Tires, we all use them but it's remarkable how many people actually know something about tires. Modern tires contain about 30 percent natural rubber, synthetic rubber, oil resin, silica, sulphur and carbon-black, all stuck to a carcass of steel and kevlar.
Tires aren't naturally black, they are grey, but the addition of carbon-black not only makes the tire black, it also slows the aging process.
The silica is abrasive-resistant and gives the tire strength and durability, allowing the use of softer compound rubber for grip. Very soft tires have high silica contents to allow rubber to be super sticky. A touring tire also has a high silica content, but uses a harder compound of rubber to give it extra life.
The information on a new tire also contains a lot of information. If a rear tire is marked 180ZR55/17 it means that the distance from one sidewall through the tire to the other sidewall is 180mm, while the height from the rim to the top of the tire is 55 percent of this distance, in this case 99mm.
The lettering is shows the tire's Z speed rating, which is more than 240km/h, the R signifies it's a radial tire while the following number is the tire's rim diameter of 17 inches.
Then there is a letter and two-digit number, sometimes in brackets. This is the load index, which shows the maximum load the tire can withstand. If it's 73W then this means the tire can withstand up to 270km/h while loaded with 356kg of weight for an hour solid. If this number is in brackets it can withstand more than 270km/h while loaded up for an hour.
Next is the tire's manufacture date in a four digit code. It reads week then year of manufacturer, so 0409 shows a tire made on the fourth week of 2009.
Tires also come with wear indicators, which give a guide as to how much tread-depth is left. Look in the tread for a small section of raised rubber – that's your wear indicator.