Checking Harley Tire Pressure and Inspecting Tread

Although modern motorcycle tires are manufactured to very high performance and durability standards, taking them for granted can be a dyer mistake. Motorcycle tires are not all alike and certainly much different than the tires on our cars. The tires on your motorcycle are absolutely critical to your safety and long-term enjoyment of your motorcycle.

Here are some important motorcycle tire facts and safety tips to consider. Tires that appear to be the same can be very different in terms of how they are designed to be used safely. One of the key factors is the speed rating. This is the letter (alphabetical) code number at the end of the tire size code imprinted on the sidewall of the tire, for example: in the code 120/90B-19 60 H, the “H” represents the maximum safe speed rating is 130 mph.

Here is a table of the speed ratings:

Code Max. speed (mph) / (km/h)

L 75mph / 120kmh
M 81/130
N 87/140
P 93/150
Q 99/160
R 106/170
S 112/180
T 118/190
U 124/200
H 130/210
V 149/240
W 168/270
Y 186/300
Z >149/>240

The majority of motorcycle tire sizes are labeled in metric dimensions. Those dimensions and other information must be molded right into the sidewall of the tire. Using the same example, 120/90B-19 60 H, here’s what the dimensions mean:

“120” is the section width or the overall width of the tire in mm when installed on the rim and ready to ride.

“90” is the aspect ratio, which is the sidewall height from the tread to the bead of the tire as a percentage of the section width. In this case, it is 90 percent of 120 mm or 108 mm.

“B” indicates that the tire is of bias-ply construction; an “R” indicates it is a radial.

“19” is the rim size diameter in inches.

There is also a code for the safe maximum load called the “load index.” In this example,“60” is the load index rating code, meaning the maximum load rating code means 551 pounds. The load index chart goes from 33 (254 lb rating) to 83 (1074 lb rating).

Each motorcycle is designed with specific chassis specifications and suspension components that are intended to maximize handling, braking and stability with a specific type of tire in mind. Changing from bias ply to radial tires or vice-versa may adversely affect the handling of the bike, never make that type of change without consulting a professional 1st. Going with wider tires to try to increase cornering performance, for example, may cause interference between the tire and suspension or driveline components.

Staying with the same type, style and size tire that was specified as original equipment (OE) for your bike is the best way to assure consistent performance and longevity. For example. A lot of Harley owners like to try fitting the widest tire possible on the back of their bikes. Going with a wider tire may cause interference between the tire and suspension or driveline components.

Whatever you ride and wherever you ride, your Harley tire pressure and tread life are the most critical safety item on your motorcycle. Take good care of them and inspect your motorcycle tires before every ride.

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