What do the various size specifications on bicycle tyres mean?

Nowadays, bicycle tyre sizes are all marked according to ETRTO (European Tyre and Rim Technical Organization) standard. However, older English and French tire size dimensions are still used as well.

The ETRTO size specification 37-622 indicates the width of 37 mm and the tire inner diameter of 622 mm. This dimension is clear and allows a precise classification of the rim size.

The inch marking (e.g. 28 x 1.40) states the approximate outer diameter (28 inches) and the tire width (1.40 inches). Another inch marking is 28 x 1 5/8 x 1 3/8 (approximate outer diameter x tyre height x tyre width); it is also common.

Inch sizes are not precise and lack accuracy. For example, diameters 559 mm (MTB), 571 mm (Triathlon) and 590 mm (Touring) are all classified as 26 inch. Tyres with diameters 622 mm and 635 mm are both classified as 28 inch. Oddly enough, tyres with an inner diameter of 630 mm are classified as 27 inch.

These classifications originate from the time of tyre brakes. In those days, the exact outer diameter of the tyre was defined by the brake. Depending on tyre width, various standards for the inner diameter applied.

Inch dimensions are widely used in both MTB sport and English language countries. Therefore, we will continue to use these specifications for all tyres. But only in decimal form, e.g. 26 x 2.25. Experience tells us that nowadays very few users are familiar with the classical fractional inch dimensions, such as 28 x 1 5/8 x 1 3/8.

When the 29 inch MTB tyre size was introduced a few years ago, it had the same inner diameter of 622 mm, known as 28 inch in Europe.

The latest tyre size is 27.5 inches. This tyre size is favored for MTBs which are too small for the very big 29 inch wheels, in order to benefit from the advantages of bigger diameters. This is the case, for example, with bicycles having a very long suspension travel or very small frame sizes. 27.5 inch tyres have an inner diameter of 584 mm and are identical with the old French size marking 650B.

French size markings (e.g. 700 x 35C) give the approximate tyre outer diameter (700 mm) and width (35 mm). The letter at the end indicates the inner diameter of the tyre. In this case, C stands for 622 mm. French size markings are not used for all tyre sizes, so, for example, it is not used for MTB sizes.

 

  ETRTO Inches French
Size marking 37-622

28 x 1.40

28 x 1 5⁄8 x 1 3⁄8

700 x 35C
Outer diameter - ca. 28 inch ca. 700 mm
Inner diameter 622 mm - -
Tyre width ca. 37 mm

ca. 1 3⁄8 inch

bzw. 1.40 inch

ca. 35 mm
Tyre height -

ca. 1 5⁄8 inch

-
How many tyre sizes are there?

The following list shows all common tyre sizes. For virtually every tyre size, you should be able to find a corresponding ETRTO-size in this list.

The current Schwalbe sizes and markings are given in bold. We have tried to list in addition all tyre sizes which are currently used on the market or which were used in the past. These classical fractional size indications are also often engraved on old Schwalbe tyres. Sometimes, you still find them on current models which have already been available for quite a long time.

 

 

  ETRTO Inch French

12"

47-203 12 x 1.75  
    12 x 1.90  
    12 ½ x 1.75  
    12 ½ x 1.90  
  50-203 12 x 2.00  
  54-203 12 x 1.95  
  57-203 12 ½ x 2 ¼  
  62-203 12 ½ x 2 ¼  

14"

47-254 14 x 1.75  
    14 x 1.90  
  50-254 14 x 2.00  
  40-279 14 x 1 ½ 350 x 38B
  37-288

14 x 1 38

350 x 35A
   

14 x 1 58 x 1 38

 
  40-288

14 x 1 58

350 x 38A
  44-288

14 x 1 58 x 1 38

350 x 42A
  47-288 14 x 1.75  
  32-298 14 x 1 ¼ 350 x 32A

16"

