Inflating your mountain bike tyres: what's the right pressure?

From grip to performance and safety, your mountain bike's tyre pressure has a big impact on your ride. We show you how to make sure that your MTB tyres are inflated to the right pressure.

For mountain biking, the tyre pressure depends on all sorts of things: type of tyre, rider weight, type of terrain, weather conditions, and more. We'll take a look at all of the different aspects to consider when choosing the right pressure for your mountain bike tyres.

The pressure you choose will affect your speed, effort, grip and comfort throughout your ride! It's also important for avoiding pinch punctures and premature tyre wear.

Let's run through the options step by step!

Before inflating your mtb tyres, check the markings on the sidewall

The recommended pressure varies from one manufacturer to another. Whenever you go to pump up your tyres, it's a good habit to check the tyre's sidewall. There, you'll find a set of numbers. These tell you:

> The dimensions in inches and/or in ETRTO sizing (e.g. 29x2.3 and 55-622)
> The model and the brand
> The maximum and minimum tyre pressure (please note, the maximum pressure for your rims may be different, especially for carbon wheels)
> Which way round to mount the tyre
> The batch and serial number

This information will help you to choose the right pressure. Don't panic! We'll explain everything!

Watch out when checking the pressure listed on the sidewall as this is often the minimum and maximum for tube-type tyres (with an inner tube), rather than the "recommended" pressure. Never exceed these pressures as it could cause your tyre to burst or damage your wheels. When the recommended pressure is marked on the tyre, it's clearly specified (e.g. Rec. pressure 29 PSI / 2 BAR)


Choosing the right mtb tyre pressure: what should you consider?

When choosing the right pressure for your tyres, you need to take into account:

> The type of MTB tyre

> The minimum and maximum pressure (in bar and/or in PSI)

> The total weight: bike + rider in full kit

> The dimensions of your tyre

> The type of terrain

> The weather conditions

> The differences between the front and back wheel

1/ The type of mtb tyre

The first thing to think about is which type of mountain bike tyre you're going to inflate. There are 2 main types of mountain bike tyres:

> Tube-type mountain bike tyres, which have an inner tube, are the most common.

> Tubeless ready mountain bike tyres can be used with or without an inner tube. When they're being used in tubeless mode (without an inner tube), these tyres can be run at a relatively low pressure compared with tube-type (around 0.5 bar less). This increases grip and takes advantage of the tyre's casing.

The main advantage of tubeless is that it protects you from punctures. The puncture sealant inside the tyre means that you can keep riding even when your tyre has been pierced. Plus, without an inner tube, the risk of a pinch puncture is zero. Tubeless also eliminates rubbing between the inner tube and the tyre, so your bike will be more efficient and the tyre will be a better shape.

In-depth: what's the right pressure for tubeless tyres?

With this technology, which doesn't use an inner tube, you can pretty much say goodbye to punctures and the risk of the tyre popping off the rim.

Tubeless mountain bike tyres are a great way of getting the most out of your tyres. The pressure is lower (by about half a bar) than with tube-type tyres. As it's less inflated, the tyre's "carcass" will be able to come into contact with the floor. And it won't be stopped by the inner tube.

From fewer punctures to better comfort and performance, we tell you all about the many advantages of switching to tubeless!


2/ The maximum / minimum and recommended tyre pressure

Every tyre manufacturer sets their own minimum and maximum (and recommended) pressures for their mountain bike tyres. These values are given in PSI and in bar. You'll generally find both of these units of measurement on pumps that have a pressure gauge.

But where is this shown on your tyre's sidewall?

Example: Competition rec. pressure 29 PSI/2 bar and max. pressure 80 PSI/5.5 bar.

This means that the recommended pressure is 29 PSI / 2 bar. The maximum tyre pressure should never exceed 5.5 bar (this would be a very high pressure for a mountain bike).

Please note: the recommended pressure is not always shown on the sidewall.

