Finding the correct tyre pressure for bicycles

Unit of tyre size?
Tyre measurements?

Recommended tyre pressure: bar (is equal to psi)

The values provided are for guidance only and apply for a rider with 75 kg body weight without baggage. We recommend approximately 1% more tyre pressure for each additional kilogram of weight. Guide values may fluctuate depending on tyre type and bike model.

Caution: Never surpass or undercut the limit values provided!

Why correct tyre pressure matters

The tyre is the only area where the bike comes into contact with the road. That is why it contributes more to the driving properties of a bike than any other component. What tyre pressure is correct? Because of the many factors involved, this question is not easy to answer. The tyre type plays as much a role as its purpose, the type of inner tube and the terrain, on which it will be used. A rider with a very low or very high body weight will impact the tyre pressure just as much, as if the bike will have to carry additional baggage.

The answers for the pressure question that come from a tyre manufacturer can vary greatly. You can have tyres in a variety of diameters, with different diameters and various profiles. Each individual tyre type is optimised for a particular purpose.

The aim when choosing tyre pressure is to minimise rolling resistance, get the best possible steering behaviour, protect the tyre against punctures and to have some degree of comfort, because after all: each tyre also has some cushioning properties. To find the correct tyre pressure, make sure to define the purpose of the tyre as precisely as possible, take note of the guide values provided and last but not least: go ahead and experiment a little.

Overview: Pressure for bike tyres
Low tyre pressure High tyre pressure
✓ More comfort
✓ More grip
✓ Less rolling resistance in rough terrain
✓ Less likelihood to have a puncture
✓ Less wear
✓ Less rolling resistance on tarmac

Guide values for optimal tyre pressure

Inscription on the tyre flank

Inscription of the minimum and maximum permissible tyre pressure on tyre flank
Inscription of the minimum and maximum permissible tyre pressure

Every bike tyre comes with an inscription of the minimum and maximum permissible tyre pressure on its flank. These values, however, are only rough guide values that should not be surpassed or undercut when riding the bike. The rubber mantle of the tyre could be damaged if the actual tyre pressure is below the stated range, because the tyre would be subjected to excessive stresses and the flanks would crack. A pressure value above the maximum stated value, on the other hand, would stretch - and in a worst case scenario - possibly burst the tire. The optimal pressure value is therefore somewhere between these two limit values. The trick is to find exactly what that value is.

Guide values for specific tyre widths in mm

The table contains guide values for the tyre pressure in bar for various tyre types. The values are based on a rider with 75 kg body weight. tyre pressure can be increased by around 1% per KG additional weight (also for baggage) and can be relevantly reduced for less weight. Using this base value and taking into consideration other factors like terrain, you can then approximate the optimal value bit by bit.

Caution: The limit values stated on the tyre flank must not be surpassed or undercut!

Chart: Tyre pressure guide values
Tyre width (mm) Tyre pressure (bar)
20 9,0
23 8,0
25 7,0
28 6,0
30 5,5
32 5,0
35 4,5
37 4,5
40 4,0
42 4,0
44 3,5
47 3,5
50 3,0
54 2,5
57 2,2
60 2,0

Impact of the terrain

The type of terrain on which the bike will travel has the greatest impact on choosing the correct tyre pressure. Will the bike be used mostly on roads? Or is it supposed to travel on dirt tracks? A special topic here are single purpose mountain bikes, because the topic of tyre pressure is a lot more complicated with them.

On smooth road surfaces like tarmac, choosing the right tyre pressure is comparatively easy. Good roads without potholes mean a tyre pressure at the upper end of the limit values provided on the tyre flank. Rolling resistance will be reduced and the bike will run smoothly, with plenty of propulsion. Once you have to factor in potholes or ridges like the edges of pavement - as is often the case in daily traffic - tyre pressure should be relevantly reduced. Every tyre has cushioning properties, which come more or less to the fore depending on tyre pressure. Unfortunately, lower tyre pressure also means a higher rolling resistance on smooth road surfaces.

Less traction with high tyre pressure
Less grip with high tyre pressure
More traction with lower tyre pressure
More grip with lower tyre pressure

Gravel tracks can further complicate things. Depending on the grit size of the gravel, low tyre pressure may significantly increase comfort for the rider, because the tyre is soft enough to absorb surface impact. However, the lower the tyre pressure, the higher the risk of a puncture, e.g. when driving through a pothole and a sharp stone penetrates the mantle and perforates the inner tube.

If your tour will include a lot of gravel paths, then using a lower tyre pressure is recommended. If you do experience a lot of punctures that way, then you should increase pressure levels slowly, until there are no more punctures. Another negative factor with low tyre pressure is the increased rolling resistance on smooth tarmac. While the rolling resistance decreases on gravel at low tyre pressures, because gravel is simply deflected instead of rattled over, resistance increases on smooth ground, because the tyre is compressed more and therefore under a lot more strain.

