Dunlop Roadsmart II Sport Touring Motorcycle Tire Test
With the advent of the sport-touring category of motorcycles, and sportbike manufacturers upping the horsepower ante with each new model, owners have become more demanding of their tires.
Mike Manning, Dunlop’s Marketing Manager, told us that “sport-touring tires are the most challenging to develop, simply because they’re required to last well, but riders aren’t prepared to give up any grip either.”
Faced with this challenge, Dunlop has launched its next-generation Roadsmart II sport-touring tire that provides dramatically more grip, longer mileage, and greatly improved wet-weather performance.
We tested the new Roadsmart IIs on an eclectic variety of sporting motorcycles in quick succession, from the sporty Suzuki GSX-R750 and Yamaha FZ8, through to the relatively hefty BMW K 1600 GTL and Kawasaki Concours. Despite the huge differences in weight and power, impressively, the Dunlops maintained the same feel from machine to machine.
On fast roads that I know well, the grip and linear handling of the tires proved to be exceptional. Dunlop Flex-Steel/Jointless-Belt construction maintains the Roadsmart II’s hoop strength so they don’t squirm, yet also keeps the sidewalls flexible enough to allow the suspension to work properly.
Through one particularly fast turn, I hit an unexpected bump that banged the left side down hard enough to unsettle the chassis. I was thrown off line and the front had every reason to let go, but it held firm and I was able to bring the bike back.
The Roadsmart IIs have a slightly thicker carcass than Dunlop’s brilliant Q2s (winner of our track comparison last year), so the heavier tire weight means that bumps are a bit more noticeable on the lighter sportbikes, though less so on the weightier machines. Dropping the pressures down to 34 psi front, 36 rear on the Suzuki GSX-Rs solved the problem.
The unprecedented grip and linear feel from the Roadsmart II is thanks to a combination of Dunlop’s Intuitive Response Profile (IRP), new silica rubber compounds, and their Multi-Tread technology. The IRP enables the tread footprint to grow as lean angle increases, yet it stays consistent, so the excellent turning ability and feel of the tires is not compromised.
The rear tire incorporates Dunlop’s Multi-Tread technology, with softer rubber compound on the shoulders for extra grip.
Although the signature cosecant-curve tread pattern is still there on Roadsmart IIs, the number, depth, and placement of the rain channels have changed, increasing tire life and improving water dispersion. Because the grooves do not cross the centerline on the rear tire, stiffness is increased and this contributes to the extra mileage. Grip in the wet is claimed to have dramatically improved, with lean angle capability going from a creditable 37 degrees to an amazing 43 degrees.
Dunlop’s Roadsmart IIs are a significant improvement in grip and handling; the fact that they work so seamlessly and on such a wide variety of machines is impressive indeed. It seems that Dunlop has now given hard-riding sport riders that elusive combination of superb grip and feel, without sacrificing sensible tire life.
