Motorcycle.com

What if a tire manufacturer told you that their new street tire had the performance chops to take 3.5 seconds off the best lap of the previous-generation tire at Spain’s Circuito de Cartagena? That’d get your attention, right? It got mine, but then again, I was sitting in a press briefing in one of the pit boxes at the Losail International Circuit so soon after the first MotoGP of the 2017 season that the rider name boards were still in place.

The tire in question was the new Michelin Power RS which is slated to replace both the Michelin Power 3 and the Michelin SuperSport Evo. I can hear the questions now. Yes, we were testing a street tire, not a street-legal track tire, on a circuit known for its high cornering speeds – and that’s before we consider the 3504-foot front straight on which Jorge Lorenzo set a 351.2 kph (218.2 mph) record in 2016. Michelin must be pretty confident in the performance of the Power RS.

With a 6.5% land/sea ratio, the Power RS almost looks like a slick. The dry edge grip is enhanced by the lack of grooves on the edge of the tire. Note that the highest percentage of siping is around 32°, an angle Michelin says is near the maximum angle leaned over in the rain.

If Michelin’s track choice didn’t exude confidence, the fact that its hyperbole machine was set to 11 sure did. Yes, product introductions are times that manufacturers feel free to puff up – perhaps even overstate – their product’s capabilities to a captive audience, but Michelin reps declared that the Power RS was the “perfect tire” and that its release represented a “watershed moment in the history of motorcycle tires.”

These are huge claims, but they were bolstered with the results of independent testing at the Motorrad Test Center at both the Boxberg and Neuhausen circuits on October 2016. On a BMW S1000RR shod with 120/70ZR17 front and 190/55ZR17 rear, the Power RS purportedly bested the Bridgestone S21, Continental Sport Attack 3, Dunlop SportSmart 2 (not available in the U.S.), Metzeler M7RR, and Pirelli Diablo Rosso III, apparently in every performance category tested.

Technicalities

According to Michelin, sport riders are interested in three things: dry grip, agility, and stability. To meet those ends, Michelin utilized its ACT+ (Adaptive Casing Technology) architecture, to create a softer crown while maintaining a stiff sidewall. When accelerating in a straight line, the tire’s 90° casing maintains the tread’s suppleness for a wobble-free ride. This same 90° casing wraps around the bead and doubles over on itself, giving the sidewall the stiffness necessary to handle cornering forces. When developing the tires, the optimal amount of overlap was sought to provide the best matching of center suppleness with sidewall stiffness.

With Michelin ACT+, the 90° belt wraps around the bead to double-up the layering, thereby increasing sidewall stiffness.

Two different approaches were taken on the dual-compound rubber. On front tires, the engineers utilized Michelin 2CT (Two-Compound Technology). Since the company first utilized dual-compound tires in 1994 on 500cc GP bikes, it knows a thing or two about combining compounds. In the 2CT front tires, the tread’s all-silica crown provides grip in wet conditions while resisting wear from braking. The center 68% of the tire uses the silica compound, while the 16% of the tire on either side of the center generates grip through the use of an all-carbon-black compound.

The rear tire uses 2CT+ which, as with the 2CT, places the all-silica compound in the center and flanks it with the all-carbon black. However, the construction and percentages are different. The crown’s center 54% receives the silica compound, but it doesn’t stop there. It also forms a stiffening layer that passes below the two 23% sections of the carbon-black compound on the tire edges. This additional layering helps to create the rigidity necessary to handle the forces of accelerating while leaned over. This sidewall stiffness pays off in bike stability while leaned over and exiting a corner hard on the gas.

Michelin’s 2CT puts the harder silica compound in the center for wet grip and wear resistance. Additionally, on Power RS rear tires, the silica layer runs underneath the carbon black to deliver increased sidewall stiffness.

To the stability and grip provided by the construction of the Power RS front tire, Michelin modified the profile to meet its goal of agility. While the profile doesn’t appear different visually, Michelin maintains the tire’s interior profile was changed through tuning the thickness of the tread over the casing. By varying the thickness of the tread, Michelin claims it was able to able to optimize the contact patch at each level of lean to deliver the responsive steering that sport riders prefer.

In Action

Although Michelin gathered five different motorcycle models for riders to sample on the track, I decided to stick to one, the BMW S1000RR, so that my impressions of the Power RS wouldn’t be clouded by playing musical motorcycles. The first couple of sessions on a new track are usually taken at a slightly lower speed while learning the circuit, so Michelin mounted the outgoing tire, the Pilot Power 3, on bikes to give us a quick baseline of what the Power RS was replacing.

As early as the first corner of the second session, where we got our initial sampling of the Power RS, one change was immediately noticeable. Where the Pilot Power 3 tended to fall into corners, the Power RS preferred to be bent in at the entry. This is not to say that the steering was slow. Rather, part of the tire’s agility goal is the precision with which the rider can steer. So, at the entry, the rider, not the front tire profile, determined the line at corner entry.

