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How to read motorcycle tire size numbers


Motorcycle Tire Size Meaning Explained

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By mts on

Motorcycle tires have size codes, a set of numbers and letters, which represent different factors like width, aspect ratio, speed rating, rim size, construction, type of the tire, load and speed indices, type of tube and the like. These sets of numbers and letters may either be measured in Metric, Alpha, or using the rare Standard Inch. These are called measurement systems, and they help you know the size of your tire. There are three major systems and each has a different format, which is why it is important to have the motorcycle tire size meaning explained, so you can learn – in order to buy the right tire for your bike.

Metric System

This system measures the size in millimeters. It is the most commonly used system for motorcycle tires, which is a set of three numbers and letters implying the width of the tire, the aspect ratio of the tire (ratio of tire‘s height to the width) and lastly the rim size given in inches. Immediately after the speed rating, you will find a letter or two letters used to signify the speed rating and the radial construction of the tire consecutively.

Click Here For Tire Pressure Gauge

Let us look at an example of this rating from a Shinko motorcycle tire 190/50 ZR 17:

  • 190 =width of the tire,
  • 50 = aspect ratio which is the percentage of the height of the tire to the tire’s width,
  • Z = speed rating which is above 149mph,
  • R= Radial construction
  • 17= size of rim which is 17 inches

However, the speed rating and the construction of the tire may not be indicated. In this case you will have a set of number in this manner: 100/90 – 19. This Shinko tire reading means it is 100 mm wide, with a 90% aspect ratio and can be mounted on to a rim of 19 inches.

In short, Metric measurement takes either the Width/aspect ratio-rim size format or Width/aspect ratio-speed rating-Tire Construction-Rim size format.

Click Here For Tire Pressure Gauge

Alphanumeric system

This is the standard system used in the United States. The measurements are given in inches and the measurements are straight forward.

Let us look at this format used by Shinko on one of their touring tires; MT90 – 16.

  • M is used to denote that the tire is a motorcycle tire
  • T denotes the width of the tire. In this case you have to refer to a chart to find out the width dimensions. Shinko always provide a chart on the website, so you can easily access the reference chart online.
  • 90 denote the aspect ratio. In this case it is 90%
  • 16 denote the size of the rim.

Click Here For Tire Pressure Gauge

There are 3 key differences between the Metric reading and the Alpha reading:

  • A· The format of alpha readings always starts with letter “M”
  • A· The width of the tire is denoted by a letter
  • A· The speed rating is usually preceded by letter “S”

The wheel construction is denoted by letter “B” otherwise it is assumed to be bias-ply.

Standard Inch System

This is an outdated system and is only found in classic motorcycle. It is usually given in inches, hence the name Standard Inch measurement system. The aspect ratio of these tires is 100%; and it may or may not be indicated. Another thing to note is that these tires are not belted and are of bias-ply construction.
An example is 3.25H-19

  • 3.25 symbolizes the width,
  • H symbolizes the speed rating, and
  • 19 symbolizes the rim diameter in inches

The aspect ratio, though not indicated, is 100% meaning the height of the tire is 100% the width of the tire
Low Profile Inch System

Click Here For Tire Pressure Gauge

This is almost similar to the standard system; the difference is that the aspect ratio is 82% instead of 100%. However, on some tires the aspect ratio may be specified as 85%. This system is no longer in use.

Next time you are out shopping for new tires, make sure you have the right size now that you have the readings explained to you. If you are looking for some motorcycle parts for Harley Davidson, we recommend checking  Viking Bags online store.

For All Motorbike Tires

Click Here For Tire Prices

Making Sense of Motorcycle Tire Sizes

Untitled Document

The most obvious piece of information is the big numbers and letters that usually look like this – 130/90 17, or MT90 17.

These numbers are a metric designation that indicates the size of the tire and the rim that tyre is designed to go on. The question is what do those numbers actually mean?

