give you all the performance you need for street riding and will hold up better to your occasional trips and daily commutes.
I suspect I’ll put a set of Roadsmart IIIs on one of my personal motorcycles fairly soon. When they’re used up, I’ll let you know how they did. But if Dunlop’s promises come true, you’ll have to wait a while for that report.