Pepo Rosell, better known as XTR Pepo, is a force of nature. He originally burst onto the scene with his specialist custom workshop, Radical Ducati, before taking a break and relaunching as a solo act. Often inspired by classic endurance racers, Pepo’s bikes convey a sense of speed—with a hint of eccentricity.
Pepo’s portfolio is dripping with exotic twin-cylinder Italian machines, but he’s just as adept at applying his talents to smaller bikes. He’s just buttoned up this Royal Enfield Guerrilla 450, and it’s every bit as radical as you’d expect an XTR Pepo motorcycle to be.
In stock form, the Guerrilla 450 is a peppy single-cylinder roadster with a look that deviates from the Indian marque’s traditional aesthetic. But in the hands of Pepo, it’s a feisty supermono racer with tons of attitude.
“I like singles very much,” says Pepo. “So when Royal Enfield proposed that I work with the Guerrilla, I saw the opportunity to make a super-single with no compromise—a race bike for track and road use.”
Pepo started with a 2024-model Royal Enfield Guerrilla 450, but little remains of the original bike beyond its frame and engine. The motor’s still stock inside, but it’s been liberated somewhat, courtesy of a deft airbox mod. Gasses are expelled via a 45 mm exhaust header, built by Xpipe, and a titanium Spark muffler.
Moving to the chassis, Pepo binned the factory subframe and fabricated a new one. The new unit kicks the tailpiece up at a far sharper angle than before, and features integrated mounts for the bike’s new rear-set footpegs.
The Royal Enfield Guerrilla 450 also sports upgraded running gear at both ends. The front forks are Showa units from an Aprilia RSV 1000, held in place by CNC-machined yokes. A modified Aprilia RS 660 swingarm does duty at the back, hooked up to a custom-built Nitron shock.
Pepo also specced the Royal Enfield with forged aluminum Dymag wheels, wrapped in Continental Conti Road Attack 2 tires. The twin front brakes use Discacciati calipers and 320 mm floating discs, while the rear brake uses a Brembo caliper (also lifted from an Aprilia).
The Guerilla’s sharp new bodywork is quintessential XTR Pepo fare. To create it, Pepo worked closely with Futura 22, a design firm in Turin, Italy, and digital modeler Alberto Caimi. Working from Pepo’s initial renders, the team fine-tuned the overall design before 3D-printing molds for everything.
The final parts were shaped out of fiberglass using these molds. The setup includes a low-slung front fairing on a bespoke mounting system, a sculpted fuel tank, and a boxy tail section with a slim racing pad. A clear strip on the side of the fuel tank acts as a fuel gauge, while the rear cowl has a removable panel that offers quick access to the bike’s wiring.
An offset headlight adds a hint of retro endurance racing style, while a scooped belly pan drives the point home. The cockpit features clip-ons, Domino grips, Discacciati levers, and the OEM speedo, which has been remounted on a custom bracket.
Then there’s the Guerilla 450’s energetic livery—a heady mix of bold colors, chunky graphics, and sponsor logos, complemented by a bright red frame and a handful of carbon fiber accents.
Pepo considers himself retired these days, so this might be one of the last bikes we see from him, and more’s the pity. This plucky Royal Enfield Guerilla 450 racer is proof that the man’s ability hasn’t waned one bit—and it makes a strong case for a Guerilla 450 spec series, too.
XTR Pepo Instagram | Images by Matt Sills
