In fact, mountain biking encompasses a number of different sports, each with its own specific riding characteristics and materials. There’s a wide choice of bike models, tire sizes and tubes. So it’s impossible to define one formula that will work for all of them.
The following tables contain indicative values in bar and psi for tyre inflation. These values are based on a rider with a body weight of 75 kg. For each additional kilogram of weight (including luggage), the pressure can be increased by 1%, and decreased in the same proportions if the weight is reduced. Starting from this initial value, you can get closer and closer to the optimum pressure by taking other factors, such as terrain, into account.
GUIDE VALUES FOR CERTAIN MOUNTAIN BIKE TYRE WIDTHS IN MM
| TYRE WIDTH (MM) | ATMOSPHERIC PRESSURE (BAR) |
|---|---|
| 20 mm | 9,0 bar |
| 23 mm | 8,0 bar |
| 25 mm | 7,0 bar |
| 28 mm | 6,0 bar |
| 30 mm | 5,5 bar |
| 32 mm | 5,0 bar |
| 35 mm | 4,5 bar |
| 37 mm | 4,5 bar |
| 40 mm | 4,0 bar |
| 42 mm | 4,0 bar |
| 44 mm | 3,5 bar |
| 47 mm | 3,5 bar |
| 50 mm | 3,0 bar |
| 54 mm | 2,5 bar |
| 57 mm | 2,2 bar |
| 60 mm | 2,0 bar |
GUIDE VALUES FOR CERTAIN MOUNTAIN BIKE TYRE WIDTHS IN INCHES
| TYRE WIDTH (INCHES) | ATMOSPHERIC PRESSURE (BAR) | PRESSURE ON BIS AND PSI |
|---|---|---|
| 24 x 1.5 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 24 x 1.625 pouce | 2.5 - 2.5 bar | 36 bis 36 psi |
| 24 x 1.75 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 24 x 1.85 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 24 x 1.90 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 24 x 2 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 24 x 2.1 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 24 x 2.125 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 26 x 0.90 pouce | 4.5 - 5.5 bar | 65 bis 80 psi |
| 26 x 1 pouce | 4.0 - 5.0 bar | 58 bis 73 psi |
| 26 x 1.1 pouce | 3.5 - 4.5 bar | 51 bis 65 psi |
| 26 x 1.2 pouce | 3.0 - 4.0 bar | 44 bis 58 psi |
| 26 x 1.25 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 26 x 1.35 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 26 x 1.4 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 26 x 1.5 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 26 x 1.6 pouce | 2.2 - 3.5 bar | 32 bis 51 psi |
| 26 x 1.625 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 26 x 1.75 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 26 x 1.8 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 26 x 1.85 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 26 x 1.9 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 26 x 1.95 pouce | 2.0 - 2.5 bar | 29 bis 36 psi |
| 26 x 2 pouce | 1.8 - 2.2 bar | 26 bis 32 psi |
| 26 x 2.1 pouce | 1.8 - 2.2 bar | 26 bis 32 psi |
| 26 x 2.125 pouce | 1.8 - 2.2 bar | 26 bis 32 psi |
| 26 x 2.25 pouce | 1.8 - 2.2 bar | 26 bis 32 psi |
| 26 x 2.35 pouce | 1.8 - 2.2 bar | 26 bis 32 psi |
| 26 x 2.4 pouce | 1.8 - 2.2 bar | 26 bis 32 psi |
| 26 x 2.5 pouce | 1.6 - 2.2 bar | 23 bis 32 psi |
| 26 x 2.75 pouce | 1.6 - 2.0 bar | 23 bis 29 psi |
| 26 x 3 pouce | 1.6 - 2.0 bar | 23 bis 29 psi |
| 27.5 x 1.35 pouce | 2.8 - 5.0 bar | 41 bis 73 psi |
| 27.5 x 1.4 pouce | 2.5 - 5.0 bar | 36 bis 73 psi |
| 27.5 x 1.5 pouce | 2.5 - 4.0 bar | 36 bis 58 psi |
| 27.5 x 1.6 pouce | 2.2 - 3.5 bar | 32 bis 51 psi |
| 27.5 x 1.65 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 27.5 x 1.75 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 27.5 x 2 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 27.5 x 2.1 pouce | 2.0 - 2.5 bar | 29 bis 36 psi |
| 27.5 x 2.25 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 27.5 x 2.35 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 27.5 x 2.4 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 27.5 x 2.6 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 27.5 x 2.75 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 27.5 x 2.9 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 27.5 x 3 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 28 x 0.9 pouce | 4.5 - 5.5 bar | 65 bis 80 psi |
