How To: Find the right tire pressure

Create maximum ground contact and traction, while limiting tire deflection

How To Tech Tires
with 2.3″ width tires, riding intermediate terrain, start at 35 psi and adjust accordingly. Photo courtesy of Art's Cyclery

With 2.3″ width tires, riding intermediate terrain, start at 35 psi and adjust accordingly. Photo courtesy of Art’s Cyclery

Editor’s Note: This article is courtesy of the team at Art’s Cyclery. The original post can be found here.

To the uninitiated, mountain biking is a sport full of mystical knowledge, soaked up from the earth via the two-wheeled talisman underneath you. More time spent riding results in more knowledge gained through this intimate connection between rider, machine, and universe.

Unfortunately, the only thing proven to result from extensive contemplation while perched on a bicycle is an ever-growing desire to leave more and more of the “real world” behind as you pedal off toward a new horizon. Real, proven, practical knowledge that results in more enjoyment on the bike is luckily much easier to find, and the ins and outs of tire pressure are an important example.

There’s nothing mysterious about the goal of correct inflation: create maximum ground contact while limiting tire deflection. Too much pressure will prevent the tire from conforming to and absorbing irregularities in the terrain, while too little pressure causes sidewalls to collapse, resulting in tire squirm, a rough ride, loss of control, damaged rims, and possibly the tire coming off the rim. Optimal tire pressure is high enough to maintain shape and traction through turns, but also low enough to conform to obstacles without causing deflection or bottoming out on the rim.

Mountain bike tire pressure is dependent on these variables:

  • Rider weight: More weight = more tire pressure.
  • Tire volume: More volume, either in width, diameter, or a combination, requires less pressure. “Plus” and “fat” tires represent the extreme of this example, with plus tires requiring less than 15 psi and fat tires able to perform with as little as 4 psi in soft conditions.
  • Terrain: Rougher terrain requires less tire pressure… to a point. You need enough bottom-out resistance without creating a harsh, uncontrollable ride. Optimal pressure is where the tire compresses enough to almost touch the rim on the trail’s biggest impacts.
  • Rider Skill Level: Faster, more aggressive riders need more tire pressure, since they will be cornering and hitting obstacles with more force, requiring more bottom-out resistance.
  • Tire Construction: Lighter, thinner tires require more pressure than thicker, reinforced tires.
  • Tubed or Tubeless: Running tires without tubes greatly reduces the chance of pinch flats, allowing for lower pressures in tubeless compared to tubed tires.
If you find yourself wallowing in corners, or bottoming your tires out harshly, add 3 psi. Photo courtesy of Art's Cyclery

If you find yourself wallowing in corners, or bottoming your tires out harshly, add 3 psi. Photo courtesy of Art’s Cyclery

Where to start? Here’s a quick guideline to dialing in your mountain bike’s tire pressure. These are not the Commandments of Pressure; if you find that following these numbers leaves your bike feeling too bouncy or too sluggish, then adjust accordingly. The intention is to get you thinking about which direction to run your pressure according to your riding conditions.

For most riders weighing from 160 to 180 pounds, with 2.3″ width tires, riding intermediate terrain, start at 35 psi.

  • Drop 5 psi if tubeless
  • Run 2-3 psi less in the front tire than in the rear tire
  • Add or subtract 1 psi for every 10 pounds you are over or under the stated weight range, without dropping below 25 psi to start
  • Add or subtract 2 psi for every tenth of an inch your tires are under or over the stated width
  • Write down your starting psi and pay attention to cornering and bottoming out on your next rides
  • If you find yourself wallowing in corners, or bottoming your tires out harshly, add 3 psi
  • If your bike feels skittish, bouncy, or harsh in rough stuff, subtract 3 psi
  • Every time you change your psi, write it down!

Unfortunately—or luckily, depending on how you look at it — finding your perfect tire pressure will take some trail time. However, once you understand how your bike reacts with varying tire pressure over specific terrain, you will be able to eliminate one more variable in your performance equation.

What are your secrets for nailing tire pressure? Let us know in the comments section below.

About the author: Arts Cyclery

This article was originally published on the Art's Cyclery Blog. Art's Cyclery is dedicated to offering free expert advice, how-to videos, and in-depth product reviews on to help riders make an educated decision when selecting cycling gear.

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  • ean says:

    I find that tire roll is the limiting factor for me. I am 190 with gear. When I am riding old school trails I can get away with like 29 psi. When I am on newer flow trails with lots of banked corners that you can really lean into I need like 32 or 33 psi to not feel the tire roll. I am running Ardents with EXO sidewalls set up tubeless.

  • butch says:

    how much PSI do you lose to the pump? Just unhooking the pump seems to ruin any fine tuning of PSI.

    • alias says:

      As long as you are using the same pump it does not really matter how much you lose. It can be off 5 psi, but as long as its ALWAYS 5 psi who cares, you will still find your sweetspot. Consistency is more important than accuracy in this situation.

    • DrDave says:

      No, if done quickly, nearly all of the hiss you hear will just be the pressurized air in the hose. If the gage pressure falls off fast, you can be sure that this is the case.
      I ride road bikes also, and I have often gone back to verify the pressure that I just pumped to, using a gage. So with much-fatter offroad tires, there doesn’t need to be even 1psi loss when removing the chuck from the valve.
      As for my off road tire pressure, I run generously-sized 650bX2.3″ WTB tires (with tubes) on huge 53mm-wide rims. I weigh 138lbs and use only 18psi, any less and the tires slide and wash out. No pinch flats in six months of riding in rocky terrain at modest speeds.

  • jlandry says:

    Unlike a shock the percentage of the air volume it takes to fill the hose when filling up you tire shouldn’t have a huge effect on the pressure you read. If you really wanted to get technical with it checking with a standalone pressure gauge would be the way to go.

  • Kamalapati Khalsa says:

    I’m currently running American Classic Wide Lightning wheels (27.5) with Specialized 2.1 Ground Control tires (tubeless). I weigh about 175lbs. I run them between 17 and 20 psi depending on what I’m riding and things have been great. I use a compressor with a very accurate gauge.

  • duder says:

    These pressures seem way too high going by the guidelines…

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