Note the visible tread patterns...
Note the visible tread patterns in dot approved race tires. Amazing levels of grip and lean are achieved despite the tires' street legal construction.
Race Rubber
While many race classes use DOT road legal tires, the premier classes, like MotoGP and Superbike use non-road legal race tires. This means slick, treadless tires in the dry, very heavily treaded wet tires for use when it's raining, and intermediates for damp conditions.
Slicks offer the ultimate grip. Since they have no tread, there is even more rubber in the contact patch. The lack of tread blocks means the tire flexes less in the tread area, thus creating less heat, and allowing a softer compound to be safely used.
Conversely, wets have lots of small tread blocks and deep tread cuts. These perform two functions: they allow lots of water to be cleared away from the contact patch quickly, and they also increase flex in the tread area, meaning wets get very warm very quickly. Indeed, if a wet tire is used in the dry, the lack of water cooling means it quickly overheats, degrades, and starts to break up.
Intermediate tires, as the name suggests, are a halfway house. They can simply be a slick tire with a small amount of grooves hand cut to increase water dispersion and make the tire run warmer.
Running wets and slicks on the road sounds like a good idea. Who doesn't want more grip? But in reality, it's a bad plan. Track tires are designed to be used in track conditions-constantly accelerating, braking and turning hard. Slicks shed heat very quickly, so keeping them at operating temperature on the road is almost impossible. And their carcass is designed for use over a short period in controlled conditions. They're not meant to do a thousand miles on freeways, city streets and back roads, or be used for two-up touring trips, and trying to do that can be dangerous. In short, when road legal sport tires are as good as they are today, it's simply dumb to use track rubber on the road.
Punctures
No matter how good tires get they'll stop working if you stick a hole in them. A puncture is one of the few breakdowns you'll still get on a bike today, and while they're rare, it's worth knowing how to deal with them. You can get small puncture repair kits that will easily fit under the seat of your bike or into a rucksack pocket, and come complete with small gas cylinders that can re-inflate the tire once you've fixed the puncture.
The kits vary so check the instructions. But essentially, they include some rubber cement, self-vulcanizing plugs and an installation tool. Simply find the hole, remove any debris still in there, and clean it out with the rasp section of the tool. Cover the plug in cement, and push it into the hole. Trim off the excess plug, and use the gas cylinders to inflate the tire. Some kits don't seem to have enough gas to fully inflate a fat rear tire, so you might want to add a few extra cylinders.
The other option is a can of Fix-a-flat. These are super-convenient aerosols with a rubberized cement mousse inside. You connect it to the tire valve, and the pressurized mousse inflates the tire and seals the hole. While these are easy to use, the repair is much more temporary and only suitable for getting you home at reduced speed.
Neither of these roadside fixes are permanent though-you need to change the tire!
Reading A Tire: 180/55 ZR 17 98W
The numbers on the sidewall of your tire may look arcane at first, but are actually pretty straightforward. The first number-normally a 120 front and a 180 or 190 rear-is the width of the tire in millimeters. The second number after the slash (normally a /70 up front and a /55 or /50 on the back) is the aspect ratio of the tire. Basically, it's how tall the crown of the tire is as a proportion of the width. So a 120/70 tire is 120mm wide and (70 percent of 120) 84mm tall. These numbers are all nominal, and can vary from model to model. So you might find that a 190/50 rear tire from one manufacturer is hardly any wider than a 180/55 from another.
* The two letters next are the speed rating of the tire. Most sportbike rubber is rated to at least `Z', which is over 150mph. If that is followed by an `R' then the tire is a radial construction.
* The next number is the diameter of the wheel the tire is designed for, in inches. Nobody seems very sure why we use a combination of metric and American units for tire sizes--we just do.
* The final numbers are load indexes, and tell you how much weight the tire is designed to handle. Make sure you stick withtires that have a load index suitable for your bike.
* The sidewall will also say if the tire is a front or rear fitment (you don't want to mix these up), whether the tire is tubeless or a tube-type and an arrow showing which direction the tire must rotate