Tire pressure at Unbound Gravel: The secret everyone knows about

by Dan Cavallari

photography by Dan Cavallari


When I ask Amy Charity what tire pressure she’ll run during Unbound Gravel in Emporia, Kansas, she laughs. “You have to ask that, don’t you?” 

I do. She’s running 32 psi.

Amity Rockwell also gives a laugh when I ask about tire pressure, though she’s happy I’ve asked because she’s quick to note that it’s trickier for “small people” like her to choose the right pressure. 

It’s strange to think that gravel racing has now been around long enough to have its own clichés, yet here we are, all having a chuckle about the old tire pressure question. We laugh because we know it matters, but there are so many other things that matter, too. Why tire pressure? 

That comes down to gravel’s growing pains. It wasn’t long ago that gravel was still trying to find itself: 650b or 700c? We asked. Is 35 mm tire width too narrow? Is 50 mm too wide? What about rims? How wide should they be? How deep? Are aero bars okay to use in a gravel race? 

While none of those questions have ultimately been settled, it seems gravel racers have largely settled into trends that indicate where we might be going. A walk through the Unbound pits indicates that 700c seems to have won the battle, for example, and the sweet spot for tire width at most races appears to be in the 40 to 42 mm range.

But tire pressure? Nothing settled about that. Too high and you sacrifice compliance and grip. Too low and you risk a puncture. Same as it ever was, but not the same at all. Gravel’s still finding itself, after all. And sometimes when you’re on a self-exploration, the best thing to do is just ask others who’ve already been down that road.

“What did the other pros say?”

Ian Boswell left a successful career as a WorldTour road racer just before the pandemic hit. Now he has taken up gravel racing and quickly became a favorite for a podium spot at Unbound Gravel, then went on to win it. He knows better than most others in the pro field that fielding questions from curious reporters and even more curious fans comes with the territory. But even he was hesitant to answer the tire pressure question when I ask him ahead of the start what he would run for the race.

“Um, what did the other pros say when you asked them?” He says in response. I tell him most were in the 32 psi to 40 psi range. “Yeah, I’ll go with 40,” he says, only half-joking. It feels a bit like I’m back at Paris-Roubaix, where riders and mechanics are even more cagey, hiding pressure gauges as they pump up tires before the start.

This year’s crop of contenders included several former WorldTour pros. One of the most exciting aspects of this transition is watching these riders, who are used to a team car following them and a team of mechanics setting up their bikes, figuring it all out on their own. Most of them already know enough to do more than the basics, but hey, it’s been a while.

Laurens ten Dam, who went on to finish second, says he learned from other pros who had already made the leap to gravel to get a handle on what he would need to be able to do should he run into trouble out on the course. He and Thomas Dekker plugged a tire on a recon ride the day before Unbound Gravel, and while it wasn’t his first time plugging a tire, the process is still new enough to Ten Dam to be a bit nerve-racking. 

Pete Stetina is perhaps more sure of himself. After leaving the WorldTour in 2019, Stetina has become a regular favorite at just about every gravel race he enters. His Canyon mechanic, “Big Tall Wayne,” says Stetina intends to run 32 psi for Unbound. “I don’t think tire pressure is a secret,” he says. Then, after a pause, “Is it?” 

Stetina’s IRCs had 32 psi in them.

Ignorance is bliss

Allison Tetrick, who has won Unbound before and has come close a few times on top of that, is an admitted data nerd. When she raced on the road, she regularly obsessed about her tire pressure and tailored it to whatever course she might be on. 

But for her gravel races, she has taken an “ignorance is bliss” approach to clear out some of the nervous clutter in her head before a race. She trusts her partner, Blaize Baehrens, to get her ride dialed pre-race. All Tetrick knows is her pressure will be somewhere in the 30-40 psi range — and not knowing is just fine by her.  Focus and calm is far more important than one or two psi. 

The obsession with tire pressure is perhaps an indication that gravel is growing up. The number of WorldTour pros showing up at gravel races is ever-increasing; the gear changes constantly, with improvements to weight, durability, functionality, and adaptability. The tires have gotten lighter, stronger, more supple, more capable of tackling gnarly roads and trails. Tire liners have become the puncture protection of choice for truly rugged courses. Technology is on the gravel racer’s side. 

But I have to ask you: What pressure you runnin’? 

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