OG MotoWorks · Waalwijk
How do I read my tyre size?
The side of your tyre shows a code like 180/55 ZR17 (73W). Here's how to read it.
By Freddy · 20 October 2026
Example: 180/55 ZR17 (73W)
180/55 ZR17 (73W)
- 180 Width
- The width of the tyre in millimetres.
- 55 Profile
- The height of the sidewall as a percentage of the width: 55% of 180 mm is about 99 mm.
- Z Speed
- Z means: suitable for more than 240 km/h. On ZR tyres, the exact speed rating is often shown in brackets after the size.
- R Radial
- R stands for a radial tyre. If there's a dash (-) or B, it's a bias-ply (cross-ply) tyre.
- 17 Rim size
- The diameter of the rim in inches. Tyre and rim must be exactly the same size.
- 73 Load index
- The load index: how much weight the tyre may carry. 73 stands for 365 kg.
- W Speed rating
- The maximum speed of the tyre. W is up to 270 km/h, V up to 240 km/h and H up to 210 km/h.
Front and rear are different
Your front tyre is narrower than your rear tyre. A common combination on sports and naked motorcycles is 120/70 ZR17 front and 180/55 ZR17 rear. So always note down both sizes.
Where do I find my tyre size?
- On the side of your tyre (the sidewall), in large numbers.
- In your motorcycle's owner's manual, under the technical data.
- No idea? Send us a photo of the sidewall of your tyre via WhatsApp and we'll read it for you.
How old is my tyre?
The sidewall also shows a DOT code. The last four digits are the production week and year: 2324 means week 23 of 2024. Even a tyre with plenty of tread gets harder over the years and then gives less grip.
Other markings
- TL (tubeless): tyre without an inner tube. TT (tube type): with an inner tube.
- M/C: motorcycle tyre.
- Front or Rear: only for the front or only for the rear.
- An arrow shows the direction of rotation; it must be right when fitting.
Always choose a size that is approved for your motorcycle. Not sure which tyre fits? Message us and we'll help you choose.