Motorcycle tires come with several numbers and letters, and symbols on their sidewalls. For a first timer, they can seem both cryptic and overwhelming.
I know this because that’s how I felt! But with a bit of research and education, I was able to get on top of things, which has served me quite well ever since.
In this post, I am going to explain various numbers, letters and symbols commonly observed on tyres.
A 73W on a tyre stands for the load rating (73) and speed index (W), respectively. The number 73 indicates the maximum load the tyre is built to carry (805 lbs or 365 kg) when inflated to the maximum recommended tyre pressure. And W indicates the maximum speed at which the tyre can be used (168 mph or 270 kph) when inflated to the maximum pressure and carrying the maximum designated load of 805lbs or 365kg.
Let’s look at some other examples.
What does 80H on a motorcycle tire mean? The 80 corresponds to a max load carrying capacity of 992lbs or 450kg. The H corresponds to 130mph or 210kmh.
What does 58W mean on a motorcycle tire? The 58 implies that the tire can bear a maximum weight of 520lbs/236kg and the H implies can safely go upto 168mph/270kph.
What the different numbers and markings on a tire and what do they mean?
Let’s look at in detail what the letters, numbers and symbols on a tyre mean.
The following video is of the rear tyre of my Kawasaki Z900, in this case mine is a Metzeler Sportec M9.
The markings on the tyre read Metzeler Sportec 180/55 ZR 17 M/C (73W) TL
Let’s break down each one of those letters and numbers.
This is the very first number in a series of numbers and letters. This is the width of the tire measured in millimetres. So 180 millimetre is the width of the tyre taken from one widest point of the tyre to the other. In general the wider the tyre the more stable it is for cruising and for straight lines. However, one must always look the profile of the tire overall — the height in conjunction with the width. So a 180/55 would offer stiffer sidewalls compared to 180/60. On supersports or superbikes meant for the track, you’d probably want the 55 and not the 60 since, 55 would be slightly more pointed in its curvature making it easier for your to corner.
This the height of the sidewall measured from wheel rim to top expressed as a percentage of the width. So in this case, the sidewall is 55% of the width which is 99 millimetres. The absolute value is therefore 99 millimetres.
This is speed index rating of the tire. Z means that the tire is good for speeds up 149mph or 240kph. This is highest rating that manufacturers give motorcycle tyres.
Some other ratings that indicate higher speeds are Y or V300 both of which indicate tire speed capabilities of 186mph or 300kph. Similarly, V290 indicates maximum speeds of 180mph and 290kph.
Radial tires are denoted by a R. Radial picked up in adoption in the 80s for motorcycles. They largely replaced the bias-ply tires. Radial tires get their name because of the radial construction of the steel cord. Those are laid perpendicular to the direction of travel or radially to the center of the tire.
While bias-ply tires are preferred for dirtbikes, adventure bikes with steel spokes and as cruiser replacement tires. Sport, supersports and superbikes typically use radial tubeless tyres.
If the tyre was not a radial tire but a bias-ply tire, then that could have been indicated by either a hyphen right after the height of the sidewall or simple as letter B instead of the the R.
This refers to the inner diameter of the tyre measured in inches. This is equal to the diameter of the rim.
This stands for type of vehicle — in this case a Motorcycle.
This numerical code represents the maximum weight the tire can carry when inflated to the correct pressure. In this case that maximum weight is 805lbs or 365kg as per the load index chart.
W indicates the maximum speed at which the tire can be used–which is 168 mph or 270 kph, when inflation pressure is maximum as per the manufacturer of the tire it is carrying the maximum designated load of 805lbs or 365kg.
This is an indication that this is a tubeless tyre. The only other combination would be TT which would mean a Tube Tire.
What should I keep in mind when selecting the best tyre for my motorcycle?
Here’s what you should keep in mind while buying a tire.
Date of manufacture
This is specified on the sidewall of the tyre as a 4 digit number. For example, 0522 would be that the tire was manufactured in the 5th week of 2022. Please note that 05 here denotes the week and not the month!
Best case scenario is to use a tire which is not older than 6 months. In any case, avoid tires older than 12 months.
Also, check how the tire was stowed. Tires should ideally be stowed in cool temperature away from direct sunlight and open air.
The manufacturer of your motorcycle will recommend tyre size and rating. Also make sure that you don’t stray away from those.
Practical feedback from fellow riders
I always reach out to my fellow riders about their experience with a certain tire brand, model and size. I also research online forums to pick up useful nuggets from chatter.
Motorcycle tire load index table:
|CODE||POUNDS (lbs)||KILOGRAMS (kg)|
Motorcycle speed index table:
|CODE SYMBOL||MAX SPEED IN MPH||MAX SPEED IN KPH|
|V or V240||149||240|
|W or V270||168||270|
|Y or V300||186||300|
|Z||above 149||above 240|
The tires on your motorcycle are a critical part of the overall riding experience and safety. Make sure you know the right size when buying new tires. Also, make sure to change tires when they are worn out and never exceed the load and safety limits of the tire!
Found the marking on a tire fascinating? Learn more about Motorcycle Trivia.