Let's start with the first series of numbers, 130/90 17 which in this case are a metric designation. This is the most popular nomenclature used in the motorcycle tire sizing world today. What do those numbers actually mean?

THE FIRST NUMBER – WIDTH

The 130 indicates the width of the tire in millimeters. This is measured as a straight line through the tyre from one edge of the tire's tread to the other edge.

THE SECOND NUMBER – ASPECT RATIO

The second number, the 90, represents how tall a motorcycle tire is in relationship to its width. This is the aspect ratio between the tire's width and its height indicated as a percentage. In simple terms this means the larger this number is, the taller the tyre will be. In the example the tyre is 90 percent as tall as its width which we could calculate to be 117mm.

THE THIRD NUMBER – RIM SIZE

The last number, 17, refers to the tire's rim diameter expressed in inches.

Inches

The width on some tires may be expressed in inches. In those cases the aspect ratio is usually not included.

Alphanumeric

An alphanumeric designation such as MT90 17, represents the same tire size as 130/90 17. It's just expressed in a different way. M means the tire is for motorcycle use, T is the tire width code, 90 is the aspect ratio and 17 is the rim diameter.

You'll notice the tables do not go any further than 150/90 tyre sizes. Here's why.

The alpha numeric method of tire sizing is older than the metric system. Way back when … motorcycle tires didn't get much larger than an MV85 which is equivalent to a width of 150mm. Modern tires larger than 150mm wide now only carry the metric size designation.

Front
INCHMETRICALPHANUMERIC
2.50/2.75 80/90 MH90
2.75/3.00 90/90 MJ90
3.25/3.50 100/90 MM90
4.00 110/90 MN90
4.25/4.50 120/80 MR85
4.25/4.50 120/90 MR90
5. 00/5.10 130/90 MT90

Rear
INCHMETRICALPHANUMERIC
4.00/4.50 110/90 MN90
4.50/4.75 120/80 MP85
4.50/4.75 120/90 MP90
5.00/5.10 130/90 MT90
5.50/6.00 140/90 MU90
6.00/6.25 150/80 MV85
6. 00/6.25 150/90 MV90

 


It's likely you'll find other letters mixed in within these motorcycle tire sizing numbers. They'll look like: 120/70ZR17 or 170/60R 17V, or even in other combinations. The two extra letters designate the tire's speed rating and construction.

Construction

The letter R or B indicates the construction used to create the casing of the motorcycle tire. An R stands for radial construction and a B indicates the casing has a belted bias.

Speed Rating

The other letter refers to the speed rating and indicates the maximum speed a motorcycle tire can sustain under its recommended load capacity. For example, U is indicates a maximum speed of 200 kmh / 124 mph.

In the examples the Z and the V are both speed rating indicators.

 

SPEED RATING MAX SPEED – MPH MAX SPEED – KPH
J Type 62 100
N Type 87 140
Q Type 99 160
S Type 112 180
T Type 118 190
U Type 124 200
H Type 130 210
V Type 149 240
W Type 168 270
Y Type 186 300
Z Type Over 149 Over 240

table with all tire sizes


  • Introduction

  • How to decipher the marking of motorcycle tires

  • Correspondence table for metric and inch tire marking systems

  • Conclusion


Motorcycle tires are impossible to choose correctly if you do not understand their sizes. Otherwise, at best, you risk bringing just a useless piece of rubber from the store. To determine the sizes, we have prepared a short decoding method and a comparison table of tire dimensions.

Any motor rubber has a sea of ​​​​information on the sidewall about the properties, purpose and, of course, size. We need to figure it out, and then compare the readings with the table. You can learn more about motorcycle tire labeling in our previous article.

As a rule, the main marking on the side of the tire looks like this: 120/80 R16 59S. This is the so-called metric marking. Let's understand it in more detail:

  • 120 - profile width from edge to edge of the tread, expressed in millimeters.

  • 80 - profile height, expressed as a percentage.

  • R - radial type of construction.

  • 16 - diameter of the landing area. This indicator should correspond to the same diameter of the rim on which the tire will be put on.

