Cavi Mike wrote on 10/14/12 at 20:40:47:MMRanch wrote on 10/14/12 at 19:44:52:On our 2011 Dragon Run I passed one of those high-horse-powered sportbikes that didn't want to be passed and then chased his buddy in front of him who tried desperataly to get away but couldn't , all with a BFGoodrich Radial TA. on the back of a 30hp Savage.
Because that was totally the tire and not the skill of the rider. Maybe someone should let MotoGP know those tires they're using are rubbish and they should all switch to car tires! What a revelation!
OK, I'll take a small poke at this one since it gets used by the anti-car tire folks all the time.
Most "track authorized" Motorcycle Race Tires used in America are built by Goodyear Racing Division in Akron, Ohio. Some are marked Goodyear, some are marked Dunlop (old curing molds). These are the tires you see in all those knee dragging, high speed shots on the racetracks here in America.
They use special kevlar fabric carcass construction and the top trade secret tread compounds used are different for the center section than for the two sides and the tri-part compound mix chosen is track specific and temperature specific and wet specific for that particular race.
All the racers in that race are running the same track approved rubber and tire compounds (within 2-3 temperature grades) that they are allowed to pick between because of individual bike needs.Why did this develop?
Tires are such a big part of winning races that some racers on less developed bikes with poorer riding styles were winning races simply because they had better tires. The sport was getting out of kilter, so the ruling bodies said "same tires for everybody" to put the competition back into the race.
Goodyear sends a truck load of bike tires that are pre-produced for that race according to the individual track's history and the season of the year, then the track stewards and the crew chiefs pick "the tire" for the race out of what is in the truck that fits the best for today's race conditions.
Having a bad tire match up is a historical cause for controversy for any given race (and many riders do quote the tires as the reason for their sub par performance that day) but Goodyear has actually gotten pretty good about having the right tires in the truck for that track for that season of the year. And if they fook up a race, they do apologize profusely and bend great efforts to do better next year.
So, your typical motorcycle race tire has NO real relation to any street tire, either motorcycle or car street tire. It is a very different beast with each tire costing at least half as much as your Savage did when you bought it used (assuming you paid a bit for your bike, some of you got such good deals that it wouldn't even buy a singe race tire).
Saying "you can't do that with a car tire" is a bit ridiculous, no you can't do that with a street motorcycle tire either, not at those speeds and grip forces.
You got too many Dragon riders here who have seen Savage car tires do exactly whatever a Savage bike tire can do up on the Dragon runs. You got too many here who have switched back & forth between the two who have first hand knowledge of the handling characteristics of the two.
So, crazy expensive specialized track specific motorcycle racing tires aside, what was your point about handling again?
Source, Oldfeller -- an expert opinion from a 3 year retired Senior Quality Engineer, Goodyear Tire and Rubber Company and currently Dragon car/motorcycle tire switcher outer person (me ).