All About Motorcycle Tires


Tips, Tricks and Techniques for July 2014 By Diane Ortiz – President and founder of the Big Apple Motorcycle School.

Motorcyclists depend on their tires to maintain stability, traction, and to literally, stay alive. Underinflated tires are often overlooked and remain a major factor in tire failure and crashes. When the ground is cold or wet, tires provide the traction needed for accelerating, braking and turning.

 

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Motorcyclists depend on their tires to maintain stability, traction, and to literally, stay alive. Underinflated tires are often overlooked and remain a major factor in tire failure and crashes. When the ground is cold or wet, tires provide the traction needed for accelerating, braking and turning.

 

It’s important to choose a tire that is the right size, including height and width. Here are some tips about what all those numbers and letters mean so that you can compare different tires for your ride:

 

Tires sizes can be specified in either Metric (180/55ZR-17), Alphanumeric (MT80S-16), Standard inch (3.25H-19) or Low profile inch (4.25/85H-16). The first number in all but the alpha system represents the nominal tire width (in either millimeters like 180 or inches like 3.25). In the alpha system, the letter after the M indicates the tire width. For example, the MT80S-16 uses the T as the width indicator corresponding to 5.0 inches.

 

The second part (if it exists) indicates the aspect ratio of the tire – the ratio of height to width. The smaller this number is, the lower the profile of the tire. For example, the 180/55 indicates a 180mm width and 55 percent aspect ratio, yielding approximately a 99mm height.

 

The third portion is the speed rating of the tire; the maximum speed the tire may be run with maximum load at its maximum pressure rating (information found on the sidewall of the tire). The speed ratings are letters. For example, the 180/55ZR-17 tire has a Z speed rating that translates to “above 149 mph.” The last designator is the rim diameter. That same tire is for use on a 17-inch rim.

 

Tires marketed as “touring” or “sport-touring” may have a longer expected mileage than those described as “sport” or “track” tires. The more performance-oriented sport tires will give up some mileage to provide better overall grip. Track tires might also give up wet grip for pure traction under dry conditions. Racers often run slicks (tires with no rain grooves and are not street legal) for additional adhesion. Touring riders may not be as concerned with pure dry grip but might want a smooth running tire with long life and good traction under rainy conditions.

 

Most motorcycle tires today are tubeless, meaning the tire doesn’t have an inner tube to retain air. Most tires with spoke wheels require tubes. However, some newer design spoke wheels have the spokes attached to the outside of the wheel and can retain air without a tube. In general, tubeless tires are considered safer as loss of air pressure is normally not as sudden as a puncture in a tube, which could cause instability and lead to a crash. Many motorcycle tires are also radial construction but some are bias-ply. Don’t mix radial and bias-ply tires! Check your owner’s manual for information about the type of tire that was supplied as original equipment.

 

Never wait until the tires are bald before changing them. Tires are the most important element of your bike – keep them in good condition and properly inflated so that you can get the most out of your riding and stay safe!