| 28 x 1 pouce | 4.0 - 5.0 bar | 58 bis 73 psi |
| 28 x 1.1 pouce | 3.5 - 4.5 bar | 51 bis 65 psi |
| 28 x 1.2 pouce | 3.5 - 4.5 bar | 51 bis 65 psi |
| 28 x 1.25 pouce | 2.5 - 4.0 bar | 36 bis 58 psi |
| 28 x 1.3 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 28 x 1.35 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 28 x 1.4 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 28 x 1.5 pouce | 2.5 - 3.5 bar | 36 bis 51 psi |
| 28 x 1.6 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 28 x 1.625 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 28 x 1.75 pouce | 2.2 - 3.0 bar | 32 bis 44 psi |
| 28 x 1.9 pouce | 2.0 - 3.0 bar | 29 bis 44 psi |
| 28 x 1.95 pouce | 2.0 - 2.5 bar | 29 bis 36 psi |
| 28 x 2 pouce | 2.0 - 2.5 bar | 29 bis 36 psi |
| 28 x 2.15 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 28 x 2.35 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 29 x 2 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 29 x 2.1 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 29 x 2.15 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 29 x 2.25 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
| 29 x 2.35 pouce | 1.8 - 2.5 bar | 26 bis 36 psi |
HOW TO PROPERLY INFLATE A MOUNTAIN BIKE TYRE?
Here are the steps to follow to inflate a mountain bike tire to the optimum pressure:
- Enter the recommended values for your tire size here.
- Use the tips on this page to adjust these standards to your use.
- Get on your bike, test your settings and adjust according to how you feel.
WHY THE RIGHT PRESSURE IS SO IMPORTANT
The tyres are the only part of the machine that touches the road. That’s why the bike’s handling depends on the tyres more than anything else. But what is the right tyre pressure? The answer to this question is anything but simple, for a number of reasons. The type of tyre is just as important as its use, the choice of tube and the place where it’s used. The rider’s weight, whether light or heavy, also affects tire pressure; this is also the case when, for example, another load has to be carried. Answers from tyre manufacturers to various questions about tyre pressure. There are different tyre diameters, cross-sections and profiles. What’s more, each tire is optimized for a specific application.
When you’re looking for the right pressure, you need to keep in mind reducing rolling resistance, getting the best control, protecting the tyre from breaking and achieving a level of comfort, because ultimately every tyre also has factors that – heat. If you want to know the right pressure, you need to specify the exact use, based on a few guidelines and, above all, test many different pressures.
MOUNTAIN BIKE TYRE PRESSURE DEPENDS ON THE TYPE OF GROUND
A propos du goudron : Plus le pneu est gonflé et plus la pression est élevée, plus sa résistance est faible. Dans le monde naturel, c’est très différent. Des études ont montré que même sur des surfaces de gravier, la basse pression se poursuit avec un faible rebond.
As a general rule, large MTB tyres tolerate low pressures without damaging the wheel. However, pressure can be reduced to a certain extent, as other factors must be taken into account in addition to rotational resistance. These include grip, suspension and stability of both tyre and rim. So it’s important to strike the right balance: pressure as low as possible, but as high as necessary.
Even if some values are indicated on the tyre in its product documentation, it’s still important to test the pressure yourself. Heavier cyclists are advised to use tires with higher pressures, but this also depends on the ground and riding style.