Cycling Tires

Road bike tires typically have a large diameter, a smooth tread pattern, and narrower widths than off road tires. Just like car tires, they use a series of numbers and letters to identify the size. On the side of the tire will be a number like this "700x23c". The "700" refers to the diameter of the tire; the "23" refers to the width of the tire; and the "c" designates which 700 rim it uses, there are other letters such as the "700D" tires, 650c and 650B rims. Fractional sizes like "27x1" will not fit the same rim size and slick tires marked "26x1.0" are usually mountain bike tires. 

Road Tire widths are measured in millimeters. Wide tires are usually used for practice and training and should be kept at the lowest pressure possible for maximum grip. Wide tires are typically over 25mm wide and weigh slightly more. Because wide tires can be run at lower pressure, they provide a larger contact surface to the road. These are probably the most popular road tires because of their forgiveness on bumpy roads and protection of the rims. When choosing a wide tire, be sure that the tire will not rub the bike frame or the brake caliper.

Narrow tires are used for road riding, easy trails and any roads where high speeds are warranted. Basically smooth or slick tires roll the fastest. These tires usually weigh less and can be run at higher pressure, up to 160psi on some models. 23mm is the most popular size for training and racing.

TPI stands for the number of threads per inch in the casing of the tire. Racing tires will have a high TPI, typically over 100. In addition to having a high TPI count, racing tires have a thinner sidewall, and usually weigh less. These tires are also more puncture resistant, but also usually cost more.

Tires with a low thread count are less expensive and use for training and long distances. These tires are thicker so subsequently they are more resistant to puncture. Tires with less than 100 TPI are considered low thread count tires.

The bead is the edge of the tire casing that contacts the rim. There are two types of beads that you will encounter. Kevlar beads (also called folding beads) are usually the more expensive, but they keep the weight of the tire down and also make it possible to fold the tire for storage. Tires with Kevlar beads are harder to mount. Kevlar beads are used on racing tires where weight is and issue.

The other type is a wire bead. Wire bead tires are heavier, not foldable, easier to mount, and less expensive. Wire bead are not usually available on tires with a high TPI. These tires are best for training and where price is an issue.

Carbon black compounds are used in tires when durability is very important and the different tire manufacturers have each developed their own carbon compound formulation that they fell makes one tire better than another. Carbon black compounds usually do not wear out as quickly as other synthetic tire compounds and they are more forgiving of improper care and storage.

Other synthetic Compounds, like silica, can be engineered to meet any tire specification needed. These are typically designed for high performance and not usually for training tires.

Multi compound tires give the best combination of a firm hard tire, but the gripping ability (stickiness) of a soft tire. This is accomplished by using a harder tire compound in the center area and a softer better gripping substance on the sides. The softer sides make it possible to take turns at high speeds and not have the bike slide out from under the rider. As you might expect, these are the most expensive tire option.

Take some time and seriously evaluate how you will be using your tires most of the time. It is not unusual to have multiple sets of tires for different condition.