Motorcycle Tire School

Getting the most from your motorcycle tires requires proper care and maintenance. Get the most up-to-date information in this section.

Contents:

Tire Safety and Care

Tire Inflation

Always keep the motorcycle manufacturer's recommended air pressure in both tires. This is an important requirement for tire safety and mileage. Your motorcycle owner’s manual will tell you the recommended cold inflation pressure. On some motorcycles, the recommended front and rear tire pressures will be different. The pressures stamped on the sidewall of the tire are only for maximum loads. On some occasions, these pressures will also be the manufacturer’s recommended settings as well.

Riding on tires with too little air pressure is dangerous. The tires will build excessive heat. This can cause a sudden tire failure. Under inflation may also:

  • Damage the tire, leading to tire failure
  • Adversely affect vehicle cornering
  • Reduce tire life
  • Increase fuel consumption
  • Cause fatigue cracking

Riding on tires with too much air can be dangerous. The tires are more likely to be cut, punctured, or broken by sudden impact. Do not exceed the pressure indicated on the tire sidewall. Consult your owner’s manual for the recommended inflation and other tire information.

Never inflate a tire unless it is secured to the motorcycle or a tire-mounting machine. Inflating an unsecured tire is dangerous. If it bursts, it could be hurled into the air with explosive force.

Valve Stems, Cores & Caps

Old or damaged valve stems and cores may cause air loss. Replace them when mounting new tires. Use caps (finger tight) on the valve stems to keep dust, dirt, and moisture away from the valve.

Tubes

When fitting a new tire on a rim requiring a tube, a new tube should be fitted at the same time. Old tubes become stretched, and if an old tube is fitted within a new tire, it can crease and fail due to thinning of the tube rubber. Tubes should be repaired only by an expert. Secure tube valve assembly to rim with care. Inspect rim band, and consult motorcycle dealer for correct rim band replacement.

Always check the size markings on the tube to ensure that the tire size appears on the tube. Do not fit tubes in radial motorcycle tires, nor fit radials on rims requiring tubes, unless the tubes bear matching size and radial (R) markings.

Keep in mind that hard cornering, passengers, heavy loads, and sustained high speeds will require higher pressures (up to that indicated on the sidewall).

Matching Front and Rear Tires

Correct matching of front and rear tires is critical to obtaining optimum performance and handling. Never mount a rear tire in front or vice versa. Combining a new tire with a worn rear tire may cause instability. Always consult your manufacturer before modifying your motorcycle’s tires from stock.

Checking Tire Inflation

Check your tire air pressure at least once a week and before long trips. Be sure to use an accurate pressure gauge.

Check your air pressure when the tires are "cold." The tires are "cold" when your motorcycle has been ridden less than a mile at moderate speed or after being stopped for three or more hours. Never release air from a hot tire in order to reach the recommended cold tire pressure. Normal riding causes tires to run hotter and inflation pressure to increase. If you release air when your tires are hot, you may dangerously under inflate your tires.

If your tires lose more than two pounds per square inch (2 psi) per month, the tire, the valve, or wheel may be damaged. Consult your local dealer for an inspection.

Use valve caps to keep valve cores clean and clear of debris and to help guard against air leakage

Break-in Period

In order for your new tire(s) to provide optimum performance, tires should be ridden very cautiously for the first 100 miles in order for the tread surface to be “Scuffed-In” and work properly. Directly after new tires are mounted, sudden acceleration, maximum braking, and hard cornering must be avoided. This will allow the rider to adjust to the feel and handling characteristics of the new tire and for the new tire to be “Scuffed-In” correctly in order to achieve optimum grip level.

Tire Loading

Riding your motorcycle in an overloaded condition is dangerous. Overloading causes excessive heat to build up in your tires. This can lead to sudden tire failure while the tire is overloaded or at some later date.

Safe Loading

Consult your motorcycle owner's manual for the motorcycle load limits and proper tire inflation that applies to your motorcycle and tires.

Never exceed the maximum load rating stamped on the tire sidewall of your tire or the maximum vehicle load rating, whichever is less. Before a trip, determine the total weight of luggage, equipment, and rider(s) to be added to your vehicle.

Never exceed the accessory restrictions and motorcycle load capacity found in the owner's manual, or the maximum load molded on the sidewall of the tire.

