Tire Speed Rating For On and Off-Road Motorcycles
Each tire for an on or off-road motorcycle has a tire rating — or the maximum speed at which it can perform for a significant span of time. Regulators classify tires according to this rating, which helps determine the types of vehicles that can use them.
For example, a sports car would likely use tires with a higher tire rating — as drivers purchasing these cars want to go fast. Large machinery tires for machinery such as combines or tractors would have a lower-rated tire, as they are needed to haul heavy loads at a slow pace.
The tire speed rating is engraved on each tire’s sidewall along with other important specifications. Ratings are expressed as one or two letters that correspond to a mileage capacity.
You can find the mileage capacity on a tire speed rating chart like this:
You will notice that as you increase in the alphabet, the maximum speed also increases. The exception to this rule is the “H” rating of 130 mph. Due to changes in the rating system over the years, “H” maintained its position in this spot despite other numbers shifting around it.
Tires with higher tire speed ratings typically handle heat better. This is because the increased rotations and subsequent friction that the tires generate heats up the rubber. As such, these tires need to be able to remain cool so the vehicle can continue moving.
It is also important to understand that these ratings act as an overall guideline. Tires are tested within a lab environment, so the manufacturers will not be able to determine exactly how they will perform on each type of terrain.
To determine the speed rating, on or off-road tires are mounted to a wheel and connected to a testing machine. Then, pressure is applied to the tire. The tire begins rotating at a slow speed for several minutes, increasing through the ratings over time. Manufacturers will look for signs of distress, making sure that the tire is capable of withstanding each progressive rating until it reaches its maximum speed.
Drivers are responsible for using the tire speed rating and other factors like terrain, weather, and load weight to decide how fast they should drive. Most cruiser motorcycles will have an H rating, and most sportbikes will have a “ZR” rating. Remember, this rating speaks only to the tire’s capacity — not the vehicle’s capacity.
In order for tires to reach higher speeds, they often need to be made from softer rubber. At the same time, these tires have a rigid build that allows them to graze over any road hazards at high speeds. This creates a rougher handling experience, but most sport car drivers do not mind trading off speed for a bumpier ride. These tires typically wear out faster, given the type of driving that they do. If you want to purchase W or Y-rated tires for high-speed driving, just anticipate that you will have to change them earlier.
Choosing the correct tire speed rating depends on several factors, most importantly the type of vehicle you drive. Here are some basic guidelines:
- Adventure/Dual Sport motorcycles: Q, R, S, T
- Cruiser/Touring: H
- Sport: W, Y, or ZR
When replacing tires, you should choose ones that match. You should not upgrade to higher-rated tires if you plan on keeping any of the lower-rated ones. Especially when considering the differences between front and rear tires, the balance is important to maintain.
In the case that you have tires with different speed ratings, you should always follow the lower rating. Never expect the lower-rated tires to perform at the same level as the others.
Practical Use of Tire Speed Rating for On and Off-Road Motorcycles
While you should understand the tire speed rating, you should make driving decisions based on other factors, as well. If you have tires that are under or over-inflated, punctured, patched, or plugged; you should not treat them like you would a brand-new set.
Although your tire speed rating may tell you that you can drive over 100 miles per hour, if you are carrying a large load, you should reduce your speed and take caution. Make sure to have regular maintenance checks for proper inflation and alignment. Follow local speed limits to avoid accidents and have both the suspension and brakes checked often.
Tire speed ratings are based on a theoretical understanding of real-life situations and factors. They are considered guidelines for vehicle use, but they ultimately cannot predict or account for all variables that affect performance.
Contact Dunlop Motorcycles Tires today if you have any questions about tire speed rating or motorcycle tires. Our experienced team will be happy to help you choose the best tires for your bike.