Pro cyclist Alison Tetrick has a mantra: Lower tire pressure, lower life pressure. It’s a joke. Sort of. But not really. When she was racing the World Tour in the late aughts, 23mm tires pumped to a wagon-wheel rigid 120 psi were standard fare. And it was terrifying.
Rock-hard tires may sail over glass-smooth fresh asphalt, but put them on most well-worn roads and they bounce like Super Balls over every imperfection and chatter through corners rather than conform to the road, ramping up your mental and physical fatigue.
In 2017, Tetrick switched to gravel racing, later saying, “I needed to lower the pressure in my life, and the tire pressure in my wheels.” She was talking about switching to a racing discipline that was a bit more fun-forward than the pure road scene at the time. But she also found that lower tire pressure literally lowered her stress levels on the bike…once she got used to it.
“In my mind, higher tire pressure meant fast. So, my mechanic would want to put 35 psi in my tires for gravel, and I couldn’t fathom it. I’d be like, ‘How about 40?’”
“Lower tire pressure is more comfortable and it’s more confidence-inducing for me, especially on rough descents,” Tetrick says, noting that she now also runs wider tires and lower pressure on the road bike. “I run 30 to 32mm tires with 60 psi. I don’t pump up my tires until they get below 50,” says Tetrick, who used to consider 90 psi low. “More tire patch on the road is also faster on bumpy roads.”
So, should we all unscrew our collective Presta valves, tap our air pressure down to 60, and ride happily ever after? Nope. While it’s true that running the right tire pressure may just be the single best performance improvement you can make on your bike, the proper psi depends on a host of factors, including tire and rim widths, terrain, ambient temperature, weather, and rider weight.
This complex matrix of factors is why the internet is filled with tire pressure charts, guides, and calculators, and why you’ll see riders obsessively squeezing their tires, their friends’ tires, and their competitors’ tires if they can get away with it before a big event. There’s no one magic number for everyone on every ride.
You have to experiment to find the pressure that feels just right for you. But this guide will give you the starting points, insights, and expert advice to nail your tire pressure for every ride.
—Selene Yeager
The Ultimate Guide to Tire Pressure Starts Here
- Make Your Ride Faster, Smoother, and More Efficient
- How Does Weather Affect Tire Pressure?
- How Tire Construction Influences Tire Pressure
- Bike Pump Buyer's Guide
- Our Gear Editor’s Top Tools
- Tips for Getting the Most Accurate PSI Reading
Make Your Ride Faster, Smoother, and More Efficient
A great tire optimizes rolling resistance, grip, and durability. While tread compound—the secret sauce of tire brands—plays a role in this optimization, says Oliver Kiesel, tire product manager for Specialized, the biggest influence is tire pressure. Here’s why.
More Air Isn’t Always Faster
Road racers used to run narrow tires at rock-hard pressures because rolling resistance drops as pressure increases, which reduces casing flex (how the tire deflects under load) and makes the ride more efficient. But that’s only part of the equation.
What’s true on a perfectly smooth surface—like the metal drum used in lab testing—isn’t in the real world, says Josh Poertner, owner of Silca, a maker of high-quality pumps. On the road, past a certain pressure, rolling resistance increases, and quickly, as even fresh pavement or concrete has thousands of tiny little bumps. The tire deforms around those imperfections, thanks to casing flex; but as pressure increases, the tire deforms less and starts to bounce over them. That bouncing, which Poertner calls impedance, is inefficient. Above a certain pressure, it overcomes the benefit of reduced casing flex and makes the tire slower.
Poertner credits independent engineer Tom Anhalt with making this discovery around 2007. While Poertner was an engineer at Zipp, he was able to repeat the finding in real-world testing, including in different tire sizes at different pressures. That is, while the exact spot that friction begins to increase—which Anhalt and Poertner call “break-point pressure”—varies by tire model, size, and riding surface, it’s almost universally true that every tire has a sweet spot for the most efficient ride.
So what’s the sweet spot? It varies based on the tire construction, its width and volume, and of course factors like rider weight and terrain. You’re always trading off attributes—like speed versus traction—against each other. And in different disciplines, like mountain biking or gravel, grip is more important than optimal rolling resistance. But there are guidelines to dial in your magic number:
- The rougher the surface, the lower the sweet-spot pressure. Because of that, for narrow tires there may not be a sweet-spot pressure that’s practical on rough surfaces; you simply need wider tires.
- Ideal pressure for efficient rolling resistance is higher than the optimal pressure for comfort.