40-305 16 x 1.50  
  47-305 16 x 1.75  
    16 x 1.90  
  50-305 16 x 2.00  
  54-305 16 x 1.95  
    16 x 2.00  
  57-305 16 x 2.125  
  40-330 16 x 1 ½ 400 x 38B
  28-340   400 x 30A
  32-340

16 x 1 38 x 1 14

400 x 32A
  37-340

16 x 1 38

400 x 35A
  44-340

16 x 1 58

 
  28-349

16 x 1 18

 
  30-349 16 x 1.20  
  32-349 16 x 1 ¼  

 

  16 x 1.25  
  35-349 16 x 1.35  
  37-349

16 x 1 38

 

17"

32-357 17 x 1 ¼  
  32-369 17 x 1 ¼  

18"

28-355

18 x 1 18

 
  32-355 18 x 1.25  
  35-355 18 x 1.35  
  40-355 18 x 1.50  
  42-355 18 x 1.60  
  47-355 18 x 1.75  
    18 x 1.90  
  50-355 18 x 2.00  
  37-387 18 x 1 ½  
  28-390

18 x 1 18

450 x 28A
  37-390

18 x 1 38

450 x 35A
  55-390   450 x 55A
  57-390   450 x 55A
  37-400

18 x 1 38

 

20"

54-400 20 x 2 x 1 ¾  
  23-406 20 x 0.90  
  25-406 20 x 1.00  
  28-406 20 x 1.10  
   

20 x 1 18

 
  32-406 20 x 1.25  
  35-406 20 x 1.35  
  37-406 20 x 1.40  
   

20 x 1 38

 
  40-406 20 x 1.50  
  42-406 20 x 1.60  
  44-406 20 x 1.50  
  44-406 20 x 1.625  
  47-406 20 x 1.75  
  47-406 20 x 1.90  
  50-406 20 x 2.00  
  54-406 20 x 2.10  
    20 x 2.00  
  55-406 20 x 2.15  
  57-406 20 x 2.25  
    20 x 2.125  
  60-406 20 x 2.35  
  54-428 20 x 2.00  
  40-432 20 x 1 ½  
  37-438

20 x 1 38

 
  40-438

20 x 1 38 x 1 ½

 
  28-440   500 x 28A
  37-440   500 x 35A
  40-440 20 x 1 ½ NL 500 x 38A
  23-451 20 x 0.90  
   

20 x 78

 
  25-451 20 x 1.00  
  28-451

20 x 1 18

 
  37-451

20 x 1 38 B.S.

 

22"

44-457 22 x 1.75  
  44-484

22 x 1 58 x 1 ½

 
  25-489 22 x 1.00  
  37-489

22 x 1 3⁄8 NL

 
  40-489

22 x 1 38 x 1 ½

 
  50-489 22 x 2.00  
  28-490   550 x 28A
  32-490

22 x 1 38 x 1 14

550 x 32A
  37-490

22 x 1 38

550 x 35A
  47-498

22 x 1 38 x 1 14

 
  25-501 22 x 1.00 B.S.  
  32-501 22 x 1 ¼  
  37-501

22 x 1 38

 

24"

40-507 24 x 1.50  
  44-507 24 x 1.625  
    24 x 1.75  
  47-507 24 x 1.75  
    24 x 1.85  
    24 x 1.90  
  50-507 24 x 2.00  
    24 x 1.90  
    24 x 2.125  
  54-507 24 x 2.10  
  55-507 24 x 2.15  
  57-507 24 x 2.25  
    24 x 2.125  
  60-507 24 x 2.35  
  62-507 24 x 2.40  
  23-520 24 x 0.90  
   

