Reading the various numbers on motorcycle tires
If you are the one who is looking for information about motorcycle tires and wondering what is the code on that tire? How is it important?
The tire code is indicated on the sidewall. To choose the tires of motorcycle, it is the best to study the code list carefully for smooth driving performance. Because the code on that motorcycle tire will tell us the width and wheel size. This will help us to choose the right tires for motorcycle. At present, there are two types of numerical readings on motorcycle tires. That is “the inch scale” and “the metric scale”.
The inch section is a code on the motorcycle tire. That are often found on old motorcycles tire and small motorcycles which the first set of numbers will indicate the width of the tread. The next number is a number that indicates the size of the rims. M / C indicates that this tire is a motorcycle tire. And the last set of numbers is the tire load index and speed index that the tire can support.
(Can be compared from the table below)
2.50-17 M/C 43P CM35
2.50 : The width of the tire in inches which has width 2.50 inches.
17 : A Diameter of the rim in inches
M/C : Tire designed especially for motorcycles.
43 : The maximum weight the tire can carry which it can support a weight of 155 kg (compared to the LOAD INDEX table)
P : The maximum speed that this tire can handle which the maximum speed is 150 kilometers per hour. (Compared with the SPEED INDEX table)
CM35 : A tire pattern code of motorcycles.
Metric scale
มาตราเมตริกเป็นการอ่านรหัสบนยางนอกรถมอเตอร์ไซค์ ที่มักจะพบได้ในรถมอเตอร์ไซค์รุ่นใหม่ และเป็นระบบที่สามารถบอกรายละเอียดได้อย่างชัดเจน ไม่ว่าจะเป็นความกว้างของหน้ายางนอก และเปอร์เซนต์ความสูงของแก้ม , เส้นผ่านศุนย์กลางวงล้อ , อัตราการรับน้ำหนักสูงสุดของยาง ไปจนถึงอัตราความเร็วสูงสุดที่ยางรับได้
The code meaning on the wheels
80/90-17 M/C 50P CM-545
80 : The width in millimeters which this tire has 80 mm.
90 : The height of the sidewall, measured in percentage of the tire width.
17 : It’s a diameter of the rim in inches.
M/C : Tire designed especially for motorcycles.
50 : The maximum weight the tire can bear which it can support a weight of 190 kg (compared to the LOAD INDEX table)
P : The maximum speed that this tire can handle which the maximum speed is 150 kilometers per hour. (Compared with the SPEED INDEX table)
CM545 : A tire pattern code of motorcycles.
When choosing a motorcycle tire, should consider carefully about the rim size, width of the tire, sidewall height and the way you use your motorcycle. To get the tires that meet your requirement and can be used effectively can help to prevent any accidents that may occur from riding a motorcycle as well.
At present, there are 3 methods for reading:
1. French
2. Inch Marking
3. แบบ ETRTO (The European Tyre and Rim Technical Organisation)
700 x 35c
700 : The outer tire diameter
35 : The width of tire
The INFLATE TO MIN.50 MAX.75 P.S.I is the minimum and maximum pressure that a tire can support.
In this example, the minimum pressure is 50 pounds and the maximum is 75 pounds.
24 x 1.75
24
: The outer tire diameter
1.75 : The width of tire
The INFLATE TO MIN.35 MAX.65 P.S.I is the minimum and maximum pressure that a tire can accept.
In the example, the minimum is 35 pounds and the maximum is 65 pounds.
(35-622)
ETRTO is the new standard and now it becomes a standard for bicycle tires, the ETRTO value is placed in brackets and placed at the end of French or Inch Marking
For example 700 x 35C (35-622)
35 : The width of tire
622 : The outer tire diameter
motoplex | August 4, 2020 | 0 | safety , Service , Tires
Motorcycle tires are very important, we’re not telling you anything you don’t already know. There are things you might not know and these thing are pretty important. Wear, tear, age, these are all things you need to have on your mind every day, every ride.
How old are your tires? Tires should never exceed 6 years of age. Keep that in mind if you ride daily, weekly or even a few times a year. A tire sitting in the garage all year can dry and rot and fall apart when it finally hits the road. Rubber is a temperamental beast.
The first thing you might ask is “What does DOT mean?” That’s a great questions and the answer makes sense. Department of Transportation (DOT). National Highway Traffic Safety Administration (NHTSA) regulate the tire safety standards. They do their best to handle your safety. They have a lot of say in how tires are made.
