Lenny, you've got me worried now, man! I was planning to try some Dunlop GPA-Pro's (the AMA spec tire) this year. I've been running Pirellis. I watched that video and it sure didn't look to me that those tires should have been that cold. Your entry speed and lean angle were probably the highest there of any previous part of the video, but it didn't look unreasonable I unfortunately couldn't make it to Barber this year - had a great time last year. But now I'm a little concerned about the Dunlops. How cold were the track and ambient temps?
100% agree Vin!I wouldn't be overly concerned about using Dunlops, they do require heat. I've done the same thing Lenny did on Dunlops more than once (not intentional) but I still run them. One thing to remember is they do not work well in colder/lower temp because the carcass is much stiffer. They need heat and once you get them up to temp they work pretty good. I've tried Pirelli's for the first time in 5 years last time I rode and said I'm switching to Pirelli's next season. Like Lenny said you're going to have to change your riding style when the temps drop, but that goes for any tire. Crashing is a part of our sport especially when you start pushing, that's also goes for any tire.
Thanks AJ! Could Jen Make some Chocolate Chip cookies with that? LOL!I know what I am getting Lenny for X-Mas this year...a pair of Mechanix gloves and a allen socket and ratchet set. Protect those hands my friend! ;-)
But I really don't have a feel for the tradeoff in temperature/traction at middling temperature between 50-70 degrees. Is traction off by a few percent at 50 degrees, say, or is half the traction gone? Anybody seen any pretty temp/friction coefficient charts that explain how much the grip falls off as it gets colder for various tires?
Menotomy, watched through that video a few times...it sounded like you were picking up the throttle right before it slipped, before reducing lean angle; was it the rear tire that went out? You could see the turn exit so I can see why you'd accelerate there but maybe just a little too much for the lean angle? Or is my analysis all wrong? It's hard to tell in real time what's going on. Everything is fine and then you're sliding.
I thought the sliding scale started at 100.00000000001That's a question that comes up a lot at YCRS when they talk about the 100 points of grip for a tire. Unfortunately, it's literally impossible to chart it, because there are so many variables it'd never happen. The 100 points of grip is a sliding scale. In Lenny's case, his luke warm tire has a 100 points of grip. And that same exact tire, on the same turn, in the middle of July on a sunny day while he's out there riding in A group, will still have 100 points of grip. But it will be operating at temperatures it was designed for, so it's 100 points of grip will be at a higher threshold than this past weekend.
I both do and don't like the 100 points of grip paradigm. It's important to illustrate the trade off between lean angle and braking/acceleration is always the same. I get it. It's absolutely not helpful in telling you how to know when you've reached the full 100 points other than "because then you crash." Crashing is a painful and expensive teacher, so how does one acquire the "feel" for when you're on the edge of traction? Supposedly the tires make noise to tell you, but over the engine and wind, I certainly couldn't hear anything in time to adjust from the video.
I both do and don't like the 100 points of grip paradigm. It's important to illustrate the trade off between lean angle and braking/acceleration is always the same. I get it. It's absolutely not helpful in telling you how to know when you've reached the full 100 points other than "because then you crash." Crashing is a painful and expensive teacher, so how does one acquire the "feel" for when you're on the edge of traction? Supposedly the tires make noise to tell you, but over the engine and wind, I certainly couldn't hear anything in time to adjust from the video.