Is the tyre I’m buying right for my two-wheeler? Should I trust the mechanic with the age of the tyre or is there a way I could check that myself? Why do tyres have markings on them?
If you have struggled with questions like these, then this article is for you. While some of the information on TVS Eurogrip may not be of much use to you as a driver, there are a few that you should consider while buying a tyre for your two-wheeler. An absence of these markings indicates that the tyre has not been inspected by our engineers or have failed the safety standards. So, look for them.
How to read tyre sidewall
7 primary markings on a tyre
For convenience, let’s take 185 / 60 R15 71 W as the marking on one of the tyres.
- First two or three digits: This number is the width of the inflated tyre in millimetres at its widest, sidewall to sidewall. In our example, 185 represents a 185mm wide tyre. A forward slash ‘/’ is used before the next code.
- Next 2 digits: This is a percentage denoting the aspect ratio between the height and width of the tyre. A higher number means a higher profile. In our example, the height of the tyre is 60% of its width.
- Alphabets B or R: These represent the construction of the tyre. B stands for belted bias or cross-ply construction and R stands for radial tyres, such as the one in our example. An absence of marking indicates a cross-ply tyre. Radial and Bias both have their advantages such as Bias tyres have sturdier sidewalls while Radial tyres run cooler at high speeds.
- Next 2 digits: Following the construct indicator, the 2 digits represent the diameter of the rim (wheel) in inches. The wheel in our example is 15 inches wide.
- 2 digits after wheel diameter: These digits, load index, indicate the load or weight the tyre can carry when properly inflated. The tyre in our example has a load index of 71 which means that it can carry 345 kg. To know the weight corresponding to different load indices, use this table:
- The last letter: The last code, either an alphabet or a combination of a letter and a digit, stands for the speed rating of the tyre. It is the fastest speed a tyre can run safely. It ranges from 5 km/h and goes over 300 km/h. In our example, W rating indicates that the tyre can safely run till 270 km/h. Here’s the complete list of speed rating codes and their respective speeds:
- 4 digits enclosed in an oval: You may be able to find this on the inner side of the tyre. These 4 digits show the date of production of the tyre – first 2 digits are the week number and the next 2 digits are the year. For example, 2319 would indicate the tyre’s manufacturing in the 23rd week of the year 2019. This is a handy way to check that you’re not being sold an old tyre as they tend to get hard over time and lose their efficiency.
Load Index Load in kg 62 265 63 272 64 280 65 290 66 300 67 307 68 315 69 325 70 335 71 345 72 355 73 365 74 375 75 387 Code km/h A1 5 A2 10 A3 15 A4 20 A5 25 A6 30 A7 35 A8 40 B 50 C 60 D 65 E 70 F 80 G 90 J 100 K 110 L 120 M 130 N 140 P 150 Q 160 R 170 S 180 T 190 U 200 H 210 V 240 Z over 240 W 270 (W) over 270 Y 300 (Y) over 300
Other important markings
- Temperature: Tyres marked with M+S (M&S) are all-season tyres. They have a self-cleaning tread and provide good traction even on muddy or snowy roads. M+T (or M&T) tyres are good for Mud and Terrain. These tyres perform great in more difficult terrains such as rocks, deep snow and loose gravel. Some tyres that are made for extremely cold and snowy roads will also have a ‘snowflake’ icon on them.
- Construct: A tubeless tyre will have a TL marking while tube-type tyre will be marked with TT.
- The direction of rotation: This is shown by an arrow. While installing the tyre, pay special attention to the head of the arrow and make sure the rotation follows it.
Over to you
While your vehicle is in motion, tyres are its only contact with the road. Therefore, tyres must be selected carefully with the correct specification. A tyre too wide for your vehicle may affect acceleration negatively and will be less efficient, while a sleek tyre on a high-performance two-wheeler might shred away in the first drive itself.
To ensure none of these instances happens, all credible manufacturers place the tyre’s critical parameters on it as universally accepted codes. Now that you are aware of their meanings, you can choose the right tyre for your vehicle and needs.