| Author | Message | ||
     Sslowmo |
Has anybody used the Power Race tire's on the xb12r? I am wondering a few things. First, how much grip do they have cold? I don't have tire warmers. How long do they take to get some heat in them. I don't Ride at race pace but I can get a knee down on the Buell. What should I expect the handling to be like.What tire pressure is the best for track day. Any info would be great. also, I have the med/soft front and the Pr3 soft rear. Thanks, Aaron | ||
| Schmitty |
I race CCS on Michelin Power Race tires. I would strongly recommend tire warmers! If you can't swing for them, be sure to give yourself a couple laps to warm the tires before you really push hard. Once they are warm though, the grip seems endless. The COLD tire pressures are 31psi front and 28psi rear. Again that's COLD pressure. And those numbers come directly from the Michelin tire guy at the track. They have proved to be very durable. If you have any other questions let me know. Schmitty | ||
| Sslowmo |
I have only run Dunlop Qualifiers on the track. I was also wondering how is the grip on the power race tires right out of the gate, cold? Are they like a street tire cold, that if you keep it smooth for a few miles (laps) you can then hammer it? Or are they slicker cold and take longer to heat up. Or maybe, they have better grip then a street tire cold? Also, as for pressure for the rear I hear it is 22-24 psi. I think I will have too play with that. But 31 psi for the front works for me. Thank's, Aaron | ||
| Oxygen151 |
Just out of curiosity, why do you race guys run so much lower tire pressures in the back than the front? Traction?? Overall your tire pressures are a few psi in the front below what Buell uses as a starting point of 36 in the front, 38 in the back. I am just curious as to why this is? | ||
| Juniorkirk |
well, if you think about it, the back tire is put under a lot more stress than that front one so it will get hotter, which will increase the PSI more than front that doesnt get as hot as the back tire. That's what i would think, correct me if im wrong though. (Message edited by juniorkirk on March 30, 2009) | ||
| Schmitty |
Heat is part of it. The tires are warmed to 175-180 degrees with the tire warmers before the race even starts. This is significantly hotter that your tires would ever get on the street. It also has something to do with the tire carcass. The lower pressure allows the sidewall of the rear to roll around the bead somewhat to allow for a larger contact patch. Actually for some people the front tire is under more stress than the rear. Depending on how hard you charge in on the brakes, and whether or not you trail brake to the apex, the front can take a pretty good beating. The higher HP liter bikes put more stress into a rear tire than our XB's do. Schmitty | ||
| Rocketsprink |
31 front, 22 rear. are these for track days only, or are you running them on the street also? That I would not recommend, as they won't last very long. I've been running them on my race bikes since 2005 and they are great tires....for the track. Without warmers, allow a few laps to get heat into them, as stated above. | ||
| Rocketsprink |
THIS INFO MAY HELP SOME......What is the best tire compound? It depends . . . on how you ride. Many people believe that a race compound tire is stickier and allows them to ride faster and with more confidence. This might be true for those of you who ride on the track, but not everything that works on the track works on the street. Before we get into the hows and whys, understand how a tire works. When a tire is heated, the rubber becomes more pliable, allowing the tire to ooze into all the nooks and crannies of the surface you are riding on. However, as the tire heats and cools, it goes through a process called outgassing . Literally, parts of the tire are turned into gasses and escape, resulting in the changing of the chemical makeup of the tire. The results of outgassing cause the tire to become brittle or less pliable, hindering the tire's ability to conform to the road surface. Back in the day of flat-track racing, it was a common practice to take tires and throw them up onto a flat, southern California roof for a few weeks to bake in the sun, periodically flipping them from side to side like a pancake. The tires would heat and cool and consequently outgass until they were rock hard. Perfect for flat-track racing. So, now back to our race compound tire. The race tire is designed for the racetrack, hence the name and usually the red sticker or other marking on the sidewall of the tire. They are designed to be used two or three times before they are discarded. Even "DOT Race" tires are typically only good for two or three days of use. That equates to two or three heat cycles and two or three periods of outgassing before the chemical balance of the tire has changed so much that it is no longer the same tire. Also, race tires are designed to be able to carry more heat before the tire melts. This is to handle the extreme speeds, cornering velocities and higher abrasion characteristics of a race track. This means it also takes more time and more aggressive riding to get the tire to its optimum operating temperature. Race tires are awesome for the track rider. They allow the racer to get the most out of the tire, but at a cost (they don't last as long). The street rider who uses race compound tires is simply wasting their money and taking unnecessary risks. Even the fastest street rider is probably not (and should not) be able to get the tire up to its optimum temperature to reap the benefits of the added traction. Street riders are forced to stop for stoplights, police officers and traffic in general. They are also a full-on idiot if they ride at 100-percent ability, as fast as they can, in a street environment. However, the race tire is still outgassing at the same rate it would if it were being used on the racetrack even though the tire will never reach operating temperature, and never achieve optimum levels of cohesion. Street riders will, however, get a greater level of traction and more life out of a street tire that is designed to withstand hundreds of heat cycles and operate at a lower temperature. And in fact, most modern "sport-touring" tires will provide a better level of grip for 90% of all street riders than sportier counterparts. Only an elite few, and they are probably not reading this anyway, can use the full potential of a Michelin Pilot Power or Dunlop Qualifier. In fact, its quite amazing what skilled riders can do on modern sport-touring tires like the Michelin Pilot Road or Continetal Road Attacks - skilled riders can still drag knees around corners with these supposedly "hard" tires. Some street riders feel that it is an advantage to buy "take-offs" from racers. Take-offs are the race compound tires (sometimes race slicks) a racer has used up. Rather than discard the tire, they sell them to street riders. Take-offs do a great job of impressing your friends by allowing them to assume you were able to thrash the outside edges of your tire with your amazing riding ability. But the reality is you may be riding on a tire that has plenty or tread left but is actually worn out or has very little grip left in it. The moral of this story is not to be so afraid of riding on tires designed to last a bit longer. Honestly evaluate the type of riding you do and make your decision based on that information. If you mostly drone up and down the interstate on your way to work with an occasional weekend jaunt up the canyon, you probably don't need as much tire as the rider does lots of high-speed track days, and has never worn out the center of a tire. Most of us will never be able to over-ride a modern "sport-touring" tire during very spirited street riding unless we are using incorrect riding form and style. I have seen all of these touring-based tires on racetracks and on colder track days, the touring tires came up to temperature quicker and provided MORE grip than the race tires. So much so, that after a track session, the race tires were, literally, cold to the touch, while the touring tires were nice and warm. Plus, you get the huge benefit of not having to change tires more frequently than you change your oil. But whatever you do, do not mix and match tires, particularly tires of differenc construction (radial vs. bias) and even tires of the same construction from two different manufacturers. You never know what handling result you will end up. We realize that sometimes you have to do what you have to do, and when out on the road getting a flat tire means you run whatever tire you can find. So at the very least, avoid at all costs putting on a stickier/grippier rear tire than the front tire. To do otherwise and you could easily find yourself in a situation where the traction of the rear tire overwhelms the traction of the front tire. |
