(Last updated on January 17th, 2023)
I bounced off every root and rock and slipped on every patch of mud. The final moment of frustration happened when I just about slipped off the trail and down the embankment into the river. I was done. I got off the bike and walked the final tenth of a mile of trail, disappointed in myself.
- Why A Mountain Bike's Tire Pressure is Both Important and Mysterious:
- Special Considerations for Your MTB Tire Pressure
- How to Figure Out Tire Pressure
- Real-World Examples of Tire Pressure
- How to Find Your Ideal Tire Pressure
- Frequently Asked Questions
I thought my new chunky tires were the answer to mastering this trail, so what could have gone wrong? It was my tire pressure. I learned the hard way that every rider, trail, and set of tires has a ‘sweet spot’ for tire pressure. But unfortunately, my pressure was just way too high for the terrain. Since then, I’ve done a lot of work to master the art of tire pressure.
In this article, we’ll clear up some of the confusion around mountain bike tire pressure. First, we’ll tell you why it’s important and why it’s challenging to figure out. Then, we’ll give over some of the variables surrounding tire pressure and give you some guidelines. Let’s get started.
Why A Mountain Bike’s Tire Pressure is Both Important and Mysterious:
Tire pressure has evolved over the years just as our bikes have. For example, in the 80s and 90s, road bikes had super skinny tires pumped up to 110 PSI – now, the pros are running tires as wide as 28s with much lower pressure. Yet, the roads are the same -so what changed?
We realized that there is a sweet spot to tire pressure. Too high, and it bounces off every little crevice in the pavement. Too low, and you risk pinch flats. The same is true for mountain bike tires but at an exaggerated level.
If your mountain bike tire pressure is too high, like mine was, you’ll bounce off every tree root, rock, or bump in the road. As a result, you’ll fatigue quickly because your body will absorb every lump, bump, and vibration, too. And it will slow you down and make you more tired because you’ll use more energy to compensate for bouncing off the terrain.
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On the other hand, if your tire pressure is too low, you’re at risk for pinch flats. The rim of your bike will ‘pinch’ the tire and tube when you roll over something hard. It can slice your tire and even damage your tire rim, ruining your ride.
There are several considerations you need to take when you are thinking about your tire pressure.
When figuring out tire pressure, one of the first considerations is your weight. If you’re a lighter rider, you can go with less tire pressure because you don’t put as much force on the tire. On the other hand, if you’re heavier, you’ll need a little more tire pressure. If, for example, you’re going bike packing and loading down your bike with tons of gear, you’ll want even more.
The tires you use will also affect your tire pressure. If you have extra wide, chunky boi tires (also known as wide, knobby tires), you can run a lower pressure than if you have smaller tires. So, for example, if you got 2.5-inch tires on your bike, you can run a bit lower pressure than if you’re sticking with 1.9 inch.
Tubed tires are more likely to get pinch flats, especially on a mountain bike. So you’ll need a higher pressure to protect the tube than if you’re running tubeless, which can go a little bit lower.
Larger rims might be a little bit heavier, meaning you can run lower tire pressure. Conversely, thinner rims, which are lighter, need a little bit higher pressure.
How good are you at mountain biking? If you pick great lines and can avoid puncture-causing obstacles, you can run a lower pressure. On the other hand, if you just send it and hope for the best, you might need a little bit higher pressure to protect your tire from punctures.
There’s always a balance between speed and rolling resistance. Lower pressures may make you roll a little bit slower, while higher pressures may help you roll a little bit faster, as a general rule. However, there is a point of diminishing return in either direction – too high, and you lose speed because you bounce off of everything. Too low, and the tire deforms so much that you get much more rolling resistance, which slows you down.
How do you want your ride to feel? Do you want it to be a little cushier? Do you want a little extra grip? Go for lower pressure. Do you want it to feel fast, hard, and even slippier? Then, go for higher pressure.
The terrain is a pretty big piece of the tire pressure puzzle. Practically speaking, the harder and firmer the terrain, the higher the tire pressure should be. Conversely, the sloppier, rougher the terrain, the lower your pressure should be, but it still needs to be high enough to keep your tire from bottoming out on the rim.
On the other hand, if you’re hitting lots of rocks, you might want higher pressure because too low can cause a puncture. Lots of mud calls for lower pressure to increase grip, while a hard, dry trail can mean you need higher pressures.
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There’s a sweet spot when it comes to mountain bike tire pressure and speed. If you took your mountain bike on a road ride, you would find that your speed feels a lot slower than your friends on a road bike. On the other hand, if you tried to take your road bike on the trails, you’d have to go extra slow (and walk a lot) because the thin tires and high pressure don’t grip as well.