After the DOT on your tires, you’ll come across a series of numbers. The last 4 digits will tell you where your tires were manufactured. The first two numbers show you the week, the second pair indicates the year. This is a good way to help you follow the 6 year rule of thumb. Especially if you’re purchasing a used bike that you might not have all the details on.
And example of this is if the number is 1315. This tells you the tires were made in the 13th week of 2015. Dazzle your friends with this bit of math next time you’re looking over a friend’s bike.
As you know, there are far more numbers on your tires. What do the rest mean? These are just as important, if not more, because these are going to tell you the sizing of the tire. Like good pants, they need to be the right fit.
Many tire sizes work in metric, note that if you’re driving an American-made bike, they can still follow this format. It also doesn’t mean that the tires aren’t American made as well, it’s just how it’s done. Don’t panic.
A common tire size is 180/70R-16 so we’ll work off that. The first number you read is 180. This is the width of the tire in millimeters. The next number being 70 is the aspect ratio, this is the height of the sidewall. The height is 70% of the width or 126mm high. Fortunately this math is done from you by the manufacturer because this formula might have been one of the lessons in school you were sure you’d never need to know in real life. 16, the third number is the rim size. This is measured by the diameter. The letter between the second and third numbers, either R or B will inform you if the tire is Bias Ply or Radial. If there is no letter, the tire is Bias Ply.
A bias tire consists of multiple rubber plies over lapping each other. A radial tire has the sidewall and the tread to function as two independent features of the tire. There is an advantage to both and if you find that you’re putting a lot of thought into figuring out which might be better, this is a great opportunity to talk to a motorcycle professional.
So, you read all of this and you don’t see any of these metric numbers we’re referring to. That means you have Alpha Numeric Motorcycle Tire Sizes. Those are just as difficult to read but we have your back.
Let’s work off MU90B16 as an example. The first letters and two numbers are going to require you to reference a Street Tire Size Conversion Chart for all of the Letter Designation Breakdowns. You’ll want to also know if these are front or rear tires. You can find these online or by contacting a service center or tire store. The next letter, like on Metric, will inform you if the tire is Bias Ply or Radial. The last number will be rim diameter.
Dirt bikes and some older bikes use only numeric. An example being 5.00-16. In this case, 5.00 is the tire width in inches. 5.00 = 127 millimeters and the second number is rim diameter.
These are numbers you’re going to need to remember as they are all on your bike tires. Plus when you’re purchasing online or in a store there is plenty of help to assure you’re getting the right sizes. But maybe today you learned a little something that you can pass on to the motorcycling youth of tomorrow. If by the time they are riding we all don’t have flying bikes.
Podolsk,
15 km Simferopol highway To contacts
#service #info
8 years ago
Only two small contact patches of motor rubber connect to the road motorcycle. Their total area is less than the area of the sole of the boot. Acceleration to 60 in 3 seconds, cornering at 250 mph, braking from 300 mph to 0 - all this happens in a tiny area of these two spots.
Tires are essential for motorcycle performance and rider safety.
When you change the type or model of tires, the behavior of the motorcycle on the road changes. Therefore, it is important to choose the right motor rubber. The required tire parameters for a particular motorcycle are indicated in the manual. Tire make and model are often listed. In this case, the characteristics of the specified model are taken as the necessary characteristics.
Sport - sports tires. They have the best traction and the shortest service life. Wear out in less than 3 thousand kilometers. The rubber compound is optimized for high temperature performance. The shape of the rubber is designed to maintain a sufficient footprint in deep corners at high speed. If the temperature is too low, the performance of the tire drops dramatically. The use of such rubber in the city is unsafe due to the impossibility of maintaining the operating temperature. In race conditions, the temperature of the tires is maintained with the help of heating pads and warm-up circles; it is very difficult to warm up the tires in the city, because. you have to stop, and it is difficult to constantly maintain a high speed.
Sport Street - tires for aggressive street driving. Allows you to take turns at high speeds with a strong tilt of the motorcycle. They do not require preheating, but tire performance deteriorates when overheated.
Sport Touring - have the best balance between road grip and service life.
Touring - have the longest life and good grip at low rubber temperatures. Suitable for use in cold climates. Not designed for deep cornering at high speed.
Off road - have an angular and deep tread. Designed for stable movement on the ground, mud, sand, gravel. On asphalt pavement, stability is reduced.