24 x 78

 
  44-531

24 x 1 58 x 1 12

 
  40-534 24 x 1 ½  
  20-540 24 x ¾  
  23-540 24 x 0.90  
   

24 x 78

 
  25-540 24 x 1.00  
  30-540 24 x 1.20  
  32-540

24 x 1 38 x 1 14

 
  37-540

24 x 1 38

 
  40-540

24 x 1 38 x 1 12

 
  22-541    
  25-541   600 x 25A
  28-541   600 x 28A
  32-541

24 x 1 38 x 1 14 NL

600 x 32A
  37-541   600 x 35A
  ETRTO Inch French

25"

57-520 25 x 2.25  

26"

20-559

26 x 34

 
  23-559 26 x 0.90  
   

26 x 78

 
  25-559 26 x 1.00  
  28-559 26 x 1.10  
  30-559 26 x 1.20  
  32-559 26 x 1.25  
  35-559 26 x 1.35  
  37-559 26 x 1.40  
   

26 x 1 58 x 1 38

 
  40-559 26 x 1.50  
  42-559 26 x 1.60  
  44-559 26 x 1.625  
  44-559 26 x 1.75  
  47-559 26 x 1.75  
    26 x 1.80  
    26 x 1.85  
    26 x 1.90  
  50-559 26 x 2.00  
    26 x 1.90  
    26 x 1.95  
  54-559 26 x 2.10  
    26 x 1.95  
    26 x 2.125  
  57-559 26 x 2.25  
    26 x 2.125  
    26 x 2.20  
  60-559 26 x 2.35  
  62-559 26 x 2.40  
    26 x 2.50  
  64-559 26 x 2.50  
  65-559 26 x 2.60  
  70-559 26 x 2.75  
  75-559 26 x 3.00  
  95-559 26 x 3.70  
    26 x 3.80  
  100-559 26 x 4.00  
  115-559 26 x 4.50  
  120-559 26 x 4.80  
  20-571

26 x 34

 
  23-571

26 x 78

650 x 23C
  40-571 26 x 1 ½ CS 650 x 38C
   

26 x 1 38 x 1 12 NL

 
  47-571 26 x 1 ¾ 650 x 45C
      650 CS Confort
  54-571 26 x 2 x 1 ¾ 650 x 50C
  20-590 26 x ¾ 650 x 20A
  25-590 26 x 1.00 650 x 25A
  28-590

26 x 1 38 x 1 18

650 x 28A
  32-590

26 x 1 38 x 1 ¼

650 x 32A
  37-590

26 x 1 38

650 x 35A
  40-590 26 x 1.50 650 x 38A
   

26 x 1 38 x 1 ½

 
  42-590

26 x 1 58

650 x 40A
  32-597

26 x 1 14

 

27"

40-609 27 x 1 ½  
  20-630 27 x ¾  
  22-630

27 x 78

 
  25-630 27 x 1.00  
   

27 x 1 116

 
  28-630

27 x 1 18

 
  32-630 27 x 1 ¼  
  35-630

27 x 1 38

 

27.5"

28-584

26 x 1 18 x 1 12

650 x 28B
  32-584   650 x 32B
  35-584 27.5 x 1.35 650B
   

26 x 1 38 x 1 12

650 x 35B
  37-584 27.5 x 1.40 650B
   

26 x 1 12 x 1 38

650 x 35B
     

650 Standard

  40-584 27.5 x 1.50 650B
   

26 x 1 58 x 1 12

650 x 38B
  44-584 27.5 x 1.65 650B
   

26 x 1 58 x 1 22

650 x 42B
     

650B

Semi-Confort

      650B ½ Ballon
  47-584 27.5 x 1.75 650B
  50-584 27.5 x 2.00 650B
  54-584 27.5 x 2.10 650B
    26 x 1 ½ x 2  
  57-584 27.5 x 2.25 650B

 

60-584 27.5 x 2.35 650B
  62-584 27.5 x 2.40 650B
  64-584 27.5 x 2.50 650B
  65-584 27.5 x 2.60 650B
  70-584 27.5 x 2.75 650B
  74-584 27.5 x 2.90 650B
  75-584 27.5 x 3.00 650B

28"

