Speed and Construction
As with four-wheeled vehicles, tyres for motorcycle have a tyre code, which describes a tyre's width, height/width aspect ratio, wheel diameter, load index and speed rating. The most common are:
- 3 digit number: The "nominal section width" of the tyre in millimetres; the widest point from both outer edges.
- /: Slash character for character separation.
- 2 or 3 digit number: The "aspect ratio" of the sidewall height to the total width of the tyre, as a percentage.
- An optional letter indicating construction of the fabric carcass of the tyre:
- B: bias belt (where the sidewalls are the same material as the tread, leading to a rigid ride)
- D: diagonal
- R: radial
- if omitted, then it is a cross ply tyre
- 2 digit number: Diameter in inches of the wheel that the tyre is designed to fit.
- 2 or 3 digit number: Load index; see table below
- 1 or 2 digit/letter combo: Speed rating; see table below
Load index
| LI | kg | LI | kg | LI | kg | LI | kg | LI | kg |
|---|---|---|---|---|---|---|---|---|---|
| 19 | 77,5 | 36 | 125,0 | 53 | 206 | 70 | 335,0 | 87 | 545,0 |
| 20 | 80,0 | 37 | 128,0 | 54 | 212,0 | 71 | 345,0 | 88 | 560,0 |
| 21 | 82,5 | 38 | 132,0 | 55 | 218,0 | 72 | 355,0 | 89 | 580,0 |
| 22 | 85,0 | 39 | 136,0 | 56 | 224,0 | 73 | 365,0 | 90 | 600,0 |
| 23 | 87,5 | 40 | 140,0 | 57 | 230,0 | 74 | 375,0 | 91 | 615,0 |
| 24 | 90,0 | 41 | 145,0 | 58 | 236,0 | 75 | 387,0 | 92 | 630,0 |
| 25 | 92,0 | 42 | 150,0 | 59 | 243,0 | 76 | 400,0 | 93 | 650,0 |
| 26 | 95,0 | 43 | 155,0 | 60 | 250,0 | 77 | 412,0 | 94 | 670,0 |
| 27 | 97,5 | 44 | 160,0 | 61 | 257,0 | 78 | 425,0 | 95 | 690,0 |
| 28 | 100,0 | 45 | 165,0 | 62 | 265,0 | 79 | 437,0 | 96 | 710,0 |
| 29 | 103,0 | 46 | 170,0 | 63 | 272,0 | 80 | 450,0 | 97 | 730,0 |
| 30 | 106,0 | 47 | 175,0 | 64 | 280,0 | 81 | 462,0 | 98 | 750,0 |
| 31 | 109,0 | 48 | 180,0 | 65 | 290,0 | 82 | 475,0 | 99 | 775,0 |
| 32 | 112,0 | 49 | 185,0 | 66 | 300,0 | 83 | 487,0 | 100 | 800,0 |
| 33 | 115,0 | 50 | 190,0 | 67 | 307,0 | 84 | 500,0 | - | - |
| 34 | 118,0 | 51 | 195,0 | 68 | 315,0 | 85 | 510 | - | - |
| 35 | 121,0 | 52 | 200,0 | 69 | 325 | 86 | 530,0 | - | - |
Speed rating
| Rating | Speed (km/h) | Speed (mph) |
|---|---|---|
| Moped | 50 | 30 |
| J | 100 | 62 |
| K | 110 | 69 |
| L | 120 | 75 |
| M | 130 | 81 |
| P (or-) | 150 | 95 |
| Q | 160 | 100 |
| R | 170 | 105 |
| S | 180 | 113 |
| T | 190 | 118 |
| U | 200 | 125 |
| H | 210 | 130 |
| V | 240 | 150 |
| W | 270 | 168 |
| Z | over 240 | over 150 |
Read more about this topic: Motorcycle Tyre
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