So when it comes to mountain bike tire pressure, if your pressure is too high, you’ll actually end up going slower and wasting energy because the tire won’t grip properly, you’ll bounce off of obstacles, and slide around. If your pressure is too low, the tire will have too much friction and will catch on obstacles, slowing you down and putting your rim and tire at risk of damage and puncture.
But when you find that sweet spot in the middle, you’ll have just the right amount of grip on the surface of the trail to give you both speed and traction.
So What Should Be Your Mountain Bike’s Tire Pressure?
You can use this mountain bike tire pressure chart as a handy guide to get you started on the road.
Stans NoTubes offers a simple formula to determine your recommended tire pressure for tubeless tires. This gives you an easy starting PSI for XC riders.
Take the rider’s weight in pounds and divide by 7. Add 2 PSI for the rear tire pressure and subtract 2 PSI to get the front tire pressure
For example, imagine your rider weighs 140 pounds.
140 divided by 7 = 20. So you’re front tire pressure would be 18, and the rear pressure would be 22, although this might be too low for the recommended pressure on the sidewall of your tire.
GMBN Tech demonstrates a range of tires, tire pressure, and situations in their video.
On the other hand, Canyon.com recommends that new riders start with 27 PSI in the front with 30 PSI in the rear when running tubeless. But if you have tubes, try 32 PSI in the front and 35 PSI in the rear to protect against flats.
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If you look at the tire’s sidewall, you’ll see a range of tire pressures. The manufacturer recommends you always stay within these pressures for safety and performance. And while people do go outside of these recommendations, you do so at your own risk to yourself and your equipment. Failing to follow the recommendation can cause injury and violate any warranty on the tire itself.
That being said, you can find your ideal pressure by starting in the middle of that range. Then, it’s time to experiment!
You can go up or down a little bit based on the following:
|Increase Tire Pressure If:
|Decrease Tire Pressure If:
|You have smaller tires
|You have bigger tires
|You have smaller rims
|You have wider rims
|You have tubes
|Your tires are tubeless
|It is dry and hard packed
|It’s wet and muddy
|You’re a heavyweight
|You’re a lightweight
|You’re cornering aggressively
|You’re riding on loose rocks
|You’ve got a hardtail
|You have full suspension
|You got mad skills
|You are a slow and cautious rider
Do some test rides and take notes on the tire, rim size, terrain, etc. Once you find a pressure you like (or that you can’t stand), use a digital tire pressure gauge to measure it.
Final Thoughts on Best Mountain Bike Tire Pressure
There are no hard and fast rules to finding just the right tire pressure. It all just depends on the rider, the terrain, and the tires. Now that you understand the basics, you have a great starting place. Then go out there and experiment until you find the tire pressure that makes you feel confident and in control of your ride.
Frequently Asked Questions
Generally speaking, you should try to stay within the minimum/ maximum tire pressure listed on your tire’s sidewall. If you use a different pressure than what is stated, you do so at your own risk to yourself and your equipment.
You’ll bounce off every rock and root if your tire pressure is too high. As a result, your ride will feel slippery and out of control, and you’ll fatigue quickly.
If your tire pressure is too low, you’re at risk of puncture, pinch flats, and rim strikes which could damage your wheels. In addition, you’ll feel sluggish, like the bike is heavy, and you’ll run out of energy quicker than expected.
A good pump will have a pressure gauge built in. However, if you use different pumps, you might get slightly different readings on each pump. For best results, use the same digital pressure gauge every time.
Here are a few tips to know if you need to adjust your tire pressure or if it is just right.
|It feels harsh and skittish
|Tire feels stable
|The ride feels sluggish and soft
|Traction feels less when braking, cornering and accelerating
|You have just the right amount of traction
|You feel rim strikes or knocks when you hit a root or rock
|Bouncing off roots and rocks
|You don’t have rim strikes
|Decrease in acceleration
|Slides off roots uncontrollably
|The ride feels under control, and the bike responds predictably
|Tire folds when cornering
|You can’t hold the line when you ride off-camber
Amanda Whittington is an expert writer, impassioned cyclist, and musician. Coming from a diverse educational background, Amanda discovered a deep-rooted passion for encouraging others through her love of all things cycling, writing, and inspiring hope.
You’ll likely find Amanda pouring over bike specs, comparing the hottest cycling tech, and sporting the latest jerseys while juggling the demands of her editorial calendar, training schedule, tiny homestead, and 6 busy kids.
She spends her free time absorbed in her own gardening and fitness, cycling, and reading, all while encouraging adoption and foster care, championing the underdog, and of course, working with her chickens and goats.