At the exit of the corner with the throttle twisted to the stop, the Michelin Power RS tires were incredibly stable.

This ease of managing lines carried over to mid-corner, as well. On the track, the need to alter lines is usually necessitated by passing or being passed by other riders. Regardless of the cause, the Power RS tires willingly changed lines, allowing me to precisely dial in the amount of lean desired from the motorcycle.

Stability was another of the stated design goals, and the Power RS rear tire was unflappable as the S1000RR rocketed down Losail’s long front straight with the throttle turned to the stop. As the night wore on, I frequently saw top speeds in the 170-mph range before I popped out from behind the bubble to brake for Turn 1. Here another form of stability was demonstrated. When hard on the front brake, the S1000RR’s line remained rock-steady with nary a waggle of the bar. Although I’m hardly a demon on the brakes, on a couple instances, traffic I encountered in this braking zone caused me to ramp up my braking much quicker than I typically would if left to my own preferred corner entry. In these instances, the Power RS tires remained steady.

The feedback and grip of the Power RS gave me the confidence to comfortably trail brake right to the apex of the tightest corner of the track.

Losail’s Turn 6 is the tightest on the course, and its layout makes it perfect for trail braking to the apex. The feel from the front Power RS, combined with skills that were recently polished at the STAR Motorcycle School, had me comfortably braking while leaned over towards the apex. The same can be said about corner exits. No matter what the lean or exit speed, the Power RS rear tire felt planted – even with the TC light flashing at me corner after corner. (And me chuckling to myself that the Power RSs are street tires.)

You may have noticed that I haven’t said anything about side-to-side transitions. Unfortunately, Losail, with its high-speed flowing layout, doesn’t have any places to test these transitions. Well, the folks at Michelin wanted us to sample the Power RS on bikes at the short end of the displacement range. Conveniently, they shrunk Losail’s layout down to almost gymkhana size and handed us a KTM RC390 to try the version of the RS designed for lightweight bikes. With dust and sand billowing behind the bikes as they circulated the mini-Losail, I decided to trust the tires since I’d only have four laps on this course. While it’s hard to translate steering speed from a 300 to a 1000, I can say that the Power RS tires snapped from one side to the other and stuck like velcro as I flipped from one knee/peg drag to the other – even in dusty conditions that gave me the willies. The tires simply stuck.

On the KTM RC390, the Power RS tires got to show off their steering quickness and willingness to change lines in an instant.

While stability under acceleration doesn’t apply like with the open-class bikes, the Power RS tires responded to brake inputs the same way that they did on the big bikes. One key feature of the RS destined for smaller bikes is that the rear tire is the 2CT structure as opposed to the 2CT+ on the heavier, more powerful machines. The rear tires just didn’t need that technology.

The Checkers

While a few track sessions can’t provide enough information to fully evaluate a new tire, they can give a rider a good impression of what a tire is capable of doing. During my time with the Michelin Power RS on the Losail International Circuit, I had to constantly remind myself that I was riding a street tire – not a dedicated track tire.

The Michelin Power RS tires delivered responsive, predictable steering and superior stability both accelerating to and braking down from the mind-bending speeds enabled by Losail’s long front straight. Given how quickly the tires warmed up on my initial laps on the track, I think that street riders will find that the RSs will stick in the lower-speed environment of the street, and I look forward to sampling the tires on our roads back home. (Now, how can I finagle a set for my personal R6?) Are the Power RS tires the perfect tire? Probably not, but they’re pretty dang good ones that you should sample when you need some fresh rubber for your sporting hardware.

Michelin Power RS tires have been available since January at your local Michelin dealers. Sizes and pricing can be found in the table below.

Michelin Power RS Tire Sizes US MSRP
110/70 ZR 17 M/C 54W Power RS Front TL $184.95
120/60 ZR 17 M/C (55W) Power RS Front TL $186.95
120/70 ZR 17 M/C (58W) Power RS Front TL $188.95
140/70 R 17 M/C 66H Power RS Rear TL $205.95
150/60 ZR 17 M/C (66W) Power RS Rear TL $224.95
160/60 ZR 17 M/C (69W) Power RS Rear TL $232.95
180/55 ZR 17 M/C (73W) Power RS Rear TL $241.95
180/60 ZR 17 M/C (75W) Power RS Rear TL $246.95
190/50 ZR 17 M/C (73W) Power RS Rear TL $282.95
190/55 ZR 17 M/C (75W) Power RS Rear TL $294.95
200/55 ZR 17 M/C (78W) Power RS Rear TL $305.95
240/45 ZR 17 M/C (82W) Power RS Rear TL $316.95