- The pressure for best traction will be lower than for optimal rolling resistance.
- For flat protection, set your pressure for the roughest surface you’ll encounter for more than a short section. If you find yourself pinch-flatting consistently even at higher pressures, you need a wider tire.
Online calculators from Silca and SRAM, which take into account variables as detailed as inner rim width, tire casing type, and riding surface, are your best starting point. Experiment with slightly higher and lower pressures to find what works best for you.
Comfort Boosts Endurance
Impedance doesn’t only affect rolling resistance; your body feels it as vibration, whether it’s high-frequency road buzz or the higher-amplitude, lower-frequency jolts of washboards. According to Poertner, anything the bike doesn’t soak up—through tires, suspension, or padding—your body must. Vibration causes the body to tense up and absorb the sensation, says biomechanist Todd Carver, head of human performance at Specialized.
A Specialized-funded study published last year in the journal Medicine & Science in Sports & Exercise simulated the effect of vibration from Paris-Roubaix-style cobbles and found that a rider’s response is a “whole-body phenomenon,” using stabilizing muscles to brace and counteract the sensation. In a short, sub-30-minute ride at various power outputs, the cobble-style shaking was associated with increases in oxygen consumption (2.7 percent) and heart rate (5 to 7 percent). You probably also associate vibration with sensations like numb or tingling hands and hot spots on your feet. Finely-tuned tire pressure is effectively a free way to counter those effects.
Front and Rear Balance Is a Myth
There’s a persistent belief that you should adjust tire pressure for your front-rear weight balance, which is always higher in back. Don’t. Weight distribution on a bike isn’t static. For example: under hard braking like on a descent, most of your weight is shifted onto the front wheel, exactly the moment you don’t want an underinflated tire squirming around underneath you. It’s fine to reduce front tire pressure 2 to 3 percent from rear for comfort, but not more.
—Joe Lindsey
Tire Pressure with the Pros
➤ Tips and Tricks!
Everyone is different. Everyone’s weight is different. Everyone’s riding style is different. On trails, if your bike feels skittish, and you’re feeling like it’s sliding out a lot, then bring your pressure down a little bit. If you’re hitting the rim over rocks, or you hear your tires making the shooping sound, you can add a bit more. It takes time, but you’ll create some guardrails of the highest and lowest pressures you can run, and you can play within that range, depending on the course. | Eliot Jackson, former pro downhiller and founder of the Grow Cycling Foundation
How Does Weather Affect Tire Pressure?
In the Wet
Optimize wet-weather traction by dropping your pressure without going so low you’re vulnerable to pinch flats, says Specialized product manager Oliver Kiesel. Their pro team partners typically reduce tire pressure 5 to 7 psi for wet racing. But that’s just a starting point, and mostly applicable to conventional, 26mm to 28mm road tires. For wider tires on pavement, try dropping 3 percent from normal pressure and adjust as needed.
Hot and Cold
Air pressure changes about 2 percent for every 10-degree (Fahrenheit) shift up or down. If you inflate your tires to 80 psi in a 70-degree garage and then ride in 30-degree temps, the tires will be about 75 psi outside. You can adjust tire pressure to compensate, but you don’t need to worry, say Kiesel and Silca’s Josh Poertner.
Even on a hot day, when temperatures directly above black asphalt can top 130 degrees Fahrenheit, any given patch of tire that briefly comes in contact with the road cools as it spins. The pressure change inside the tire is too small to perceptibly affect grip, comfort, or rolling resistance. Contrary to myth, tube blowouts caused by sustained rim braking aren’t pressure-related. Instead, the rims heat up, prompting the rubber tubes to soften and fail. On steep descents, brake hard only when needed and then let off, or alternate front and rear braking. A few seconds of free rotation can drop the temperature at the brake surface by 100 degrees.
Cold weather presents different challenges. Adventure cyclist and wheel-builder Mike Curiak regularly fat-bikes in subzero conditions and says that below 15 degrees Fahrenheit, tires start to feel different: “They get really stiff, slow, and inefficient.” He says the sensation is more pronounced in tires with a lower threads-per-inch (tpi) count, while tires with higher tpi casings that are more flexible in normal temperatures are less affected.
He’s also noticed pressure fluctuations due to extreme cold, especially if a bike is stored in a heated space. If you ride in winter on a fat bike or even a mountain bike with plus-size tires, it’s worth investing in a gauge that has precise resolution at low pressure. Where 1 to 2 psi isn’t a huge change on a gravel tire, it can be 10 to 20 percent on a high-volume fat-bike tire.