All the necessary information is on the side of the rubber: type of rubber, its type, size, cord design, speed characteristics, maximum load, maximum pressure, country of production and certification, manufacturer and model, date of manufacture , labels to install. For example:
180/55 ZR-17 (73W) TL
180 - width in millimeters
55 - height in percent of width
9001 Z-speed rating It is deciphered according to the table.R - cord type. R - radial. D - diagonal. The radial cord is lighter and is used on sportbikes. Diagonal plywood is better for shock loads and is more suitable for heavy cruisers.
17 - disc diameter in inches.
73 - load index. The load in kilograms for which the tire is designed.
W - speed index. The speed the tire is designed for. Tires with a low speed and load index are cheaper, but if the design parameters are exceeded, the tire may burst.
TL is an abbreviation for the type of rubber. TL (TubeLess) - tubeless. TT (Tube Type) - chamber.
Maximum pressure rubber is indicated on the bead in kilopascals and pounds per square inch. For example, 290 KPA (42PSI) COLD means the corresponding maximum cold pressure. Under-inflated rubber has a significantly reduced service life and performance. Therefore, in addition to daily visual control, it is necessary to check the pressure with a pressure gauge, especially before long trips and at least once a week. On one of the sides there is a yellow dot or a red . Manufacturers recommend combining the yellow dot with a valve. The yellow dot indicates the lightest part of the tire in terms of static balance. Strictly speaking, it must be combined with the heaviest point of the disk. But on a flat disk, this point will always be a valve. We saw a red dot only on metzeler rubber, the manufacturer also recommends combining it with a valve.
Rotation arrow or simply an arrow indicates the direction of rotation.
Front (front), F, Rear (rear) - indication of the front or rear wheel. Also relevant for some models of scooters.
The date of manufacture of the tire is indicated by the numbers in the oval. The first two digits indicate the week number. The next one or two digits indicate the year number. For example, 3507 is the thirty-fifth week of 2007. The older the tire, the higher the risk that it could deteriorate as a result of improper storage. In various countries it is forbidden to sell tires older than 3 or 5 years. But its use is not prohibited. Therefore, when buying tires older than 5 years, you need to carefully evaluate its condition.
SIDEWALL NYLON1 TREAD NYLON 2+ARAMID 2 - designation of the type and number of cord layers (nylon, nylon or metal).
DOT, E with number, ECE certification information.
Tire must be changed when the wear of the rubber has reached at least one indicator (small protrusions in the grooves of the tread). Old rubber without mechanical wear may lose its performance due to long-term exposure to sunlight, low temperatures or its sudden changes. The rubber may become "hard", microcracks or visible cracks may appear on it. In this case, the tires need to be replaced.
Today we will figure out what is what in the markings of motor rubber.
Let's start with the fact that there are 4 types of such markings in the world:
The metric marking system is found in our country much more often than others. In its classic form, it is approximately the following code: 120/70 - Z17 M / C. All its elements are in strict order. Let's consider each of them in more detail.
The first number (in our case 120) indicates the width of the tire in a straight line from edge to edge. In the metric marking system, it is measured in millimeters.
The second digit (in the example it is 70) indicates the height of the tire profile including the tread. It is expressed as a percentage of the tire width in mm.
Using a tire with a rim width or height not specified by the motorcycle manufacturer may result in loss of cornering dynamics, increased fuel consumption and reduced tire life.
Next are the Latin letters. The first letter (Z) means that this is a high-speed tire and can be used at speeds over 240 km/h.
The letter W is a speed index, that is, an indicator, the excess of which negatively affects the condition of the tire and reduces its life. Latin speed index designations are international and are used in all types of motor rubber markings.
Below we present a summary table of speed indices.
Speed indices
| Designation | km/h | mph |
| B | 50 | 31 |
| C | 60 | 37 |
| D | 65 | 40 |
| E | 70 | 44 |
| F | 80 | 50 |
| G | 90 | 56 |
| J | 100 | 62 |
| K | 110 | 68 |
| L | 120 | 74 |
| M | 130 | 81 |
| N | 140 | 87 |
| P | 150 | 93 |
| Q | 160 | 100 |
| R | 170 | 106 |
| S | 180 | 112 |
| T | 190 | 118 |
| U | 200 | 124 |
| H | 210 | 130 |
| V/VB | to 240 | to 149 |
| (V)/(VB) | over 240 | over 149 |
| W | to 270 | to 168 |
| (W) | over 270 | over 168 |
| ZR | over 240 | over 149 |
The last number (17 in our case) is the rim diameter. Even in the metric marking system, this parameter is measured in inches. Fitting a tire designed for a 16" rim on a 17" rim won't work (and if you can, it won't end well).
