Dirt Bike Tire Number Decoding

Here is the answer to "what do the numbers on a dirt bike tire stand for". If there are any further question please feel free to contact me. If your looking for the best price on dirt bike bike tires make sure you check out our Knobby Tire Post.

Example 90/90/21
First 90-Tires width in milimeters
Second 90-Aspect ration or height of sidewall in this tires case (90% of the width)
21-Size of the rim.

Other Numbers On Tire
Arrow-Direction tire should rotate.
No Arrow-Non directional
Date Code Example-1014 10=Week 14=Year
Load Rating-Normally found after the tire size chart below to decode number.

           Front Tire

Metric	Alpha	Inch
80/90	MH90	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
120/90	MR90	4.25/4.50
130/90	MT90	5.00/5.10

             Rear Tires

Metric	Alpha	Inch
110/90	MP85	4.00/4.25
120/90	MR90	4.50/4.75
130/90	MT90	5.00/5.10
140/90	MU90	5.50/6.00
150/80	MV85	6.00/6.25
150/90	MV85	6.00/6.25

Metric	Alpha	Inch
80/90	MH90	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
120/90	MR90	4.25/4.50
130/90	MT90	5.00/5.10

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