  • 59 - load index, or the maximum weight that the tire can withstand without loss of performance. We are looking for it in the table:


Tire load index

40

140

53

206

66

300

79

437

41

145

54

212

67

307

80

450

42

150

55

218

68

315

81

462

43

155

56

224

69

325

82

475

44

160

57

230

70

335

83

487

45

165

58

236

71

345

84

500

46

170

59

243

72

355

85

515

47

175

60

250

73

365

86

530

48

180

61

257

74

375

87

545

49

185

62

265

75

387

88

560

50

190

63

272

76

400

89

580

51

195

64

280

77

412

90

600

52

200

65

290

78

425

91

615


S is an index of the speed at which the bike can move without losing ride stability, grip and other useful tire characteristics. The value is also in a special table:

The models in the top are arranged in terms of price / quality ratio. In the process of writing it, we were guided by the reviews of amateur bikers, professional tests, and were also guided by our own subjective opinion and many years of experience with tires.

Speed ​​index

Maximum speed, km/h

A

40

B

50

C

60

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

W

270

Y

300

VR

>210

ZR

>240

(W)

>270

Z

>300


This method of marking tires is followed by most manufacturers, but there are those who prefer alternative types, where the dimensions are indicated in inches. For example, this one is 3.25H-19. Everything is simple here: 3.25 is the tire width expressed in inches, H is the speed index, 19 is the bore diameter.

Sometimes an inch designation can be used instead of the usual millimeter, for example, like this: 4.60/80 R16.

There is a rather rare alpha system created mainly for sports tourists. For example, this type of MM90S-16, where: MM - profile width in inches (3.75), 90 - profile height in percent; S - speed index, 16 - diameter of the landing rim of the tire.

Marking alpha

Width in inches

MG

2.75

MH

3.00

MJ

3.25

ML

3.50

MM

3.75

MN

4.00

MP

4. 25

MR

4.50

MS

4.75

MT

5.00

MU

5.50

MV

6.00


To make it easier for you to determine what the inch size corresponds to in the metric system and vice versa, we have prepared a comparison table for you.

Tire size in.

Load index

Permissible rim width, inch.

Tire size

Alpha

Metric

Standard

Reinforced.

