A few months back, my friend and fellow bicycle enthusiast Eric prepared for his first 100-mile bike ride. Concerned about how sore he’d be afterward, he wondered what he could do to improve his ride.
As a convert to the Church of Fat Tires, I was excited to share with him an idea I’d learned from other cyclists: Cram on the fattest soft-sided tires that will fit on your bike, then inflate them to a pressure that will seem surprisingly low.
I've been a volunteer bike mechanic in Seattle for almost 10 years and have gently modified my own midrange 1988 Peugeot into something modern and capable. Yet nothing prepared me for the impact of fat tires with pliable (aka “supple”) sidewalls and inflating them to a pressure much lower than what I was used to. I remember my amazement riding down a big hill, listening to the different sound my tires made and experiencing the sure and solid feeling the bike suddenly had. It felt grippier, more comfortable, less twitchy, and maybe even faster. In car terms, it was like going from a well-cared-for old Camry to a modern sport truck. It was exhilarating.
“Tires are probably the single most important component on your bike and the only part that touches the ground,” says Russ Roca, who has 175,000 subscribers on his YouTube channel, The Path Less Pedaled, which focuses on enjoyment over speed and typically spotlights bikes that can ride on both gravel and pavement. “A wider tire means more volume and built-in suspension. It makes the bike feel more stable.”
Roca says wider tires are just more fun. “You’re not being jarred to death. You're not bouncing off of every rock and pothole. They are the most noticeable upgrade you can make to your bike."
This made sense, and I’d learn that not having my wrists and keister being jarred helped keep them from getting sore on longer rides.
Yet somehow, fat tires still feel like a bit of a secret. Us cyclists put pads in our shorts and buy heavy suspension systems for off-road bikes, but we're somehow reluctant to experiment with the part of the bike that actually touches the road to help make for a nicer ride. Big, global bicycle brands still seem unsure about embracing the trend, perhaps trying to ensure that you buy a skinnier-tired road ride and wider-tired gravel bike instead of one “all-road” bike that can do both.
“Cycling has a lot of tradition, and sometimes we do things because they’ve always been done that way,” says Roca. “The industry says lighter equals good, which is easy to explain and market, but selling on ride feel and supple tires is more amorphous.”
Plus, wide tires are relatively new to the market. Models with supple sidewalls made with high-thread-count fabric and a coat of rubber thick enough to protect the weave but thin enough to let the tire be plenty flexible have become widely available only in the last decade. Throw a pandemic in there, and an industry that's long on inventory, and you can understand why adoption has not been widespread.
Hidden in the buyers’ reluctance is the belief that a wider, softer tire is slower than a high-pressure skinny one, that the fatter tire weighs more and has more rolling resistance. But that's not always the case.
Last year, I hit a, um, milestone birthday and bought myself a fancy new all-road bike from Rivendell Bicycle Works. It accommodates tires north of 40 millimeters wide. (I currently use 38s.) The frame is made of steel, and the bike is not particularly light, but I love how it feels and how it encourages me to ride as much as possible—and fast. A lot of that has to do with the tires.
Toward the end of a summer when I rode a lot, I ended up at a stoplight next to a spandex-clad racer on a skinny-tire bike. When the light turned green he shot off, and I thought: What the hell.
My takeoff didn't match his, but once we were up to speed, I kept up with him at a sustainable pace and loved the thought that this may have perplexed him. Over the course of a couple of miles, I was right there, a few bike lengths back, keeping up as we sped north along the tree-lined Burke Gilman Trail. I was in my groove. By the time we approached my destination, he'd pulled away by maybe 100 feet, and considering how happy I was, I was pretty fine with that.
Jan Heine is a fat-tire evangelist. He’s also a bicycle manufacturer, a long-distance and gravel rider, a former racer, the author of The All-Road Bike Revolution, and the editor in chief of Bicycle Quarterly magazine, which could be described as glossy bike-porn mag with surprisingly hefty portions of cycling science. He also put his money where his mouth was, founding tire manufacturer Compass Cycles in the mid-2000s.
“I kept telling people they should make tires like this,” Heine says, “but realized I should just do it myself.” Heine eventually folded his tire business into his high-end bike and component brand, René Herse.
“I really admire someone like Jan who's doing the research,” says Steve Gadingan, the recycle-and-reuse director at Bike Works, the Seattle nonprofit where I volunteer. Gadingan noted that while Heine both writes about tires and sells them, he is off on his own in an industry dominated by giants, using his resources to methodically test, learn, and make bikes better. “He's like the guy from Moneyball.”