The letter combination M/C indicates that the rubber is intended specifically for motorcycles.
In addition to the main code (120/70 - Z17 M / C), other information can be encrypted in different parts of the bus.
First of all, it is necessary to say about the load index (see picture). It shows the maximum weight that the tire can support when fully inflated. The load index table is presented at the bottom of the page.
A special arrow (sometimes labeled Wheel Rotation) indicates the direction of rotation.
The code TUBE or TT means that the tire must be used only with a tube, and TUBELESS or TL says that it is tubeless.
On some tires you can see the abbreviation DOT. It is applied to the models, complies with the safety standards of the US Department of Transportation. The abbreviation EUCX means the same certificate issued by one of the EU countries.
The letter B in a circle is a sign of approval according to the results of tests within the framework of UNECE regulations, the number next to it is the country where the test was carried out.
The date of manufacture of the tire can be understood from the last four digits in the oval, for example 4207 - 42nd week of 2007.
Load indices
| Designation | kg | Designation | kg | Designation | kg | Designation | kg |
| 20 | 80 | 37 | 128 | 54 | 212 | 71 | 345 |
| 21 | 82. | 38 | 132 | 55 | 218 | 72 | 355 |
| 22 | 85 | 39 | 136 | 56 | 224 | 73 | 365 |
| 23 | 87.5 | 40 | 140 | 57 | 230 | 74 | 375 |
| 24 | 90 | 41 | 145 | 58 | 236 | 75 | 387 |
| 25 | 92. | 42 | 150 | 59 | 243 | 76 | 400 |
| 26 | 95 | 43 | 155 | 60 | 250 | 77 | 412 |
| 27 | 97 | 44 | 160 | 61 | 257 | 78 | 425 |
| 28 | 100 | 45 | 165 | 62 | 265 | 79 | 437 |
| 29 | 103 | 46 | 170 | 63 | 272 | 80 | 450 |
| 30 | 106 | 47 | 175 | 64 | 280 | 81 | 462 |
| 31 | 109 | 48 | 180 | 65 | 290 | 82 | 475 |
| 32 | 112 | 49 | 185 | 66 | 300 | 83 | 487 |
| 33 | 115 | 50 | 190 | 67 | 307 | 84 | 500 |
| 34 | 118 | 51 | 195 | 68 | 315 | 85 | 515 |
| 35 | 121 | 52 | 200 | 69 | 325 | 86 | 530 |
| 36 | 125 | 53 | 206 | 70 | 335 | 87 | 545 |
You can see all of the listed metric marking codes for motor tires and professional comments on them in the video below.
This type of marking of motor rubber is used infrequently and is used mainly for touring tires. Let's analyze a specific example: MT90S-16.
A system that was heavily used in the 1990s and has now been largely phased out. It differs from the metric one only in the unit of measurement of the tire width (instead of millimeters inches), as well as the absence of the tire profile height indicator in the marking (by default, this parameter is considered to be equal to the width).
As the name suggests, used for low profile tyres. Example: 4.25/85H-18. The first number is the tire width in inches, the second is the profile height expressed as a percentage of the width, H is the speed index, 18 is the rim diameter.
Summary table of tire sizes in various marking systems
| Permitted rim widths | Metric | Alpha | Standard in inches | Low profile in inches |
| 1. | 70 | MG | 2.75 | - |
| 1.60, 1.85 | 80 | MH | 3.00 | 3.60 |
| 1.85, 2.15 | 90 | MJ | 3.25 | 3.60 |
| 1.85, 2.15 | 90 | ML | 3.50 | 4.10 |
| 2.15, 2.50 | 100 | MM | 3.75 | 4.10 |
| 2.15, 2.50, 2.75 | 110 | MN | 4.00 | 4. |
| 2.15, 2.50, 2.75 | 110 | MP | 4.25 | 4.25/85 |
| 2.15, 2.50, 2.75 | 120 | MR | 4.50 | 4.25/85 |
| 2.15, 2.50, 2.75 | 120 | MS | 4.75 | 5.10 |
| 2.50, 2.75, 3.00 | 130 | MT | 5.00 | 5.10 |
| 2.75, 3.00, 3.50 | 140 | MU | 5.50 | - |
| 3.50, 4.00 | 150 | MV | 6. |