Special case: Touring wheels

Touring wheels are very versatile, they can deal well with a great variety of surfaces. While many tours will take you along good, tarmacked bike lanes, others may take you across gravel tracks with pointy rocks. This type of bike tyre is no stranger to extreme cycling expeditions to the Himalayas or Iceland’s deserts.

Another issue to consider when selecting the correct tyre pressure is the load the tyres will have to carry. Not only the weight of the rider plays an important role, but very importantly: the weight of the baggage. On extended trekking tours complete with camping equipment and possibly food for several days, extra baggage can quickly come to over 20 kg. A tyre should still run easily, offer some comfort and master everything the terrain has to offer despite having to bear a high overall weight (rider + bike + baggage), without provoking problems.

Touring tyres also have to deal with a great variety of influencing factors. In the end, no rider will get around having to do extensive testing. The information provided by the tyre manufacturer can be a useful initial pointer in terms of what tyre pressure to start with. No two tours cover the same kind of terrain, which means tyre pressures should also differ.

Weight factor

The higher the system weight (bike + rider + baggage), the higher the tyre pressure should be. There are two reasons for that: On the one hand, the tyres are compressed more due to the higher weight and accordingly run less well and on the other, the risk of punctures increases in particular for the rear wheel. That is, of course, due to the fact that a large part of the system weight impacts on the rear wheel, as does the main weight of the baggage.

Tyre size factor

Touring wheels are available in a wide range of tyre types. From a 30 slick to trekking tyres and thicker balloon tyres or in some cases even fat bike tyres – the variety is huge and the tyre pressures vary accordingly. As a rule of thumb: The thinner the tire, the higher the pressure and vice versa. A thin road tyre would have 6-8 bar of pressure, much like a road bike (have a look at our tyre pressure calculator for road bikes), while for a fat bike tire, a pressure of 0.5 bar will suffice. These two extremes, however, represent only the upper and lower pressure limits; for standard trekking wheels, the most frequent choice would be a tyre pressure between 3 and 4 bar. The rear tyre will do well with 0.2-0.5 bar more pressure than the front tyre if there is a lot of weight on the back.

Minimising rolling resistance without provocating punctures

The trick in finding the correct tyre pressure for front and rear tyres is to minimise the rolling resistance, while at the same time maximising comfort and keeping the puncture risk as low as possible. A general rule says: The rougher the terrain, the lower the tyre pressure should be in order to keep the rolling resistance to a minimum. The tyre will then be able to shape itself around rocks, instead of having to roll over them. But be careful: When the tyre pressure gets too low, the risk of punctures increases immensely. On smooth road surfaces, the tyre pressure can be at the top end of what the manufacturer states on the tyre flank without any problem to minimise rolling resistance.

Sufficient tyre pressure will prevent punctures
Sufficient tyre pressure will prevent punctures
Punctures down to the rim with too little tyre pressure
Punctures down to the rim with too little tyre pressure

Designation systems for tyre sizes

The size of the bike tyre is not just important for finding the correct tyre pressure. Choosing the right tyre is difficult, because differing denomination systems are used when stating the size.

Traditional systems offer the outer diameter of the tyre in inches or millimetres and combine these measurements with the tyre width. Latest developments in the bike sector have downgraded the information to pure denomination classifications and often differ significantly from the actual measurements. In response, the ETRTO system, a new universal system, which is also used by the International Standardization Organisation (ISO) was introduced. It consists of the two components tyre width and inner tyre diameter, whereby the inner tyre diameter stated in millimetres (e.g. 622 mm) is the deciding component.

Tyre sizes in inches

One popular orientation measurement for specifying a tyre size is still the outer tyre diameter, which is stated in inches. The following table illustrates, which inch size is generally used for which bike type.

Popular tyre sizes in inches
Outer tyre diameter Use
24'' Kids bikes
26'' Mountain bikes, electric bikes
27'' Tyre size with little relevance
27,5'' Mountain bikes (marketing term for new French size 650B)
28'' Road bikes, city bikes, touring bikes
29'' Mountain bikes (new tyre size), cyclocross bikes

French system

The traditional French system is metric and consists of the two components outer tyre diameter and an ordinal system for stating the tyre width, from A for narrow to D for wide. The significance of the tyre width has been severely reduced because of the manufacture of narrow tyre sizes for rims that were originally only meant to be used with wide tyres.

Popular tyre sizes in the French system
700A 642 mm none
700B 635 mm Bar brakes touring bikes
700C 622 mm City bikes, hybrid bikes, 29er
700 D 587 mm older GT models
650 A 590 mm the same as 26 x 1 3/8
650 B 584 mm French city bikes, tandem bikes, touring bikes, late model mountain bikes
650 C 571 mm Triathlon bikes, time trial bikes, competition bikes for short-stature riders
600 A 540 mm European youth bikes, wheelchairs
550 A 490 mm European youth bikes
500 A 440 mm European youth bikes, folding bikes
450 A 390 mm European youth bikes
400 A 340 mm European youth bikes