Tire Damage

Riding on damaged tires is dangerous. A damaged tire can suddenly fail. Have your tires regularly inspected by your local dealer for damage.

Spotting Damaged Tires

After striking anything unusual in the roadway, ask your local dealer to demount the tire and inspect it for damage. A tire may not have visible signs of damage on the tire surface. Yet, the tire may suddenly fail without warning, a day, a week, or even months later.

Inspect your tires for cuts, cracks, or splits in the tread and sidewall areas. Bumps or bulges may indicate a separation within the tire body. Have your tire inspected by a qualified tire service person. It may be necessary to have it removed from the wheel for a complete inspection.

Tread Depth

Inspect your tires for adequate tread depth. When the tire is worn to the built-in indicators at 1/32nd inch (0.8 millimeters) or less tread groove depth, or the tire cord or fabric is exposed, the tire is dangerously worn and must be replaced immediately.

Inspect your tires for uneven wear. Wear on one side of the tread or flat spots in the tread may indicate a problem with the tire or vehicle. Consult your local dealer.

Inspect your rims also. If you have a bent or cracked rim, it must be replaced.

Tire and/or Vehicle Storage

Tires and/or vehicles should be stored indoors in a cool, dry place where water cannot collect inside the tires. The tires and or vehicles should be placed away from electric generators and motors and sources of heat such as hot pipes.

Storage surfaces should be clean and free of grease, gasoline, or other substances, which can deteriorate the rubber. Improper storage can damage your tires in ways that may not be visible.

Oil, Grease, and Gasoline

These items can deteriorate rubber when exposed to a tire for any length of time. Use a clean, damp cloth to remove these chemicals from the tire.

Sidewall Treatment

Use a mild soap solution to clean sidewalls, white stripes, or raised white lettering, and then rinse off with plain water. Never apply any other materials, cleaners, or dressings to enhance sidewall appearance. These items may degrade the rubber and remove inherent ozone cracking and weather-checking resistance.
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Tire Conversion Charts

Motorcycle Street Tire Size Conversion Chart
Front Tires
Metric Alpha Inch
80/90 MH 2.50/2.75
90/90 MJ90 2.75/3.00
100/90 MM90 3.25/3.50
110/90 MN90 3.75/4.00
120/80 N/A 4.25/4.50
120/90 MR90 4.25/4.50
130/90 MT90 5.00/5.10
Rear Tires
Metric Alpha Inch
110/90 MP85 4.50/4.75
120/90 MR90 4.50/4.75
130/80 N/A 5.00/5.10
130/90 MT90 5.00/5.10
140/80 N/A 5.50/6.00
140/90 MU90 5.50/6.00
150/80 MV85 6.00/6.25
150/90 MV85 6.00/6.25
N/A
Motorcycle Off-Road Tire Size Conversion Chart
Front Tires
Metric Alpha Inch
60/100 90/80 2.50/2.75
70/100 90/90 2.75/3.00
80/100 100/80 3.00/3.25
Rear Tires
Metric Alpha Inch
80/100 80/90 2.50/3.60
90/100 110/90 3.60/4.10
100/100 120/80 4.00/4.10
110/100 130/80 4.00/4.50
120/100 140/80 5.00/5.10

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Size Types


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Motorcycle Speed Ratings

 
Speed Symbol Max Speed Speed Symbol Max Speed Speed Symbol Max Speed
J 62 mph K 68 mph L 75 mph
M 81 mph N 87 mph P 93 mph
Q 99 mph R 106 mph S 112 mph
T 118 mph U 124 mph H 130 mph
V 149 mph W 168 mph Y 186 mph

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Load Indexes (L.I.)

 
L.I. lbs.   L.I. lbs.   L.I. lbs.
33 254   49 408   65 639
34 260   50 419   66 661
36 276   52 441   68 694
37 282   53 454   69 716
38 291   54 467   70 739
39 300   55 481   71 761
40 309   56 494   72 783
41 320   57 507   73 805
42 331   58 520   74 827
43 342   59 536   75 853
44 353   60 551   76 882
45 364   61 567   77 908
46 375   62 584   78 937
47 386   63 600   79 963
48 397   64 617   80 992

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