Tyre size designation can be found on the tyre's sidewall with information about tyre:
- Tyre width in inches or mm
- Aspect ratio – ratio of height to width
- Construction type
- Speed index - Maximum allowed speed
- Rim diameter
- Load index - Maximum load capacity
1. Radial motorcycle tyres - designation in mm
Metric tyre size designation is the most common designation system. For example:
Designation: 190/50 ZR 17 M/C (73W) TL
Let's see what each symbol means.
- 195
- Tyre width in Millimeters (mm)
- /50
- Aspect ratio, ratio of height to width (50 : 100).
- ZR
- Radial construction.
- 17
- Rim diameter in inches.
- M/C
- For motorcycles only, to prevent mixing with car tyres. Motorcycle tyres must not be mounted on car rims.
- (73)
- Load index. See the load index table.
- (W)
- Speed index > = 270 km/h (allowed higher speed than 270 km/h). You may lookup the value in the speed index table.
- TL
- Tubeless tyre.
2. Bias ply (cross ply or diagonal ply) - designation in mm
Designation: 130/90 - 18 M/C 69 R TT
Symbols meaning:
- 130
- Tyre width in Millimeters (mm).
- /90
- Ratio of height to width (90 : 100).
- -
- Bias ply construction.
- 18
- Wheel diameter in inches.
- M/C
- For motorcycles only, to prevent mixing with car tyres. Motorcycle tyres must not be mounted on car rims.
- 69
- Load index – maximum permitted load. See the load index table.
- R
- Maximum permitted speed (R = 170 km/h). You may lookup the value in the speed index table.
- TT
- Tube type.
3. Bias ply - designation in inches
Designation: 4.00 - 18 M/C 64H TL
Symbols meaning:
- 4.00
- Tyre width in inches.
- -
- Bias ply construction.
- 18
- Wheel diameter in inches.
- M/C
- For motorcycles only, to prevent mixing with car tyres. Motorcycle tyres must not be mounted on car rims.
- 64
- Load index – maximum permitted load.
- H
- Maximum permitted speed (H = 210 km/h).
- TL
- Tubeless tyre.
4. Bias ply – alphanumeric designation
Designation: MT 90-16 T 71H TL
Symbols meaning:
- M
- Motorcycle.
- T
- Tyre width symbol, T = 5.10 inches.
- 90
- Ratio of height to width (90 : 100).
- 16
- Wheel diameter in inches.
- T
- Rim contour.
- 71
- Load index – maximum permitted load.
- H
- Maximum permitted speed (H = 210 km/h).
- TL
- Tubeless tyre.
5. Bias belted – designation in mm
Designation: 180/55 B 17 M/C 73Q TL
Symbols meaning:
- 180
- Tyre width in mm.
- /55
- Ratio of height to width (55 : 100).
- B
- Symbol for construction type – bias belted.
- 17
- Wheel diameter in inches.
- M/C
- For motorcycles only, to prevent mixing with car tyres. Motorcycle tyres must not be mounted on car rims.
- 73
- Load index – maximum permitted load.
- Q
- Speed index, maximum permitted speed (Q = 160 km/h).
- TL
- Tubeless tyre.
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