Rennie Scaysbrook | September 6, 2016
Tires. Those black round things that wrap around your wheels. They are the single most important factor in how your bike accelerates, turns, handles and stops.
Read those last three sentences again.
Good tires are imperative to enabling a motorcycle to do what it’s designed to do. And it’s all the more astounding to me that many riders will look at upgrading almost every other aspect of their bikes before looking at the tires. Yet I can’t blame people for this fault, because, honestly, tires are quite difficult to understand. And something that’s difficult to understand can be scary, so people shy away.
But they need not be. Understanding how tires operate and perform unlocks a world of riding secrets and will dramatically further your ability to decipher what your bike is telling you. It’s a language that takes time to understand, but once you do, a whole new riding experience will open up to you.
At the post WorldSBK Pirelli trackday at Laguna Seca, we spoke to two figureheads at Pirelli and an AMA Superbike legend, all with different experience in the tire game, to try and help you understand the black art.
Piero Misani –– Pirelli Moto R&D and Industrial Director
Italian Piero Misani is one of the biggest players at Pirelli and, as the head of R&D, his is one of the final signatures that goes on a tire’s paperwork before it goes on sale worldwide.
“The first thing we have to say is you don’t have to take care of the tire. That is the most important thing. The rider has to feel comfortable from the very first moment without having to think about it.
“This is made by neutrality in the handling. The other point is the standing up in braking. This especially important for an inexperienced rider, and is critical in a panic situation. We also try to work on the warm up of the tire. On a sunny track day, it’s easy to warm up a tire. But for a common rider, coming from his home on the road, the tire will always be cold. That’s why, for example, with the Rosso 3 we introduced the silica technology, because the silica helps you in the wet but also helps you also in cold conditions.
“This is new for the Rosso 3. Historically, this we showed by the usage of carbon black as the main reinforcement into the tire compound. With the Rosso 3 sportbike tire we have been able totally to get rid of this limitation. You can get the best out of the tire due to the new silica technology, on the road, in cold conditions, and in the wet. But that’s keeping one of the best possible performances of a Pirelli tire which is the capability to be immediately fast and consistent on the track.
“So, this is a general rule: if you have to tell a rider what to feel in the tire, the first things are confidence and the feedback. The tire has somehow to talk to you and be predictable. These things are the most important factors.
“When you test critical conditions, once again the most critical conditions for the motorcycle is the wet. Even though we target for the maximum grip, that’s not enough. If this grip is not supported by these characteristics, which is comfortability and predictability, you will not be informed when you are about to crash. If you are at the limit, unless the tire is predictable and controllable, the grip is nothing. You lose the bike. That’s it.
“So, when you jump on a bike, the first thing you have to notice is how neutral the bike handles, how quickly it moves into a lean. For us, we try and focus on the tire being quick when you’re pulling the bike up and turning in a change of direction. That is a characteristic we are aiming for.
“This reason we have for example spent a lot of time and money starting the contour of the new Rosso III, is exactly for this reason. I would never tell the rider to test the controllability, but you must believe me, it’s there! The stability is key, and this includes high and low speed. In any condition, the tire must be absolutely stable. This is a safety priority.”
Jeff Johnston–– Pirelli Moto Roadrace and Product Manager
Jeff has been a figurehead of Pirelli’s road racing efforts in the U.S. for many years. He’s forgotten more about tires than most will ever know.
“If you’ve come off a worn set of tires,” starts Jeff, “new ones are going to feel like power steering for the motorcycle because your old tires were unresponsive. And of course we’re speaking about a set. If you only replace the rear tire and you had a worn front, then you’re still not going to have the same feeling as a new set of tires, and that’s really important.
“On a new sportbike tire like a Super Corsa SP2 or Rosso 3, you want to ride for about 40 to 100 miles at a very controlled pace, adding lean angle gently as you go through the corners to put a scuff to the rubber. Tires are shiny because the mold is very smooth –– they don’t have mold-release built into them. You have to scuff the tire and break in the edges of the tread grooves. That makes the tire less sensitive to bumps and to pavement irregularities, and that breaks in the tire. When people tell me a tire is slippery it’s because they’re riding on a brand new, unbroken-in tire that steers like power steering and the tread grooves make it sensitive to the pavement irregularities.
“You’re feeling for what the bike is doing and what you’re trying to do as a rider. If you’re unsteady with your throttle inputs you really can’t understand what the tire’s doing because you’re unloading and loading the motorcycle.
“I think a lot of people are scared of front tires and that’s basically a feel thing. You have to feel through your hands, knees, butt, and the balls of your feet. You need to feel what the motorcycle’s doing. One of the best ways to feel for a tire is to do a riding course!”
Jake Zemke –– Former AMA Pro Road Race Champion
A professional racer who battled with and beat the best this country has to offer over nearly two decades, Zemke offers the racer’s opinion.
“When you go out to test tires for someone like me it depends on a few different factors. You’re looking for grip level. You’re looking for longevity, how long that grip stays. Most tires, when they’re brand new right off the warmers, they’ve got really good grip. It doesn’t matter what compound it is. They’re usually pretty good, but you want to see how long that grip lasts before it takes its first little drop in performance. And depending on the tire, some of them will maintain that level, and then you want to see how many laps you get before it might drop again.
“A lot of times when we go out and test tires there’s different constructions and makeups of the tire so maybe the tire flexes a little bit more, a little bit less. Depending on the rider and depending on the situation, the bike, and how much load you’re putting into that front tire, sometimes you’re looking for something that might give you a little bit more stability on the braking. Therefore, if that’s the case, you’ll probably get a bit harder carcass, something that’s going to hold up the load under the braking pressure.
“The grip depends a lot on the age of the asphalt and where they source it from, and temperatures play a huge role in what kind of compound you’re going to use. It’s a little different when you’re just going out for a track day. Those guys are usually looking for something that’s going to get them through at least the whole day. Ultimately everybody wants more grip and they want their tires to last longer. That’s the hardest thing for a manufacturer to find because if you’re going to have more grip it means the compound is going to be softer and it’s going to tear up sooner. So it’s a tricky game these guys have to play to come up with the right balance on the tires.”
Pirelli has also released a short video on the new Rosso III sportbike tire, which can be viewed here.