100

90

80

2. 75-16

40

46

1.50-1.85

MH 90-16

80/100-16

80/90-16

90/80-16

3.00-16

40

48

1.60-2.15

MH 90-16

90/100-16

90/90-16

100/80-16

3.25-16

48

55

1.85-2.50

MJ 90-16

100/100-16

100/90-16

110/80-16

3.50-16

52

58

1.85-2.50

ML 90-16

100/100-16

100/90-16

110/80-16

4.60-16

58

59

1. 85-3.00

MM 90-16

100/100-16

110/90-16

120/80-16

2.75-17

41

47

1.50-1.85

MH 90-17

80/100-17

80/90-17

90/80-17

3.00-17

41

50

1.60-2.15

MH 90-17

90/100-17

90/90-17

100/80-17

4.50-17

50

67

2.15-3.00

MR 90-17

110/100-17

130/90-17

140/80-17

4.60-17

50

62

1. 85-3.00

MS 90-17

100/100-17

110/90-17

120/80-17

5.10-17

50

67

2.50-3.50

MT 90-17

110/100-17

130/90-17

140/80-17

2.75-18

42

48

1.50-1.85

MH 90-18

80/100-18

80/90-18

90/80-18

3.00-18

47

52

1.60-2.15

MH 90-18

90/100-18

90/90-18

100/80-18

3.25-18

52

59

1. 85-2.50

MJ 90-18

100/100-18

100/90-18

110/80-18

3.50-18

56

62

1.85-2.50

ML 90-18

100/100-18

100/90-18

110/80-18

3.60-18

51

62

1.85-2.50

MH 90-18

100/100-18

90/90-18

100/80-18

4.00-18

64

69

2.15-3.00

MN 90-18

110/100-18

120/90-18

130/80-18

4.10-18

60

69

1.85-3.00

ML 90-18

100/100-18

100/90-18

110/80-18

4. 25/85-18

64

69

1.85-3.00

MM 90-18

110/100-18

110/90-18

120/80-18

4.25-18

66

69

2.15-3.00

ML 90-18

110/100-18

120/90-18

130/80-18

4.60-18

63

69

1.85-3.00

MR 90-18

110/100-18

120/90-18

130/80-18

3.00-19

49

54

1.60-2.15

MH 90-19

90/100-19

90/90-19

100/80-19

3. 25-19

54

54

1.85-2.50

MJ 90-19

100/100-19

100/90-19

110/80-19

3.50-19

54

57

1.85-2.50

ML 90-19

100/100-19

100/90-19

110/80-19

3.60-19

52

54

1.85-2.50

MH 90-19

100/100-19

90/90-19

100/80-19

2.75-21

45

54

1.50-1.85

MH 90-21

80/100-21

80/90-21

90/80-21

3. 00-21

51

57

1.60-2.15

MH 90-21

90/100-21

90/90-21

100/80-21


Keep this chart for yourself and you will always have data on how to determine the size of motorcycle tires. In the BlackTyres online store, the selection of new clothes will be much faster and easier, because you can choose tires according to the model and size of the wheels of your bike. Just sort them using filters and choose your favorite tires.

Tire size chart and abbreviations maxdrive.com.ua

Tire size in inches Tire size metric
100 90 80
2. 75 80/100 80/90 90/80
3.00 90/100 90/90 100/80
3.25 100/100 100/90 110/80
3.50 100/100 100/90 110/80
3.60 100/100 100/90 100/80
4.00 110/100 100/90 110/80
4.10 100/100 110/90 120/80
4.25/85 110/100 120/90 130/80
4.50 110/100 110/90 120/80
4. 60 100/100 120/90 130/80
5.10 110/100 130/90 140/80

Explanation of rubber marking abbreviations:
120/70 Z 12 m/c (58W)

  • 120 - Tire width in mm
  • 70 - Profile height in % of tire width
  • Z - Permissible speed index
  • 12 - Rim diameter in inches
  • M/C - For motorcycles or scooters
  • 58 - Load index
  • W - Index of permissible speed at maximum load

Maximum speed
MPH km/h
V 149 240
(V) over 149 over 240
W 168 270
(W) over 168 over 270
Z over 149 over 240
Y 186 300

Tire load index
40 140 53 206 66 300 79 437
41 145 54 212 67 307 80 450
42 150 55 218 68 315 81 462
43 155 56 224 69 325 82 475
44 160 57 230 70 335 83 487
45 165 58 236 71 345 84 500
46 170 59 243 72 355 85 515
47 175 60 250 73 365 86 530
48 180 61 257 74 375 87 545
49 185 62 265 75 387 88 560
50 190 63 272 76 400 89 580
51 195 64 280 77 412 90 600
52 200 65 290 78 425 91 615

Dimension conversion
bar psi Bar psi Bar psi
1. 2 17 1.9 28 2.6 38
1.3 19 2.0 29 2.7 39
1.4 20 2.1 31 2.8 40
1.5 22 2.2 32 2.9 42
1.6 23 2.3 34 3.0 44
1. 7 25 2.4 35 3.1 45
1.8 26 2.5 36 3.2 46

Rim section height. Motorcycle tire width. Rim width. Disc width
Rim width, inches Tire width, mm
6.50 200
6.25 200
6.00 180 190 200
5. 5 180 190

Tire profile height 60, 65 and 70%
Rim width, inches Bar width mm
6.50 230
6.25 200 230
6.00 200 230
5.50 170 180 200
5.00 160 170 180
4. 50 140 150 160 170
4.25 140 150 160 170
4.00 130 140 150
3.75 120 130 140
3.20 120 130
3.00 110

Tire profile height 80 and 90%
Rim width.

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