In modern cycling, the dogma of inflated tyres is long gone. From Tadej Pogačar to weekend mountain bikers - if you want to get to the finish line and over the mountains quickly and comfortably, you need to deflate your tyres.
"The motivation is high, the pressure is low - as low as my tyre pressure will be." With this sentence before the Tour of Flanders, Tadej Pogačar, the dominator of modern road cycling, summarised a trend that began some time ago but is now becoming increasingly clear. While amateur riders often still hop over the asphalt with 8 bar in their narrow 23 mm tyres, the professionals at the Tour de France now race through the finish line on 28-32 millimetre wide tyres with 5 to 6 bar. On rough surfaces, such as the cobblestone tracks of Paris-Roubaix, the pressure even drops to much lower values.
This is the provisional culmination of a development that began around 10 years ago. Knowing the physical principle (see below), we dared to increase the tyre width from 23 to 25 millimetres and reduce the pressure from around 8.5 to 10 bar (depending on system weight and surface) to 6.5 to 7.5 bar. The next step was reached in 2019/2020: 25-28 mm was now the measure of all things and the tyre was deflated by another bar. For around three years now, the width has stabilised at 28 to 30 mm and the air pressure at 4 to 5.5 bar. For the time being.
The physical principle
The old prejudice was that a hard tyre deforms less and therefore rolls more easily. This is true - but only on a perfectly smooth surface. The reality on the road is different. Every little bump, every pebble and every rough asphalt pore forces a hard tyre to lift the entire system (bike and rider) slightly. This vertical movement costs energy.
A tyre with lower pressure, on the other hand, acts as a suspension. It deforms (rolls) around the obstacle instead of travelling over it. The wheel runs more smoothly and energy losses are lower. In addition, the lower the pressure, the greater the traction: the contact area becomes wider, increasing grip when cornering and braking.
The air pressure depends on these factors
- Tyre width: A wider tyre requires significantly less pressure for the same suspension capacity with the same system weight (bike + rider + equipment).
- Inside rim width: Modern, wide rims support the tyre better, which often allows a lower pressure without the tyre becoming unstable.
- Poor road surface: The worse, i.e. more uneven, the road surface, the further you have to lower the pressure so that the tyre rolls around the obstacle accordingly.
- Tubeless: A tubeless set-up increases puncture protection against punctures. Tubeless tyres therefore allow you to reduce the pressure by approx. 0.5 bar without increasing rolling resistance - this is compensated for by the lack of a tube.
- Weight distribution: Road cyclists usually have a distribution of approx. 45% at the front and 55% at the rear. If you want to do it perfectly, you should run approx. 0.2-0.4 bar more at the rear than at the front.
- System weight: The heavier the overall system, the greater the deformation of the tyre. In order to keep the deformation constant with increasing system weight, the air pressure must be adjusted, i.e. increased.
Adjust the tyre pressure to the system weight
In order to keep the tyre deformation comparable with different weights, the tyre pressure must be adjusted in proportion to the total mass of the rider and bicycle. The total mass is calculated from the bike weight, rider weight and clothing or equipment. Around 10 kilos can be calculated for the bike and equipment. If you take a rider weight of 75 kilos, i.e. a system weight of 85 kilos, and a tyre pressure of 4.5 bar as a reference, the following example calculation shows how the tyre pressure must be increased with increasing system weight:
| Driver | System weight | Recommended tyre pressure |
| 75 kg | 85 kg | 4.5 bar |
| 80 kg | 90 kg | approx. 4.8 bar |
| 85 kg | 95 kg | approx. 5.0 bar |
Road bike: from the Tour stage to cobblestones
The standard in road cycling is currently 28 to 30 mm, and it is not uncommon for 32 mm wide tyres to be fitted. However, which width and pressure you ride depends not only on the factors mentioned above, but also on tactical considerations.
- Professional race (flat/mountain): On a normal Tour de France stage on good asphalt, the pros now ride exclusively tubeless, usually with 28 mm wide tyres, and the tyre pressure is usually around 4.8 bar (rear) at 75 kg body weight. On mountain stages, however, a little more pressure is often released to maximise grip on the fast descents.
