Know-How, Workshop - July 24, 2016

What tire pressure should I run in my MTB?

When riding the only contact point (hopefully) between us and the ground is our tires – influencing how our bike feels more than any other expensive ‘must have’ accessory we could hope to buy! But how many of us know how to find our perfect tire pressure? It’s time to find out how!

What pressures do you run in your tires? When did you last check? When asked that question on the trail most of us reach down and give the tire a gentle squeeze, “hmmm, I run about that much”. If you want to get the best out of your bike, the first and cheapest place to start is the tire pressures, get those right and you are off to a great start. Here are two methods, one fast and dirty to get you near enough and the other to get your setup dialed.

So what’s the magic bullet pressure, one that will make you shred harder than Fabien Barel? We have all used the recommended pressures in our car tires right, so there must be one for our bikes? Well, here’s the bad news, there isn’t one! Even top racers run different pressures, heavier riders like Greg Callaghan, Jared Graves and Jamie Nicholl all run 1.85 Bar (27 Psi) front and 2.0 Bar (30 Psi) rear – but lighter riders like Joe Barnes and Jerome Clementz run lower pressures, 1.6 Bar (23 Psi) front and 1.95 Bar (29Psi) rear and 1.5 Bar (22 Psi) front 1.7 Bar (25 Psi) rear respectively – showing the diversity in style and pressures.

Tire pressure is as personal as the fit of our saddles or what beer we choose at the bar, and depends on weight, riding style, tire choice and the trails we ride!

There’s no magic number, but if you’re running very low or high pressures ( 3 Bar) you are probably not getting the best from your bike.

If you’re simply after a setting that will work well in most cases then our experienced testers recommend a base setting of:

1.8 Bar (26 Psi) front and back in a standard 2.35 -2.4 inch tubeless tire
2.0 Bar (29 Psi) front and back in a standard 2.35 -2.4 inch tubed tire

If you are running bigger 2.8 – 3.0 inch Plus tires our Plus testers highly recommend:

1.2 Bar (18 Psi) front and back in a standard 2.8 – 3.0 inch tubeless tire
1.4 Bar (20 Psi) front and back in a standard 2.8 – 3.0 inch tubed tire

These pressures will work well in most cases, but if you want to maximise your riding enjoyment and unlock extra grip there is a better way to find your optimum setup that works for you.

Tire pressure is all about balance, too much and you will lose traction, too little and you increase you chance of a pinch puncture!

The perfect balance

When it comes to finding the perfect pressure, it’s all about finding that balance between grip and stability.

Too high: Higher tire pressures help support the sidewall of the tire offering increased stability and increased protection for the rim, but go too far and traction will be drastically reduced as the contact patch shrinks and the ride will feel harsh.

Too low: Low pressures increase grip from the larger contact patch and improve cornering traction as the softer tire can wrap around trail imperfections. However run the tires too low and you drastically increase the risk of rim damage from square edged hits, and the softer air pressure reduces the natural spring of the tire which can create a wallowy and unstable ride at speed. In hard turns the tire tends to lack stability in the sidewall and can feel vague.

To find our optimum tire pressure it’s important to find a balance that provides enough protection for the rim while giving good cornering traction and stability.

Always try and use the same pressure gauge .as you will find lots of variation between different devices.

All gauges are not created equally

Let’s just get one thing clear, not all tire pressure gauges are created equal and you are likely to see some variation with different gauges. The best thing to do is always use the same gauge for your own tires. Invest in a good gauge and look after it. Most pro riders have their own gauge that they guard fiercely.

How to find your perfect tire pressure

It’s time to hit the trails! Arm yourself with a pump and gauge and find a short one – two minute test loop with some nice flat corners, berms, compressions and roots, representative of the terrain you ride but not too gnarly, you want to be able to concentrate on feel while you ride, not trying to stay out of the bushes! To begin start with a higher pressure in your tires, so you can feel what a very high pressure feels like, if you run tubeless and are not really heavy try 2.2 Bar (35 Psi) front and back, if you are heavier than 80 kg or run tubes try 2.4 Bar (40 Psi).

Ride the trail (take it easy as the bike will feel different) and concentrate on:

How much grip you have in turns?
How does the bike feel over roots and hits?
How harsh is the ride?
Is the rim being hit?

Did you get all that? OK now head back to the start and drop the tire pressure 0.2 Bar (3 Psi) front and back and repeat the trail, once again observing how the tires feel and how much grip you are finding. Repeat, again and again, dropping the pressure each time, try and get a feel for what’s going on.

“If you start to feel bumps impacting the rim, you have gone too far so don’t go any lower.”

As the tire pressures drop you will start to encounter increased grip and traction, but as the pressure becomes too low, you will feel the tires start to feel vague and wallowy in turns and unstable at high speeds. If you start to feel bumps impacting the rim, you have gone too far so don’t go any lower.

Try to find that point where any further pressure drops no longer result in an increase in performance. You want to feel good grip but also stability from the tires. This is getting near to your optimum setting. Now try experimenting with the balance between front and rear, you can normally run a little less pressure in the front as the bottom bracket distributes around 40% to the front and 60% weight to the rear. Try 0.2 Bar (3 Psi) less in the front and see how that affects grip, play around a little and get a feel for how it changes the ride.

You now have a good base setting to work from, write it down somewhere – this is your BASE setting and is your magic number.

Once you have a good base setting you are ready to shred and will have the experience to change pressures to suit the trail.

You have a BASE setting? Whats next.

Now you have your BASE setting and know how pressure impacts the ride – you can now optimize your pressures with ease. Are you carrying more weight (heavy pack) or looking for more traction on muddy trails, add or remove pressure as needed! Don’t forget to always use the same gauge.

What pressures should I run in MTB Plus Tires?

One advantage of Plus tires is that you can run slightly lower pressures to benefit from the massive contact patch grip. Optimising Plus tires are no different from conventional tires, but you can start a little lower at the beginning as Plus sized tires tend to suit lower pressures. Try 1.6 Bar (25 Psi) front and rear at the beginning of the process.

Conclusion

Whether you want to perfect your setup or just use our recommended pressures, you will quickly learn that tire pressure is the easiest and cheapest tune-up for your bike. Once you understand how different tire pressures influence performance you’re well on your way to enjoying more grip, control and fun from your bike.

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