try out some of this info
“When it comes to sport bikes, the subject of tires is a common topic of discussion, and few topics evoke as much passion or controversy. What is the best tire? How old of a tire should you run? When is a tire worn out? How many heat cycles will a tire last? Where is the best place to purchase replacements? What is the best tire pressure? Etc., etc., etc. The answer to every one of these questions is the same; it depends. Depends on your riding style, where, when, and how frequently you ride. However, there are some guiding basics that will help you make the best decision. One thing to remember is that tire technology is moving extremely fast. The greatest performance tire of all time from a few years ago can't even compare to today's sport-touring tires.
What is the best tire? First we need to realize that all tires are a compromise; primarily, a compromise between mileage, wear, slow-speed handling and high-speed handling. The answer to this question is also extremely suggestive and depends a lot on you. While the Dunlop or Michelins race-bred tire may be the most popular, that doesn't necessarily make it the best tire for you and your riding style. Different tires and tire brands have different characteristics. For example, Dunlop's tend to have stiff sidewalls and pointy profiles, while Metzelers lean towards very soft sidewalls and very round profiles. And this can change from one tire make to another and from tire models. Well, which is better? Again, that depends on you… So how old of a tire should you use? The answer for this is easy. It depends! If you need to get the most out of your tires, then the fresher the better. If you like a tire to last longer, then the age of the tire is less critical. But you should never buy or use a tire that is more than six to seven years old. But how do you know how old your tire is? Carbon dating? Serial number cross-reference with manufacturers? Actually, your tire has the date of manufacture, or the "born on" date. How nice! If you look closely you will find a three or four-digit number stamped into the sidewall of your tire. It will read something like 449 or 2101. What do these numbers mean? Well, a 449 means the tire was manufactured during the 44th week of 1999. 2101 means the tire was manufactured the 21st week of 2001. Years prior to 2000 have a one-digit number to reflect the year, and after 2000, a two-digit number is used. This is a simple and easy way to figure out the age of a tire.
But why is a fresher tire better? Well, first, rubber is organic and it decomposes. Second, after your tire is manufactured, it may sit on the top shelf of a scalding hot warehouse for four years, outgassing all the while. Then it goes to the local shop, where it sits in a south-facing window (outgassing every time the sun sets for another year before you finally buy it). So, you end up with a five-year-old tire that may already be worn out before you've ridden home. Then you'll complain every time the tire slides around underneath you. Not because it is a bad tire, but because it has gotten so old and outgassed so much it has become brittle. If your primary concern is a tire that lasts lots of miles, an older tire will do fine because it has gotten hard with age. But again, rubber is an organic material, and a tire that is seven years old is not as capable as the exact tire that is newer (
http://www.canyonchasers.net/shop/generic/tires.php).”
A couple of other sites with more info for ya
http://www.rattlebars.com/valkfaq/tirewear/
http://www.totalmotorcycle.com/photos/tire-tyre-guide/Tire-TyreTech.htm
