The type of road bike tire you need depends on the type of riding you do. Are you a competitive racer, a commuter, or a recreational rider? Do you ride on pavement or dirt? How concerned are you about punctures?
Competitive Tires
For racing, you want a light, slick tire that can withstand high air pressure. The high-end fold-up is your best bet. It has a Kevlar or Aramid bead (the edge of the tire that holds it on the rim). Kevlar is a fiber made by Dupont that is very lightweight and very strong for its weight. Aramids, a type of nylon used in bullet-proof vests, is also very light and strong. You also want minimum rolling resistance or friction with the road, so you want a narrow, slick tire. The narrowest tire is 20 c. The "c" stands for millimeters and refers to ETRTO (European Tire and Technical Organization) standards, which most tires today use. Racing tires are very fast but don't last long--about two competitions. They run around $50 or more.
For race training, use slightly wider training tires (23 c) made of a harder rubber compound, but still slick. These last longer, aren't quite as fast, and retail around $40.
High Use Dual-Tread and All-Season Tires
Dual-tread and all-season tires might also be used for training or for shorter recreational rides. These are also fold-ups with Kevlar or Aramid beads. However, they have a dual tread; in other words, the center of the tire is slick like the lightweight racers, but on either side of this center ridge is a stronger tread that makes them last longer and gives them more stability. Width for dual-treads ranges up to 25 c.
Commuter or High-MileageTires
These tires are for people who put a lot of mileage on their bikes, like commuters or long-distance recreational riders. They are made of a generic rubber compound and are heavier, but last longer; manufacturers say 1000-2000 miles, but the actual mileage varies depending on how you ride, your weight, and if the tire is on the front or back. (Back tires wear out faster because of weight and drive force.) These tires have wire beads and so don't fold up--you'll see them hanging on the rack at the bike shop. Width ranges between around 23-32 c. For commuter and recreational riders, the extra weight is not enough to make much difference in your ride. These tires can be dual-tread or slicks, with the dual tread adding stability on dirt or loose surfaces. Prices run around $15-30.
Hybrids
Hybrid bicycles (sometimes called comfort bikes) land somewhere between a road bike and a mountain bike and hybrid tires are also somewhere in between. They have a dual tread, a smoother pattern in the middle to reduce rolling resistance and a rougher pattern on either side of this to add stability on dirt or loose surfaces. In reality, however, bicycle tires on smooth surfaces such as pavement don't need much tread because traction depends on the type of rubber compound and pressure. Bicycles don't hydroplane because of the narrow tire width, curved contact area, cycling speed and high pressure. Rough tread does, however, help traction on dirt or surfaces with loose gravel or sand. Thick tread can also reduce punctures. Width of hybrid tires ranges from 25-40 c. You can put them on your road bike depending on how much clearance you have around your brakes and forks. Check with your bike shop about this. These tires range around $15-30.
Where to Buy Tires
Probably the best place to buy tires is a bicycle shop because of the wide selection of tires and employee knowledge. There are also several on-line outlets that offer excellent selection and great sales. Avoid discount stores; they have very limited selection and employee knowledge.
