Monday, August 7, 2017

Comfort Zone

Me, CBR600RR with full rain tires, Woodcote corner, Silverstone.
























I have ridden on racetracks for 22 years and always managed to avoid riding in the wet. Recently, I had a choice: Ride the Silverstone Racing Circuit in the wet, or don't ride it at all. I chose the wet. I am happy I did, because I was able to watch the MotoGP round at Brno with entirely new eyes, an immense amount of respect for those who can go fast in the wet, and more than a little sympathy for Valentino Rossi.

Through chance and happenstance, I had my choice of two machines at Silverstone. For the first session - wet but not pouring - I chose the 2017 Yamaha YZF-R6. It was fitted with Pirelli Supercorsa tires - dry-weather DOT-certified racing rubber, with just enough grooves to make it legal for road use. The bike also comes stock with an immensely powerful system of electronic rider aids. I set the thing on full nanny mode - Power Mode B, Traction Control 4 - and headed out.

Even with those settings, the bike was - tricky. I could get it to twitch in a straight line, and there was no way to get any kind of confidence in the grip. I felt as though I was playing a video game, with virtually no feedback from the machine, and just spent the session blasting from corner to corner as rapidly as I could, then creeping around them at a snail's pace. That's not true. I think I saw a snail pass me once. And it gave me the finger.

Next session, track soaking and rain lashing down, I got on the Honda CBR600RR. A wonderful bike, yet a pale shadow of a new-generation R6. Cruder, slower, and no electronics at all. But it was mounted with full rain tires.

The difference in feel was - what is the term for the distance from zero to one? There was grip. I wasn't at dry condition lean angles by any stretch of the imagination. But I was able to brake ridiculously hard and to start feeding in the throttle far, far earlier than I would have imagined. I was able to drift the bike sideways over the painted grid lines exiting Woodcote, with a much greater level of confidence than I'd anticipated. For those conditions, the simple change of rubber made the greatest amount of difference, compensating for everything the CBR600RR lacked.

Dry pavement, dry-weather tires, all is right in the universe.

The track dried for the last session. I went back out on the R6, and I was immediately knee-down everywhere, confirming the positive dry-pavement performance of the Supercorsas. I left the track that day with a new, personal, visceral respect for the difference between rains and dry weather tires.

Arguments over whether Rossi waited too late to switch to the dry motorcycle at Brno aside, I can understand and feel why he made the choices he made. Rossi was leading the race, was faster, and the difference in the feeling between slicks and wets on a damp track is massive. Non-racers really don't grasp how tricky slicks can be to get to function - they're just tires, right? Hardly. At this level, they are insanely sensitive performance devices, rubber that will give you grip that your brain almost cannot process, yet will spit you off the machine if you go into a corner with the temperature of the tire just a few degrees out of its optimal operating range. A full-on racing slick (or DOT race tire) out of its operating temperature range is just flat spooky to ride on, even on a dry surface.

Part of the magic of Marc Marquez is that he's able to ride rapidly in those conditions, when the grip simply isn't there, sliding the machine around until the tires come up to temperature and the conditions improve.

Rossi? I understand why he clung to the rains for one more lap. The difference in feel, the confidence that a racer craves. The rains were giving him exactly what he wanted - reassurance and speed. And he knew what that out lap was going to feel like on the slicks. It was going to be the exact opposite. No racer wants that.

I can't empathize with the choice made by Rossi. All of the riders in MotoGP are professionals, I'm a hobbyist. And every one of them is so far beyond my level of capability that it's like they are governed by a different physics textbook than I am. 

But I can sympathize.

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