—J.L.
Tire Pressure with the Pros
➤ What is the Most Surprising thing you’ve used as a patch?
Rubbing dirt or moss in with a tire plug to help it seal. | Jenn Jackson, Canyon MTB Racing, 2021 Canadian National MTB Champion
How Tire Construction Influences Tire Pressure
How does the width of a tire affect how much air you need to put in it?
The greater the width, the higher the tire volume. And while there will be more air in a gravel tire than a road tire, for example, the larger tire requires less air pressure since there’s more surface area to distribute the pressure, reducing the chance of a pinch flat. Plus, riding style dictates tire size and corresponding pressure. For instance, 45 psi on a road tire will give you a pinch flat before you’re out of the driveway, while 45 psi on a mountain bike tire will bounce you off the trail. That same psi on a gravel grinder? Okay, we’re getting closer.
Low-volume tires like 26mm to 30mm road tires take a much higher psi (80 to 130), while standard mountain bike tires will need a much lower psi, around 25 to 30 for most bikes. Midrange tires on hybrids or gravel bikes usually run between 45 and 70.
Is pressure the same for tubeless, tubular, and clincher tires?
Tire pressure can be adjusted based on materials and construction. You can use less pressure in tubulars than clincher tires, as it’s tough to get a pinch flat in tubulars. You can also run a lower pressure in tubeless clinchers, since there’s no tube to get pinched. The option of a lower psi is great for rides that could go off-road. This makes tubular and tubeless clinchers a good bet for road bikes with wider tires, or rides that might take you onto moderate dirt or gravel sections.
Does inner tube material affect psi?
The two most common tube materials, latex and butyl, can be inflated to a similar psi, but there are some variations with porosity and road feel. Butyl holds air better than latex, which is more porous. The higher your psi in a latex tube, the more air you’ll lose as the latex gets stretched. Many riders appreciate the suppleness and bump absorption of latex tubes, but they can lose up to 40 psi throughout the week even without riding, and they often need to be inflated before every ride.
Why does tire pressure affect durability?
Running the wrong tire pressure over an extended period of time can wear out your tire tread unevenly, leading to a shorter life span. Tires that are continually underinflated will wear faster along the outside edge of the tread; tires that are frequently overinflated will wear faster along the middle.
—Maggie Slepian
Tire Pressure with the Pros
➤ Weirdest place you’ve changed a flat?
I once got a flat on my BMX bike on the side of the road in Ulaanbaatar, Mongolia. I didn’t have a tube, but one of the locals had a patch kit and got me rolling again. | Brad Simms, Pro BMX and MTB Athlete with Canyon and Adidas Five Ten
Bike Pump Buyer’s Guide
There’s no single answer for all your tire-pumping needs, but here are your options.
Mini pumps attach to your frame or fit in your pack or jersey pocket and are designed for fixing midride flats. Most lack pressure gauges and attach directly to the valve stem. Our editors recommend Silca’s Tattico Mini Pump, at $70. If you find they’re wearing your arms out before your tire is inflated, consider a CO₂ inflator.
Floor pumps are typically built for high volume or high pressure. High-volume pumps have fatter cylinders and move more air per stroke. A high-volume pump can add three or more psi with every stroke, which means you can quickly pump a mountain bike or fat-bike tire. But “it can be difficult to pump at the higher pressures [between 60 and 80 psi] called for by road bike tires,” says Alex Applegate, director of aftermarket marketing at Trek. That’s because it’s hard to push a large volume of air into a tire that already has a lot of air pressure in it. Some pumps, like the Bontrager Dual Charger Floor Pump ($75) and the CrankBrothers Sterling ($37), can switch between high volume and high pressure.
High-pressure pumps have a thinner cylinder that moves 1/3 to ½ psi per stroke, making it easier to compress air at higher pressures. They’re typically used for road bikes and have a gauge that can go as high as 220 psi. If you’re opting for one over the other, a high-pressure pump can inflate bigger tires; it just requires more strokes.
Booster pumps are designed to seat tubeless tires—a notoriously difficult task for a floor pump—by compressing air in a chamber before blasting it into the wheel to pop the bead of the tire into place. They’re excellent time-savers for home mechanics who do a lot of their own tire swaps. Topeak’s double-chambered Joe Blow Booster pump, which costs around $220, is a solid option.
