Michelin has unveiled its second-generation 2CT (Two Compound Technology) all-purpose high performance sportbike tire: the Michelin Power Pure.
The Power Pure is the French manufacturer's latest successor to the popular Pilot Power series introduced in '04, which was then followed up by the Pilot Power 2CT in '06. Both tires have since been a solid choice for many hardcore enthusiasts looking for a sportbike tire offering the best compromise between high performance grip in the dry and quicker warm-up with adequate water displacement in the wet.
Michelin engineers holistically designed the new Power Pure from the ground up with one objective in mind: "To manufacture the lightest two-compound sport premium tire ever conceived." Michelin has achieved that goal by implementing what the company calls Light Tire Technology, or LTT.
LTT incorporates the latest in 100 percent synthetic materials combined with a wholly new approach to tire manufacturing-some of which Michelin is keeping a secret.
What Michelin will tell us is that for this category it has found a new way to make both front and rear tires require only three Aramid belt plies each (Aramid fibers being 10 times lighter than steel but just as strong), as opposed to other sportbike tires which to date need at least four or five plies to work properly.
Unlike conventional tire construction that requires four or five plies in order to obtain the necessary carcass stability and integrity, the new Michelin Power Pure sport tires utilize only three Aramid belts in both the front and rear tire carcass. This design breakthrough results in a significant reduction in tire weight, providing major handling benefits due to less unsprung weight and rotational mass that are very comparable to the same you would get from expensive aftermarket wheels and brakes.
This reduction in belt plies when married to the newest synthetic silica-infused tire compounds saves a whopping 1kg (or 2.2 pounds) in total weight savings per pair of Power Pure tires when compared to comparable sets from Pirelli, Bridgestone, and Dunlop. This is a considerable weight reduction that pays huge dividends in handling terms.
It's common knowledge that all race teams (as well as street riders) spend a good amount of money to replace stock road wheels and brake rotors with lighter magnesium or carbon fiber units in series where such modifications are allowed. The reduction in unsprung weight allows the suspension to react quicker to road irregularities, while the reduced rotational inertia allows quicker acceleration and less gyroscopic effect for quicker changes of direction and more precise steering.
Compared to the previous Pilot...
Compared to the previous Pilot Power 2CT, the new Power Pure (top) has significantly more soft compound rubber over the profile of the tire, especially in the rear. This dramatically increases the amount of soft compound in the tire's contact patch as the bike is leaned over. For example, at a 36-degree lean angle, the Pilot Power 2CT still doesn't have any soft compound rubber in the contact patch-meanwhile, the Power Pure front tire's contact patch has 28 percent soft compound at that point, while the rear tire's contact patch already consists of 100-percent soft compound rubber.
Michelin, for its part, discovered with the help of its near $700 million annual R&D budget last year (since being forced out of MotoGP due to the recent spec tire rule) that less rotating mass and unsprung weight on a modern sportbike tire not only provided the aforementioned benefits, but also minimized load fluctuations between the tire and the ground that result in the dreaded chatter, where the resonant frequencies between chassis and tire overcome their self-damping characteristics, causing it to bounce rapidly. When applied to the real world with real road riders, lighter tires can and do very simply make a motorcycle more fun to ride.
Michelin points out that because the tire carries its weight the farthest distance from the axle, when the tire is lightened, it can have a more profound effect (gram for gram) over aftermarket wheels or brake rotors-without the exorbitant added expense.
Tread depth remains unchanged with the Power Pure over previous models in this category, so the life of the tire is not adversely affected by the new manufacturing technique.
We had the opportunity to test a bike back-to-back through one of the chicanes at Spain's superb Circuito de Almeria racetrack with weights added to the rims, then removed, to simulate the exact difference in performance between the older, heavier Pilot Power and the new Power Pure. There was a noticeable difference, to be sure; the bike changed direction fractionally quicker and with less effort with the extra weights removed.
Another goal for developers was to make their new tires safer by offering superior side grip, sooner. This was realized by creating a new 2CT version, which sees the Power Pure's proportion of soft rubber compound increased on both the front and rear tires, when compared to the Pilot Power 2CT.
But, what does it all mean, Basil? Do they work? The answer is a resounding yes.
It rained on the Almeria circuit up until our first session, so my first impression of the Power Pure tires would be on a wet racetrack. "Just don't scratch the motorcycle," I kept saying to myself. But I soon found myself in disbelief when I was shortly thereafter attaining lean angles that were enough to have my knees casually scraping along the wet pavement. If you had tried the same lean angles just a couple years ago with cold DOT tires, you would've found yourself on your head. As the pavement dried up by the afternoon, the Michelin's performance didn't; overall grip and handling were superb by sport tire standards, with excellent trail-braking characteristics right up to a 9/10ths pace, at which point a racer would probably desire just a bit more stability in the carcass and compound durability. But again, these are intended as sport tires that can handle track days, not a full-on DOT race tire.
Later, we rode a 100-mile loop in warmer and dryer weather around the canyon roads of southern Spain. As expected, performance was much of the same; the tires were stable at high speeds and nimble in the canyons with excellent grip.
The mad scientists over at Michelin have blown us away with their latest-generation Power Pure sportbike tires. They're good-very good.
The Michelin Power Pure will be available in the usual sportbike sizes (120/70ZR-17 and 120/60ZR-17 fronts, 160/60ZR-17, 180/55ZR-17, 190/50ZR-17 and 190/55ZR-17 rears); pricing was not available at press time. - Mark Miller