Royal Enfield collaborates with custom builder to bring racing pedigree to the Guerrilla 450

Royal Enfield have commissioned Madrid-based custom bike builder, XTR Pepo, to produce a one off supermono sportsbike based on their Guerrilla 450, called the GRR.
The custom single was unveiled at the Wheels and Waves festival in June, in Biarritz – a five-day celebration of motorcycles and surf culture that sees several factory-backed customs revealed every year.
The machine is based on Enfield’s Guerrilla 450 launched in 2024, using the same 452cc liquid-cooled, Euro5 compliant engine producing a claimed 39bhp.

It’s the brainchild of single-cylinder enthusiast Pepo Rosell, who wanted the bike to be as light and fast as possible. He managed to shave a claimed 53kg during the build – lowering the stock Guerrilla’s kerb weight of 184kg (with 90% of its fuel) to just 131kg.
Rosell worked with the Italian firm Futura 2000 to 3D model, prototype and build moulds for his custom fibreglass fairings. The fuel tank, seat and tail are monocoque, with a transparent strip in the tank so an eye can be kept on the fuel level.
Elsewhere, the aluminium swingarm is a modified version of that found on the Aprilia RS660 twin-cylinder sportsbike, sprung with a bespoke Nitron R1 rear shock. The front end drops the standard conventional forks and gaiters too, for rebound and compression adjustable 43mm inverted Showa forks.

Staying at the front, the tinted aftermarket front light is heavily inspired by 80s race bikes, including Honda’s RC30.
In addition, the lighter-than-stock Dymag CH3 wheels are an aluminium version of the classic three spokes used by racing legends like Eddie Lawson and should make it more eager to turn.
The wheels are fitted with a pair of Continental ContiSportAttack 2 tyres too, which should provide ample grip for the claimed power and weight of the bike.

Moving backwards, the frame has been modified with a bespoke subframe to accommodate the new single seat and higher tail. It was also designed to support the new, adjustable footpeg placement, making for improved ground clearance when cornering.
Coupled with the addition of clip-on bars, this makes for a far more aggressive riding position than standard.
Providing a little more bark to match the sporty styling is a larger airbox and a 45mm exhaust that sweeps past, instead of under, the engine block with a Spark titanium silencer to cap it off.

The brakes have also been upgraded, sporting twin Discacciati CNC machined calipers at the front with larger, lightened discs.
Whilst striking to look at, the factory-supported GRR build could also hint at future sporting intentions for the 452cc engine platform.
The Indian company has form for teasing future plans via custom builds – seen in the past with concepts like the 2021 SG650 ahead of a production Shotgun 650 cruiser two years later. Whether the same will happen here remains to be seen.