18-622 28 x ¾ 700 x 18C
  19-622   700 x 19C
      700 x 19
  20-622 28 x ¾ 700 x 20C
  22-622

28 x 78

700 x 22C
      700 x 22
  23-622 28 x 0.90 700 x 23C
   

28 x 78

 
  24-622   700 x 24C
  25-622 28 x 1.00 700 x 25C
   

28 x 1 116

 
  26-622   700 x 26C
  28-622 28 x 1.10 700 x 28C
   

28 x 1 58 x 1 18

 
  30-622 28 x 1.20 700 x 30C
  32-622 28 x 1.25 700 x 32C
   

28 x 1 58 x 1 ¼

 
  33-622 28 x 1.30 700 x 33C
  35-622 28 x 1.35 700 x 35C
  37-622 28 x 1.40 700 x 35C
   

28 x 1 58 x 1 38

 
  40-622 28 x 1.50 700 x 38C
   

28 x 1 58 x 1 ½

 
  42-622 28 x 1.60 700 x 40C
  44-622 28 x 1.625 700 x 42C
  47-622 28 x 1.75 700 x 45C
  50-622 28 x 2.00  
    29 x 2.00  
    28 x 1.90  
  55-622 28 x 2.15  
    29 x 2.15  
  60-622 28 x 2.35  
    29 x 2.35  
  32-635

28 x 1 ½ x 1 18

770 x 28B
      700 x 28B
      700B Course
  40-635 28 x 1 ½ 700 x 38B
   

28 x 1 ½ x 1 58

700B Standard

  44-635

28 x 1 58 x 1 ½

700 x 42B
  28-642

28 x 1 58 x 1 ½

700 x 28A
  37-642

28 x 1 38

700 x 35A

29"

50-622 29 x 2.00  
    28 x 2.00  
  54-622 29 x 2.10  
    28 x 2.10  
  55-622 29 x 2.15  
    28 x 2.15  
  57-622 29 x 2.25  
  60-622 29 x 2.35  
    28 x 2.35  
  75-622 29 x 3.00  

28 inch and 29 inch tyres have the same inner diameter of 622 mm and can be fitted on the same rims.

What is actually the difference between 28 and 29 inches?

The silliest answer to this question would be to say that the difference is exactly 1 inch. Another answer would be: There is no difference.

Both tyre sizes have the same inner diameter of 622 mm and can therefore be fitted on the same rims.

In Europe, 28 inches is a traditional size for touring bicycles. In many countries it is even the most frequent tyre size used. In countries outside Europe the rim diameter of 622 mm is only rarely used. Bicycle travelers who want to buy spare tyres for a 28-inch touring bicycle anywhere in the world, can tell you a thing or two about it.

A few years ago 29 inch tyres were introduced as a new wheel size for mountain bikes in the US. The marking was created, as the MTB tyres are more voluminous and the outer diameter measures approximately 29 inches.

Both indications are, however, very imprecise. A less wide 28 inch tyre, e.g. with a tyre width of 23 mm, which is usual for a road bike, has in fact only an outer diameter of something more like 26 inches. In the case of a tyre width of 40 mm,
it is more or less correct that the outer diameter measures 28 inches. In the case of very wide tyres with 60 mm or more, the actual outer diameter measures almost 30 inches.

What are the advantages of the new wheel sizes 27.5 and 29 inches?

The new sizes are well established on the market and this is for good reason. The advantages of the large wheels outweigh the disadvantages. 29 inch wheels weigh a little more, are less maneuverable and possibly less stiff, but they roll clearly
faster on rough surfaces especially in the terrain. The contact surface is bigger which makes for a significantly better tyre grip.

There are, however, some bicycles which do not have enough clearance for a large 29 inch wheel, e.g. in the case of very small frame sizes and in particular bicycles with very long suspension travel. This is where the new wheel size 27.5 comes in.

Schwalbe will continue to offer all usual MTB tyres for all three diameters.