What Does 40 622 Mean On A Bike Tire?

It is always important to know the right tire size for your bike in case you want to change your bike tires. Each tire size is very variable depending on the type of bike tire you are looking for, and depending on what type of bicycle you have.

In this article, you will get a guide on how to choose the right bike tire size for your bike and the type of bike tire you wish you would have known before buying a bicycle.

What Does 40 622 Mean On A Bike Tire?

What does 40 622 mean on a bike tire? The 40 means the inflated width in mm and the 622 means the internal diameter in mm. This dimension is clear and even allows a precise classification of the bicycle rim size.

It’s the international standard ISO-5775 for bicycle tire sizes. In brackets is the French size which is 700mm outer diameter x 38mm width and on the other hand, the Inch size which is 28 outer diameter x 1 5/8 height x 1 1/2 width.

What’s the widest tire you can put on a 700C wheel?

On a 700c rim, you can put a range of different widths. The standard for most road cycling over the past couple of decades is 23mm wide tires.

You might also see a 700x20c or even a 700x25c. On a cyclocross bicycle or 29-inch MTD (mountain bike), you could see tires wide such as 700x35c or even 700x58c

Bicycle tire widths accessible for the 700C/622mm size standard vary from 18-47mm, with well-known widths including 23, 25, and 28mm in the mix.

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The big-wheeled MTBs called 29ers also use this kind of size, and there are off-road tires up to a whopping 75mm wide. Here is the type of tire sizes you need to know as a rider

Type of tire sizes


32″ (ISO 686 mm) and 36″ (ISO 787 mm)

There are oversized bicycle tires but they are extremely unusual, custom-built frames for very tall riders tend to use 32″ or 36″ wheels.

There is a low possibility to find these kinds of sizes on production bikes, however, if you are over 6′ 6″ and you want for a bicycle that fits, custom-built might be the only one you are looking for.

Standard Full-Size Wheels

26″ Wheels (ISO 559 mm)

As we know that 26″ wheels have a long history in the bicycle industry. Almost 100 years ago it started as the standard for American-made cruisers and later became the most well-known MTB (mountain bike) wheel size and even remained on top for decades.

Old 26” cruiser wheels were the only bike wheels around that had wide enough bike tires for the demands of the off-road, when the world’s first MTBs were being fabricated by pioneers like Joe Breeze, Charlie Kelly, and Gary Fisher.

These standard wheels for MTBs are used on several high-performance folding bicycles. The actual ISO diameter of a traditional 26″ wheel is 559 mm.

The term ’26 inch’ doesn’t refer to the diameter of the bike wheel itself, but rather the approximate outside diameter of the tire that actually fits this wheel size.

27.5″ / 650b Wheels (ISO 584 mm)

Bicycle wheels with an ISO diameter of 584 mm were originally named 650b. In the 1960s, these kinds of wheels were first introduced on French touring bicycles.

Being a bit smaller than modern road bicycle wheels, their use persisted on small and extra-small road frames that could not accommodate a 700c wheel at all.

But the size is still called 650b when used on gravel or on-road bicycles. MTBs have been moving toward larger wheels in recent years.

When 650b was re-purposed for off-road it became called 27.5″ and when compared to the 26″ wheels that dominated the mountain bike world, 27.5″ wheels have several benefits such as:

  • A larger contact patch for more traction
  • The ability to roll over obstacles more easily
  • More rotational inertia to maintain momentum.

The Montague Paratrooper Highline and Paratrooper Elite are the first folding bicycles in the plant and they use 27.5″ wheels. The 650b wheel was adopted by mountain bikers and became 27.5″

29″ / 700c (ISO 622 mm)

These are the two more usual bike wheel sizes that are exactly the same. The standard modern road bicycle wheel has an ISO diameter of 622mm and is also referred to as 700c.

The name came from international tire sizes where the outside diameter would be about 700mm, and multiple rim sizes would be labeled 700a, 700b, 700c, and so on.

The 622 mm rim became the most familiar with narrow road tires. Nearly every adult bicycle in the plant made for use on pavement comes equipped with 700c wheels.

As we said above that the 650b wheel was adopted by mountain bikers and then became 27.5″. The 700c wheel has taken the MTB industry and become called 29″.

16″ Wheels (ISO 305 mm)

These types of wheels are most commonly found on children’s bikes, 16” wheels are small but you can find them on adult bicycles.

They are used on some adult folding bikes in order to offer a compact folded size.16” wheels are perfect for children just learning to stay upright.

16″ wheels are not good for rough or bumpy roads because they are the smaller wheels, the more they’ll be affected easily by small debris and rocks, or even potholes can swallow the whole wheel.

There is a big difference between riding with a 16′ wheel and a full-size adult bicycle you are used to. The turning radius and wheelbase are smaller and can result in sensitive steering.

Keep in mind that smaller wheels need larger gear ratios to get them turning fast enough and this makes hill climbs more difficult.

20″ Wheels (ISO 406 mm)

20″ wheels are the standard for BMX bicycles and the most common size for small whee folding bicycles.

They are loved by BMX riders for making flatland and aerial tricks simpler. They are better than 16″ wheels, however, the 20″ wheel will still be affected by rocks and obstacles, unlike larger standard wheel sizes.

Smaller wheels also need unique frame geometry and an extra-long handlebar stem in order to offer a normal upright position for the rider.

24″ Wheels (ISO 507 mm)

These types of bike wheels are a fairly uncommon size and are most likely to be found on junior MTBs, and also a handful of BMX “cruiser” models made for larger riders that want the same geometry and maneuverability of their 20″ counterparts.

What size tires do pro cyclists use?

Not long ago, the professional racing cyclists’ favorite tires were 19 to 23 mm tires, and regular cyclists like to follow the pros.

Now 20 teams are using 25mm tires for non-time trial stages, and the other two Specialized-sponsored teams are even using 26mm rubber.


In conclusion, bigger or smaller wheels on a bike are both good because, on smooth surfaces, small wheels have less aerodynamic drag because of a smaller frontal area.

Smaller wheels can be built lighter (therefore easier to propel uphill) and on the other hand, larger wheels theoretically offer slightly better rolling resistance (the effect of this is very small).