3/ The total weight of the rider and bike

Your weight in full kit and the weight of your bike are important criteria when choosing the right type of mountain bike tyre and, above all, the right pressure.

The higher the total weight, the higher the tyre pressure will need to be.

Lots of manufacturers provide a table of recommended pressures based on the rider's weight, showing the lowest, average and highest recommended pressures.

Remember that these recommended pressures are for your weight in full kit (helmet, shoes, bags, etc.)

4/ The dimensions: the width of your mountain bike tyre

Generally, the tyre dimensions are given in standard units, i.e. in inches.
Example: 29x2.2. The first part (29") refers to the wheel's diameter. The second part (2.2") refers to the tyre's width (or cross-section).

There are various different widths: 2.1, 2.2, 2.3,... and even 2.8!

The wider your tyre, the more contact it has with the ground. To guarantee good grip and control, the wider your tyre is, the lower the pressure can be.

To compare different manufacturers' tyre dimensions, you can also look at the ETRTO standard (European Tyre and Rim Technical Organisation). These values are given in millimetres:

Example: 50-559. 50 mm refers to the tyre width. 559 refers to the inner diameter of the tyre.


5/ The type of terrain

Is today's mountain bike route quite fast? Rocky? With a lot of elevation gain? The type of terrain is something to consider when working out the best tyre pressure. 

As you can probably imagine, a bike tyre will behave differently on rough ground to how it would behave on a muddy field, and therefore needs a different pressure.

The rockier or damper the terrain, the lower your tyre pressure will need to be to stick to the ground. The faster the terrain, the higher the pressure should be to pick up speed.

6/ Front wheel and rear wheel: the pressure varies

One last thing to think about is the pressure difference between the front and back wheel. Just follow the golden rule: the back wheel should run at a higher pressure than the front wheel.

Why?Because your weight goes through the back wheel more than the front. And that's not all! The front wheel is what gets you past obstacles, so you want a slightly lower pressure to stay glued to the ground. As for the back wheel, it's all about driving your bike forwards, so it should be pumped up a bit more to improve your performance / efficiency.

Don't overdo it: we recommend starting with just 0.1 or 0.2 bar extra at the back. You can then refine it based on how it feels!


What's the risk if you over- or under-inflate your tyres?

With under-inflated tyres, the main risk is a loss of performance. You'll feel sluggish, particularly on faster terrain. If this happens, don't hesitate to top up trailside with a few extra bars. As well as that, there's a greater risk of getting a puncture with under-inflated tube-type tyres. It also wears out the tread faster.

With over-inflated tyres, it reduces the contact area with the ground. You'll notice this in particular when clearing obstacles on rough or rocky terrain. And with a higher pressure, the cushioning isn't as good. This will make your entire ride less pleasant. On certain "softer" terrain (mud, sand, etc.) it can even increase your risk of taking a tumble.

Properly inflating your mtb tyres

The best way to find the perfect tyre pressure is with a bit of trial and error!

Find a short loop (5-10 minutes) that goes over as many types of terrain as possible (mud, rough ground, roots, cobblestones, etc.). Inflate your tyres to the highest recommended pressure, then do a lap. If the tyre is too stiff and you're not comfy enough, or feel you're losing grip on corners, lower the pressure. Repeat until you find the right tyre pressure.

Always remember to take a bike pump with you. It's totally worth it!

In short, as a mountain biker, you should pay close attention to your pressure at all times!

The lower your pressure, the harder your tyres will work for you and the more comfortable you'll be. The higher your pressure, the more efficient you'll be and the faster you'll go. The bigger your tyre, the lower you'll be able to take the pressure.

You now know absolutely everything about choosing not only your tyre, but also the perfect tyre pressure to keep you comfy and safe. So what are you waiting for? Grab your bike and make the most of the great outdoors.

A well-inflated tyre is essential for your sport. So remember to frequently check your tyre pressure.