Heine and the Bicycle Quarterly team are known for devising ways to test the effects of bicycle geometry, frame flex, aerodynamics, and the rolling resistance of tires. One notable 2006 test picked up on a 1960s US Army experiment where the military learned how much extra energy tanks needed to expend to maneuver over rough surfaces. For his test, Heine rode a bicycle with 26-millimeter tires on an empty highway, tracking how much energy he expended riding 25 kilometers per hour on the road's rumble strip, then how much harder he needed to work riding a bike with high-pressure tires. More than twice as much! Dropping the pressure in the tires made the ride faster and more comfortable, and it didn't wipe him out. At the right pressure, the right tire glides right over the bumps, absorbing them instead of pummeling you, making a long ride notably more comfortable.
Later, Heine’s team would tease these findings out, coming to understand that unless you're riding on perfectly smooth roads, high pressure can slow you down, particularly over time. A wider tire—the René Herse line starts at 26 mm and goes up to 55 mm, which makes for a solid-enough definition of “wide” in 2024—can run at a relatively low pressure and smooth out a ride, making it faster.
If you extended that idea out a bit, what are most roads and gravel paths but stretched-out rumble strips? Bicycle Quarterly has even come out with a tire-pressure calculator where you plug in the tire size and the combined weight of you and your bike and it spits out a range of pressures to try.
"Higher tire pressures make the bike vibrate faster without actually going any faster," Heine says in Revolution.
When we met at Lighthouse Roasters in Seattle, where Heine is based, he rode a modern carbon fiber, all-road bike with fat and smooth 48-mm tires. He picked up the vibration topic where his book left off.
"The faster you go, the more vibrations increase. If you go one meter per second versus two, that's twice as much vibration for your body to absorb," he said, sipping a hot chocolate. “If you move vibration through a hard, overinflated tire, it creates friction in the body. You get really tired, and that costs you speed. Racing trucks like you see in the Baja 1000 have water-cooled shocks to dissipate the heat they create. You don't want that in the human body.”
Width also matters, because tires create a cushion of air to ride on, and narrower tires can't be deflated enough to provide cushioning without bottoming out first. Get wide, soft tires tuned just right, Heine says, and speed can actually increase about 20 percent faster than what you do on skinny, hard tires.
Part of that “just right” tuning involves finding tires with the right amount of softness in the sidewall. Roca, who promotes “the supple life” on his YouTube channel, has a video in which he holds a big, supple tire up to the camera. Lacking the sidewall stiffness common in high-pressure tires, the fat tire droops right out of the frame.
To try the supple life for yourself, you don’t necessarily need a new bike. Instead, you could put the fattest tires possible on the bike you already own. For advice on how to do that, I talked to Steve Gadingan.
Along with being a professional bicycle mechanic, Gadingan is a self-described tinkerer who, as we sat to talk, started listing all of his bikes, then got self-conscious when he hit the fourth one in a longer list. He uses 48-mm René Herse tires on several of them.
"A lot of people don't notice tires and ride on a heavy tire that won't get a flat. But the right tire changes your attitude and makes you want to move more," he said, noting other favorites from brands like Ultradynamico and Maxxis, along with the supple and affordable offerings from Panaracer and Schwalbe. “It's like going from black and white to color.”
To convert a bike, he suggested bringing it to a shop where a knowledgeable mechanic can determine what width of tire can fit in your bike frame. If you do it yourself, you'll want to measure how much space you have, though a fair amount of trial and error may be required. As for older bikes that are particularly well-suited for this kind of conversion, he has a few favorites. On the gravel-friendly side, Gadingan likes steel bikes from the ’80s and ’90s made by Specialized, like the Stumpjumper, Hardrock, and Rockhopper, along with Trek models like the Singletrack and Multitrack. Road bikes are trickier, as they tend to have less room for a wide tire, but he particularly likes Miyatas from the late ’70s and early ’80s, along with other Japanese bikes of that era, yet many bikes like my old Peugeot have at least enough room to squeeze in tires that will make a notable difference.
If you want a new bike and a good intro to wide tires, he likes the frames made by Surly, which have the words “Fatties Fit Fine” tattooed right on them. But he really encourages you to soup up your current ride.
"You don't have to get a new bike," Gadingan says. “Ride what you've got … The best bike is the one you love.”
