Gravel has always existed outside of the law
At the frontier where road cycling's aesthetic meets off-road ambition, the UCI is quietly deliberating whether to close a door it only recently opened elsewhere. Having sanctioned 32-inch wheels for mountain biking, the governing body now appears poised to prohibit them in gravel racing — not on grounds of safety or fairness, but because drop bars evoke road cycling, and road cycling has always lived under stricter equipment rules. It is a moment that asks an older question: who gets to define what a discipline is, and whether the map drawn by regulators will ever fully match the terrain riders actually cross.
- Riders have already raced 32-inch wheels at Unbound, and a World Cup podium in mountain biking proves the technology is no longer theoretical — the innovation is here, now, demanding a regulatory answer.
- The UCI's silence is itself a kind of pressure: no public statement, no response to press inquiries, yet industry sources confirm the conversations are very much alive behind closed doors.
- Trek's R&D chief Travis Brown puts it plainly — his money is on a ban, because the UCI sees gravel's drop bars and concludes the discipline belongs in road cycling's regulatory family, not mountain biking's.
- The logic troubles many in the industry: gravel bikes may look like road bikes, but they ride terrain that road bikes were never built for, and aesthetic similarity feels like a thin basis for restricting equipment innovation.
- A ban would mark a significant shift — the UCI formally extending its traditional authority into a discipline that grew up deliberately outside its orbit, turning gravel's regulatory gray zone into governed territory.
The 32-inch wheel has already arrived in gravel racing. Riders like Cam Jones and Robin Gemperle brought them to Unbound, and Thömus Maxon became the first team to podium on one at an XC World Cup — evidence that the technology performs at the highest level. Yet the UCI, which officially approved 32-inch wheels for mountain biking last year, appears to be moving toward a different decision for gravel.
According to multiple industry sources, the governing body is actively considering a ban on 32-inch wheels in drop-bar racing, placing them alongside other already-prohibited equipment: narrow handlebars, long socks, wheels deeper than 66 millimeters. The UCI has not publicly confirmed these discussions and did not respond to requests for comment. But Travis Brown, head of R&D at Trek, confirmed the debate is real. His assessment is direct: he expects the UCI to eliminate the option in gravel, because the organization perceives gravel — by virtue of its drop bars — as categorically close to road cycling.
That reasoning exposes something fundamental about how the UCI maps cycling's disciplines. Mountain biking has always operated in its own regulatory world. Gravel occupies murkier ground, borrowing road cycling's aesthetic while venturing into terrain road bikes were never designed for. The UCI appears to treat the handlebar shape as the decisive boundary.
What gives this moment its weight is gravel's history as a regulatory frontier. Events like Unbound grew up largely outside the UCI's formal reach, giving riders and manufacturers room to experiment freely. A ban on 32-inch wheels would represent the governing body drawing a firm line into that open space — whether that reads as necessary order or unnecessary constraint depends entirely on where you stand in the industry.
The big wheel is coming to gravel racing, and the UCI might be about to slam the door before it fully arrives. Riders like Cam Jones and Robin Gemperle have already taken 32-inch wheels to the Unbound 200 and Unbound XL events. BMC unveiled a prototype XC bike fitted with them in Andorra. Most tellingly, Thömus Maxon became the first team to both race and podium on a 32-inch mountain bike at an XC World Cup—proof that the technology works at the highest competitive level.
Yet the regulatory path forward appears to be splitting. Last year, the UCI officially blessed 32-inch wheels for mountain biking, opening the door to innovation in that discipline. But gravel racing, it seems, will face a different calculus. According to multiple industry sources, the UCI is actively considering whether to ban 32-inch wheels from drop-bar racing entirely, lumping them alongside other prohibited equipment: narrow handlebars, long socks, and wheels deeper than 66 millimeters.
The UCI has not publicly acknowledged these discussions, and the organization did not respond to requests for comment. But the conversation is real and ongoing between the governing body and the industry. Travis Brown, who heads research and development at Trek, confirmed the debate is happening. "The discussion is currently happening between the industry and UCI," he said. Brown's own read on where this lands is blunt: "It is speculative at this point, but my money would be on them eliminating the option in gravel, as in road, as they perceive category proximity of the two disciplines based on curly bars."
That reasoning—that gravel bikes with drop bars are too close to road bikes to warrant the same equipment freedoms as mountain bikes—reveals something about how the UCI thinks about cycling's categories. Mountain biking has always had its own regulatory universe. Gravel, by contrast, lives in a murkier space, borrowing the drop-bar aesthetic from road cycling while operating in terrain that road bikes were never designed for. The UCI appears to view that aesthetic similarity as the decisive factor.
What makes this moment interesting is that gravel has historically existed in a kind of regulatory gray zone. The discipline emerged and grew largely outside the UCI's formal purview, with events like Unbound operating under their own rules. Riders and manufacturers have had room to experiment. A ban on 32-inch wheels would represent the UCI extending its traditional control into a space that has, until recently, felt more like the wild frontier of cycling. Whether that's a necessary standardization or an unnecessary constraint depends entirely on who you ask—and which side of the industry you're on.
Notable Quotes
The discussion is currently happening between the industry and UCI. My money would be on them eliminating the option in gravel, as they perceive category proximity of the two disciplines based on curly bars.— Travis Brown, head of R&D at Trek
The Hearth Conversation Another angle on the story
Why does the UCI care about wheel size in gravel if the discipline has always been more freewheeling than road racing?
Because gravel uses drop bars, and the UCI sees drop bars as road cycling's signature. Once you have that geometry, the UCI wants to apply road cycling's rules. It's about category control, not really about what works best on dirt.
But mountain bikes got the green light for 32-inch wheels. What's different there?
Mountain bikes have their own regulatory world. They've always been separate from road. Gravel is the awkward middle child—it borrows road's bars but rides on terrain road bikes can't handle. The UCI doesn't know quite what to do with it, so they're defaulting to treating it like road.
Has the UCI actually said they're banning them, or is this still theoretical?
Still theoretical. They haven't commented publicly at all. But industry sources say the conversations are real and ongoing. Travis Brown at Trek thinks a ban is likely, but nothing's official yet.
What would a ban actually prevent? Are riders already using 32-inch wheels in gravel racing?
Some are, yes—Cam Jones and Robin Gemperle raced them at Unbound. But it's still early. A ban would stop the technology from becoming standard before it really takes hold.
Does gravel racing actually need the UCI's permission to exist?
Not technically. Gravel events like Unbound have their own rules. But if the UCI bans the wheels, it affects any gravel race that wants UCI sanction or recognition. That's where the real power lies.