EMTB tyre pressure guide: all the essential info

AMFLOW

28/02/2025

Tyre pressure is one of those things that you don’t notice until something goes wrong. When your eMTB tyre pressure is set up right, your bike rides smoothly, handles confidently and pedals efficiently. But when the tyres are either over-inflated or under-inflated, things start to feel ‘off’. Fortunately, tyre pressure for mountain bikes is quite an easy thing to fix, requiring just a track pump and some know-how.

In the following guide we’ll take you through everything you need to know about tyre pressure for your electric mountain bike.

In This Article

What is tyre pressure and why does it matter on your eMTB?

Tyre pressure is the amount of air in your tyre, relative to the full volume of the tyre. When pressure is high, your tyre feels hard. When it’s low, your tyre will feel squidgy. Neither of these is necessarily wrong, because a big part of finding the right eMTB tyre pressure comes down to context and preference.

Tyre pressure for mountain bikes is measured in one of two units: psi and bar. Bar is more common in Europe and the rest of the world, while psi is predominantly used in the USA.

The pressure that you run your eMTB tyres at is quite an impactful feature of your bike. It can affect the handling, as well as how exposed you are to punctures or wheel damage. Over the course of a day on the trails, having your tyres set a few psi too high or too low could make a big difference to how much you enjoy yourself.

In general, higher pressures make for a more efficient and fast bike when you are pedalling, while lower pressures make you better equipped to handle bumps, lumps and technical challenges, and you are generally more comfortable.

What can influence mountain bike tyre pressure?

There are a few main factors that influence eMTB tyre pressure.

Tubeless or inner tubes

Tubeless tyres don’t need to be run at pressures as high as their inner tube equivalent. This is because inner tubes are susceptible to ‘pinch flats’, where the tube gets pinched between the rim and some external object (like a stone or pothole) through the tyre. This is a very common cause of flat tyres in mountain biking, and is a chief factor in why most MTB riders choose to run tubeless. The Amflow PL comes with tubeless-ready tyres (which means they come with inner tubes but can be set up to run tubeless).

Intended activity

Different styles of mountain biking require different levels of tyre pressure. Hardtail MTBs and bikes designed for cross-country normally run at higher pressures than enduro or downhill machines. This is because downhill and enduro bikes go fast downhill, fly off jumps and down drops, and need to be able to absorb those hits. Sure, the suspension does a lot of that work, but the tyre pressure also has a part to play. By comparison, cross-country bikes need to be more efficient when pedalling, and so a higher pressure is recommended.

Weight

Weight of the rider, plus anything being carried on the bike, are crucial in setting tyre pressure. Two riders, one weighing 45 kilograms and one 90 kilograms would need to set their tyre pressures very differently, even if they were both using the same bike model and tyre. If you decide to take your eMTB on a bikepacking adventure, the extra weight should be accounted for with a small increase in your tyre pressure. Additionally, it’s worth remembering that an e-bike’s motor system typically adds about 10kg to the system and this may not be accounted for in a tyre manufacturer’s marketing materials.

Climatic conditions

The pressure in your tyre actually changes based on the atmospheric conditions. When it’s cold out the pressure decreases, and when it’s warm the opposite happens. Your wheels and tyres also warm up while they’re being used, which again can alter the reading you get from a pressure gauge. A good rule of thumb is that if it’s very, very hot out, release a little bit of the air from your tyre before you set off from home.

How to find the perfect tyre pressure for your eMTB.

Your first port of call should be the sidewall of the tyre. Almost all tyre brands put the recommended upper and lower pressure limits on their product. It’s important to remember these numbers represent the extremes, so it’s unlikely you’ll actually enjoy riding a mountain bike with the tyres pumped to the maximum number on the sidewall.

Once you have a rough idea of the limits, factor in your weight and the type of riding you want to do. If you are a heavier rider, move closer to the maximum. If you are going to be riding down a lot of technical descents and taking your bike off jumps, reduce the pressure a little.

For the Amflow PL platform, we chose to spec the bike with what we think are among the best eMTB tyres – a Maxxis Assegai MaxxTerra front tyre and Maxxis Dissector MaxxTerra rear tyre. For these, we’d recommend 25psi or 1.7bar as a good ‘starting point’.

Ultimately, there’s only one way to really figure out the pressure that’s best suited to you and that is by getting out and riding your eMTB. If you can do some test runs in a nearby trail, with easy access to your pump and pressure gauge, that will help you with finding what works. If you are getting a lot of rim strikes and the wheel feels sludgy in turns, you should add some air. If you feel like you are being bounced around on top of the bike and the wheels are slipping when you pedal hard, you probably need to let some air out.

Setting the right tyre pressure for your eMTB is essential for optimising performance, comfort, and handling on the trails. Factors such as your weight, riding style, tyre type, and even weather conditions play a crucial role in determining the ideal pressure. While tyre manufacturer recommendations provide a useful starting point, fine-tuning your pressure through real-world testing is the best way to find what works for you. Remember, whether you prefer higher pressures for efficiency or lower pressures for better grip and shock absorption, the key is to adapt your setup to suit your unique needs and the terrain ahead.

Amflow PL

The Amflow PL electric mountain bike offers 850 watts of power in an ultra-light sub-20kg build. With an unrivaled combination of power, range, and weight, it delivers the ultimate ride.

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