Every tire has a plethora of information stamped into the side of the tire, here is a list of what each of those mean:


  1. Brand name and registered trademark with type of tread pattern and/or product line.
  2. Nominal section width, expressed in metric, inche or alpha; see size chart below
  3. Ratio between tire section height and nominal section width.  The ratio is not indicated when section width is expressed in inches (eg. 3.5-18)
  4. Code for tire construction (" - " = Bias, "R" = Radial, "B" = Bias Belted).
  5. Nominal rim diameter size in inches
  6. "Motorcycle" is abbreviated form differentiates motorcycle tires and rims from those designed for other vehicles.  Shown on some models only.
  7. Expresses the tire's maximum load capacity (pounds) at the pressure indicated (psi); see load index chart below
  8. Speed symbol.  Indicates the tire's speed; see speed rating chart below.
  9. Tubeless (TL) or tubetype (TT), as applicable.
  10. Number of plies and material.
  11. Abbreviation of "US Department of Transportation."  Serves to indicate that the tire conforms to the regulations issued by the US Department of Transportation.  Includes the serial # of the tire.
  12. Last 4 numbers of the DOT number represent the construction date.  Example 3510 means the tire was produced in the 35th week of 2010.

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


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

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