The sequence 190/55 ZR 17 M/C (75W) on a tyre sidewall carries several details. The first number is nominal width in millimetres; 55 is sidewall height as a percentage of that width. R denotes radial construction, 17 is rim diameter in inches, and M/C identifies a motorcycle tyre.
The final number and letter describe load and speed ratings, rather than physical size. When buying a replacement, compare the dimensions and ratings for both front and rear with the motorcycle maker’s specifications. A TUBELESS marking also calls for a compatible wheel, while an arrow on the sidewall shows the intended mounting direction.
The final four digits of the production-date code give week and year: 0320 means the third week of 2020. It is not an expiry date. Storage, use and damage affect condition, so inspect for cracking, bulges and uneven wear. If fit or condition is in doubt, ask a tyre professional to check it.