When buying a motorcycle, you will notice that the user manual and the plates have a ton of information. The information included here should help you get the best from your motorcycle and ensure that you operate within specifications.
However, some numbers may be confusing, especially if you have no prior knowledge about bike operations. For example, the motorcycle tire sidewalls have numbers that should guide fitment and pressure limits, like the 73W.
Unfortunately, most riders cannot tell what this number means, and if you are one of them, it is time to make some changes. Therefore, we will explain in detail the meaning of this number to help you be in tune with your motorcycle.
What 73w on Your Motorcycle Wheel Means
A 73W on a tire means that the load rating is (73) and the speed index is rated (W). The number 73 indicates that the maximum tire load can carry 365 kg (805 lbs.) when inflated to maximum pressure. The W indicates the maximum speed at which the tire can be used, which is 270 kph (168 mph). This is the speed the tire can handle when inflated to the maximum pressure and carrying the maximum designated load of 365 kg (805 lbs.)
The speed symbol is the maximum speed at which a tire can carry a load corresponding to its load index under service conditions. The speeds indicated on the motorcycle tire are given when inflated to the correct pressure, operated with specified load limits, and fitted onto the appropriate rim size.
The speeds indicated should be used as the maximum the tire can handle and not the normal riding speed. For example, V, W, and Z-rated tires are usable at higher speeds but with reduced load.
Here’s a table showing all motorcycle speed ratings:
|Speed Rating Code||Physical Meaning|
|F||Up to 50 mph (80 km/h)|
|J||Up to 62 mph (100 km/h)|
|K||Up to 68 mph (109 km/h)|
|L||Up to 75 mph (121 km/h)|
|M||Up to 81 mph (130 km/h)|
|N||Up to 87 mph (140 km/h)|
|P||Up to 93 mph (150 km/h)|
|Q||Up to 99 mph (159 km/h)|
|R||Up to 106 mph (170 km/h)|
|S||Up to 112 mph (180 km/h)|
|T||Up to 118 mph (190 km/h)|
|U||Up to 124 mph (200 km/h)|
|H||Up to 130 mph (210 km/h)|
|V||Up to 149 mph (240 km/h)|
|Z||149+ mph (240+ km/h)|
|W||Up to 168 mph (270 km/h)|
|(W)||168+ mph (270+ km/h)|
|Y||Up to 186 mph (299 km/h)|
|Scooter||Up to 62 mph (100 km/h)|
|Flotation Type||Up to 50 mph (80 km/h)|
Motorcycle Tire Load Index
The load index is a numerical code that associates with the maximum load a tire can carry except for loads at speeds exceeding. When fitting replacement tires, only use the ones with the precise speed and load index issued by the manufacturer’s handbook.
Here’s a table showing the maximum load carrying capacity of a tire depending on the Load Index (LI):
Before making any variation, consult with a professional service team or tire brand to ensure the replacement is the correct fitment for your motorcycle.
Example of a Motorcycle Tire Rating
180/55 ZR 17 M/C (73W) TL
The first number on the tire sidewall indicates the width of the tire. This figure is given in millimeters and taken from the tire’s widest section.
The second number on the sequence represents the tire’s aspect ratio (height). This number is a percentage of the tire’s width. In this example, the tire’s height is 55% of 180 mm, equating to 99 mm.
This symbol is the first two-speed rating within the code and indicates the at which the tire can exceed. For example, the ‘Z’ means that the tire is built for speeds over 149 mph. However, it does not give information about the maximum tolerable speed of the tire. This information is located further in the bracket.
The R is an indication of the construction type of the tire. When you see the letter ‘R’ on a tire, it is radial construction. Here is a detailed explanation of the radial tires;
- Radial – A tire with the cord plied arranged in a perpendicular (90-degree angle) to the direction of travel.
- Belted (B) – A belted bias tire begins life as a normal bias-ply tire. Stabilizer belts are added onto the existing plies at different angles to improve performance over non-belted, bias-ply tires called cross-ply tires.
This number represents the size of the wheel that the tire can fit. This measurement is given in inches meaning this tire fits perfectly in a 17-inch diameter wheel.
This means that the tire should be for motorcycles.
This number in the bracket represents the tire’s load index, specifying the maximum load the tire can carry. To find the corresponding weight to this tire, you need to find a load index table. For example, this tire can carry loads up to 365 kg (805 lbs).
The ‘W’ given in brackets is the second speed rating found on the tire. The load you put on a tire directly affects the maximum capable speed. The ‘W’ is placed beside the load index because it is the maximum tire speed carrying its maximum load. For example, if you load the tire with 365 kg, the tire’s speed rating will be 168 mph per the above speed index.
TL shows that a tire is tubeless. ‘TT’ is a tube-type tire with an inner tube.
If you want more information, here’s a great video explaining the tire sidewall letters and numbers:
What Should you Consider When Selecting Motorcycle Tires
Date of Manufacture
The manufacturing date appears on the tire’s sidewall as a 4-digit number. For example, 0622 would indicate that the tire was manufactured in the 6th week of 2022. Do not forget that the ’06’ represents the week, not the month.
It is advisable to use a tire that is less than 6 months old, and the ones that are older than 12 months to be avoided. Check also the storage of the tire. Ideally, tires must be kept in cool temperatures further from direct sunlight.
The tire manufacturer will recommend the appropriate tire size and rating for your motorcycle. Ensure that you check the sidewall and compare it with the recommended sizes by the manufacturer.
Your motorcycle tires are critical to your motorcycle’s overall performance and driving experience. Ensure that you know the right size when buying replacement tires. In addition, change tires only when worn out and stick to these figures to stay within the load and speed indices.
Hi, my name is Niklas, the head content creator & CEO of Whirling Wheelz. I am very interested in vehicles of all kinds, mainly cars. I have a car mechanics degree from high school and a big hobby of mine is to follow the WRC (World Rally Championship) both online and through travel.