# A Guide to Motorcycle Tires Sizes

Determining which motorcycle tires to use on your vehicle is one of the most important parts of the process of selecting and modifying your vehicle. Putting the correct size and type of motorcycle tires on your vehicle will improve its overall gas mileage, performance, top speed, handling and more, and will extend the overall life of the vehicle and the tires as well. Picking out which tires are best for your bike can be difficult though, as there are three different types of sizing systems; Alphanumeric, Inch, and Metric systems. Read on for a brief overview of all three of these systems.

Alphanumeric System

The alphanumeric system for classifying different motorcycle tires is based upon both numbers and letters. Generally, the numbers refer to the size of the motorcycle or the specific brand, while the numbers specify the exact size. The format of a tire size in the alphanumeric system is typically @@-## *, where @ represents the letter and the type of motorcycle, # represents the tire size, and * represents the rim size.

Inch System

The inch system for classifying tires is relatively straightforward. It is either set up as a set of numbers followed by a dash and then another set of numbers, or as #/%/@, where the first # is the size of the tires in inches, the % is a letter classifying the series of tire, and @ is the size of the rims for those tires. The different series of tires are typically either S, which refers to tires that are rated to go up to 112 miles per hour, H, which refers to tires that are rated to go up to 130 miles per hour, or V, which refers to tires that are rated to go up to speeds of 150 miles per hour, or sometimes higher in certain cases.

Metric System

The metric system also makes use of ther S, H and V symbols in order to classify the series of tire and the top speed that is available. Otherwise, it's very much like the inch system, except that the measurements for the tires are given in centimeters instead of inches. In order to convert from a centimeter reading to an inch reading, divide the centimeter value by 2.54. Metric system readings for different tire sizes are usually found in Europe and other parts of the world where they use the metric system, such as Asia and Canada.

Converting Between Systems

While it's relatively easy to convert between the inch and the metric systems, the alphanumeric system is a bit trickier. Most motorcycle tire shops have a conversion chart that you can use to determine whether or not a certain set of tires will work for your vehicle. You can also find the charts available online as well, for your own records.

For more information about motorcycle tires, consult with a professional at an auto body repair shop or speak with a motorcycle expert.