What do the numbers on motorcycle tyres mean?

Tyre model marks are mostly shaped like: 215/70R15. The meanings of these numbers are:

1.215 represents the width of the tread, the unit is mm, the width of the general tire is between 145-285mm, and the interval is 10mm;
2.70 is the aspect ratio, that is, the ratio of the tire sidewall height to the tread width. 70 represents 70%. The aspect ratio of the general tire is between 30% and 80%. Under normal circumstances, ordinary cars should not use aspect ratio >75% Tires with a flatness ratio of <60% are recommended for luxury cars and high-performance sports cars;
3.R is the abbreviation of English Radial, which means that the tire has a radial layer structure;
4.15 is the outer diameter of the rim, in inches.
5.If some tires are marked like: 6.00-12, this indicates that it is not a radial tire, but a bias tire. This type of tire is rarely seen on cars, due to its poor safety, load capacity and high-speed stability. Therefore, it is only applied to some low-end off-road vehicles and heavy trucks.