—Chris Meehan
Our Gear Editor’s Top Picks
Lezyne Pocket Drive Pro HV
When you’re fixing a flat, you want to get back to riding as quickly as possible. Many small pumps are too flexy or simply can’t push enough air to fill high-volume mountain bike and gravel tires. The Lezyne Pocket Drive Pro HV’s aluminum body features a textured handle and Presta- and Schraeder-compatible head and pushes a lot of air for a pump that stows tidily in your pack or bag.
Portland Design Works Shiny Object CO2 Inflator
Nothing beats a CO₂ inflator for quickly filling a tube on the side of the road or trail, but not all CO₂ heads are created equal. Plastic ones can crack; others make it hard to control airflow. The all-aluminum PDW Shiny Object’s is so tiny it fits into even the smallest saddle bags.
If you want to be a tire-pressure pro, a hand gauge is an important tool to have around. The Topeak Smartgauge D2 covers pressures up to 250 psi and fits Presta and Schraeder valves, and the LCD readout makes setting your pressure a snap.
Xiaomi Portable Electric Air Compressor
Perfect for gear bags or anyone tight on space, this palm-sized portable compressor is a favorite of Bicycling’s gear team. USB-rechargeable, it has a bright digital display and is great for topping mountain bike and gravel tires before a ride.
With proper care, a good floor pump will last years (or even decades). Specialized’s Air Tool Comp is one of our favorites for home shop use. It has a stable base and an easy-to-read analog gauge, and it works equally well for airing up high-volume and high-pressure tires.
—Tara Seplavy
Tips for Getting the Most Accurate PSI Reading
The first step in dialing in your pressure is getting an accurate and consistent reading.
“Being off by a psi or two is probably not that big a deal,” says Aaron Chamberlain, an amateur racer, race organizer, and marketing manager for tiremaker Maxxis. “If you’re starting to get 5 or 10 psi off, then yes, it’s going to have a greater impact on your ride quality, on the durability of the tire, and on your rolling resistance.”
Unfortunately, typical pump gauges aren’t very accurate, say both Chamberlain and Alex Applegate, director of aftermarket marketing at Trek. “Most are within 5 percent, and most are accurate in the middle of the range they are designed to pump to,” Applegate says.
“Pro racers largely rely on handheld gauges and consistently use the same one to ensure they know exactly what they can expect of their tires,” says Applegate. Modern dial and digital gauges are generally accurate, and you can buy them with Presta heads and a bleeder valve to drop a psi or two as needed.
Silca Truth Gauge
Digital gauges can offer astounding levels of measurement and accuracy. They typically use a thin diaphragm mounted on a pressure sensor to measure psi. As air hits the diaphragm, the amount of pressure is measured by the deflection of the diaphragm and converted into digital readings of measured pressure.
Silca’s $250 U.S.-made Truth Gauge (see above) is calibrated precisely at 30 psi, according to the company, but at 200 psi, they say accuracy is only reduced by 1 percent. More affordable options include Topeak’s SmartGauge D2 or the $30 SKS Airchecker, which is lauded for its accuracy and easy-to read-display by customers and reviewers, and can measure up to 144 psi.
Mechanical-dial tire-pressure gauges are usually Bourdon tube gauges. Increasing air pressure expands a C-shaped tube, which is connected to a lever that translates the pressure reading to a needle on the display. Some, like Milton's Accu-Gage for road and track bikes ($13), can measure 160 psi or more.
The tiny numbers on the dial are easy to misinterpret, but being off by a couple of psi is acceptable with narrower, high-pressure tires. For mountain bikes and fat-bike tires, where two psi have a noticeable impact on ride quality, it’s better to have a lower-pressure gauge with bigger numbers and marks that are easy to read.
“The quality of the gauge matters more than the style,” says Applegate. “Digital gauges give a very precise reading, but that doesn’t mean they are more accurate.”
—C.M.
Maggie Slepian is a full-time freelance writer in the outdoor industry and has tested gear professionally for almost ten years—she is an avid backpacker, trail runner, bikepacker, and horseback rider and has thru-hiked thousands of miles on the Appalachian, Colorado, and Ouachita trails, along with backcountry travel on terrain including coastal trails, the desert, and high alpine peaks. Maggie has written for New York Magazine, Huffington Post, REI, and Outside. She is a columnist with Backpacker Magazine and is the co-founder of BackpackingRoutes.com. Contact her at MaggieSlepian.com.
Chris Meehan is an internationally published writer, author, and editor with more than two decades of professional experience. He has authored multiple adventure guidebooks with Falcon Guides and his work focusses primarily on the nexus between sustainability and outdoor adventure. He is an experienced gear reviewer, tester, and travel writer who has explored multiple continents.