- Classics like the Tour of Flanders: Steep climbs meet treacherous pavement here. Pogačar and his colleagues rely on 30 mm or 32 mm wide tyres here. The pressure drops to well below 4 bar in places. The aim: to protect the muscles from the gruelling and tiring vibrations.
- Everyman race: Here, puncture protection often comes before the last mill of performance. A pressure of around 5.5 to 6 bar at 28 mm width offers a good compromise (when using inner tubes).
Gravelbike: The border crossers
Graveling is the discipline of compromise. It should roll on tarmac and not lack grip and comfort off-road. A typical 40 millimetre wide gravel tyre is run at between 2.0 and 3.0 bar.
- Lots of tarmac: If you mainly commute on cycle paths, choose around 3.0 bar.
- Coarse gravel: Here, around 2.2 bar is ideal for a smooth ride.
Mountain bike: Millimetre work off-road
The search for the optimum tyre pressure for MTB is even more complex, as the individual MTB disciplines have very different requirements. The tyre widths are between 2.25 and 2.6 inches. The system weight of an E-MTB is around 10 kilos heavier than that of a non-motorised bike. There are also different tyre carcasses. The more stable the tyre, the lower the air pressure can be selected.
- Cross-Country (XC): The routes in the Cross Country World Cup have become increasingly rough and technically demanding in recent years. The demands on the material have changed accordingly. Professionals now ride 2.25 to 2.4 inch wide tyres on rims with a rim width of 28 to 30 mm.
Often only 1.4 to 1.7 bar is pumped into the tyres, depending on the route and rider weight. An optimum compromise is sought here between maximum traction and good rollover behaviour on the one hand and puncture protection on the other. - Enduro & Downhill: Very stable tyre carcasses are often used here, with the focus on cornering grip and braking traction. However, the tyre pressure must not be set too low - otherwise there will be a lack of stability in fast corners and compressions. In addition, tyres are ridden hard in the gravity range - if the air pressure is too low, there is a risk of damage to the rim in the event of punctures.
While only 1.5 bar is often used at the front, a little more (1.7 bar) is usually pumped up at the rear due to the risk of punctures. So-called "inserts" (foam rings in the tyre) are often used on downhill bikes, which allow the pressure to be lowered even further.
The expert tips: How to find your print
The pressure is individual. It depends not only on the system weight, tyre width and surface or area of use, but also on personal preferences and riding style.
The tyre pressure guide: Orientation values
Values are based on a reference rider weight of approx. 75 kg (system weight approx. 85-90 kg) and tubeless setup. When using inner tubes, add approx. 0.3 - 0.5 bar.
| Bike type | Field of application | Tyre width | Tyre pressure (orientation value) |
| Racing bike | Professional race asphalt | 28-30 mm | 4.4 / 4.8 bar |
| Racing bike | Classic (cobblestones) | 30-32 mm | 3.2 / 3.6 bar |
| Racing bike | Everyman / Tour | 28 mm | 5.5 / 6.0 bar |
| Gravel | All-round (gravel/asphalt) | 40 mm | 2.3 / 2.6 bar |
| Gravel | Technical terrain | 45 mm | 1.9 / 2.2 bar |
| MTB | Cross-Country (XC) | 2.25" (57 mm) | 1.5 / 1.7 bar |
| MTB | Tour / Alpine trails | 2.4" (60 mm) | 1.6 / 1.8 bar |
| MTB | Enduro / Downhill | 2.5" (64 mm) | 1.5 / 1.7 bar |
Conclusion
Tadej Pogačar's statement illustrates the change in cycling: if you ride "hard" today, you lose comfort, grip and ultimately time. This applies not only to professional road cycling, but also to other types of cycling such as gravel and MTB. However, tyre pressure is not a static number, it is a dynamic tool that depends on many factors and must be designed individually.
Josh Welz
Editor-in-Chief
