Have you already looked at your tyres and asked yourself what the figures and letters on the sidewalls stand for? We'll tell you.
180/55 ZR 17 M/C (73W) TL
| 180 | : | Tyre width [mm] |
| 55 | : | Section ratio [%] |
| ZR | : | Identifier for tyre style |
| 17 | : | Rim diameter [inch] |
| M/C | : | Tyres exclusively for motorcycles |
| 73 | : | Tyre load identifier |
| W | : | Speed symbol |
| TL | : | Tubeless tyres |
Tyre size
In the course of the development different kinds of identifiers for tyre sizes have emerged.
Conventional labelling
e.g.:
2.75 - 17, 3.50 - 18, 4.00 H 18
4.00 - 18 64 H, 3.25 - 19 54 V
Millimetre low section label
e.g.: 110/90 - 18, 130/80 - 18, 110/90 - 19
Tyre style
The term "tyre style" distinguishes the tyres according to their carcass design:
Tyres in diagonal design
Tyres in the diagonal design, formerly referred to as the conventional tyre style, are identified with a hyphen in the size identifier, e.g.: 3.50 - 19, 23/4 - 17, 3.25 - 21
Tyres in diagonal belt design
Tyres in the diagonal belt design, also called radial belt tyres or bias belted tyres, are labelled with the identifying letter B in their size label, e. g.: 140/80 VB 17, 150/80 VB 16 V250
Tyres in radial belt design
Tyres in the diagonal belt design, also called radial belt tyres or radial tyres, are labelled with the identifying letter R in their size label, e. g.: 140/80 R 17 69 H, 160/60 ZR 18
Tyre load identifier
The maximum tyre load (in lbs) and the maximum tyre pressure (in psi) for cold tyres are stated on all road tyres. Details about the conversion from the tyre load identifier to real kg values are available on the web site conversion table in the section "Driving safety". Some tyres have got the additional information "reinf." in the factory identifier, which is equal with the detail "6 PR" or "Load Range C"; it shows that the tyre is of a reinforced design with a higher tyre load capacity. This higher tyre load capacity is already taken into consideration in the tyre load identifier. Please contact the customer service of the tyre manufacturer regarding the possibility of a higher tyre load capacity than the one stated for lower speeds.
Speed symbol
The maximum permissible speed for a tyre is stated with the speed symbol (details of the conversion from the speed symbol to real km/h values are available on the web site conversion table in the section "Driving safety"). For tyres of more than 210 km/h the maximum permissible speeds are stated in the technical tables. The term "speed category" distinguishes the motorcycle tyres according to their permissible maximum speeds.
Additional identifiers
The labels on the sidewalls must be stated on the basis of legal regulations in different countries. Tyre identifiers in English, e.g. load (tyre load capacity) in lbs, inflation pressure (tyre pressure) in psi, only apply to countries, where the legal regulations apply according to the DOT standard. For the complete description and explanation of the identifiers, please refer to the section "Further identifiers".
Further identifiers
| Metzeler | Brand name |
| Roadtec Z6 | Product description |
| Steel Radial | Description of radial tyre concept |
| 180 | Tyre nominal width in mm |
| 55 | Section ratio: this percentage states the ratio of the tyre section height to the tyre nominal width. Not applicable if the section width is stated in inches. |
| ZR | Identifier for tyre design ("-": diagonal, "B": diagonal belt, "R": radial) |
| 17 | Rim diameter in inches |
| M/C | Abbreviation for motorcycle. Helps to distinguish motorcycle tyres and rims from tyres and rims for other vehicles.
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| 73 | Tyre load identifier, it states the maximum load as permissible. For values in kg refer to the conversion table. |
| W | Speed symbol, states the maximum permissible speed. For values in km/h / mph refer to conversion table. |
| TL | Tubeless, without tubes. The tyre may be mounted without tubes. For information about the use of tubes in tubeless tyres refer to the section "Driving safety". |
| Made in Germany | escribes the country of origin of the tyre. Running direction arrow = The arrow identifies the prescribed running direction of the tyre, depending on the mounting position (front or rear). If in exceptional cases a rear tyre is used as a front tyre the tyre must be mounted against the running direction arrow. The mounting of front tyres as rear tyres is not permissible.
|
| Driving wheel | states that the running direction is referring to the driving wheel (rear wheel). |
| E3 | Identifier for the country, in which the tyre has been homologated. |
| 75R-xyz | Tyre identifier according to ECE R 75. |
| Max. load ... | Detail of maximum permissible load, which the tyre may bear with the prescribed pressure in a cold state. |
| DOT | Abbreviation for Department Of Transportation = US Ministry of Transport. Proof that the tyre meets the regulations in the USA and Canada.
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| 3403 | the first two digits describe the production week (34.), the final two describe the production year (2003) of the tyre.
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| Tread | describes the number of the carcass and belt layers and the relevant material. |
| TWI | Abbreviation for Tread Wear Indicator. Describes the profile wear indicator in the main furrows, which become visible from the profile depth of roughly 1.6 mm. |
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