You might not have heard of Blacktrack Motors, a custom builder based out of Luxembourg, but that might be about to change. The group's latest build takes Harley-Davidson's beastly Fat Bob and recasts it as—wait for it—a slim and trim café racer. And you know what? This skinnier Bob is a real stunner.

Blacktrack Motors BT-03
Talk about a crash diet. Beneath the BT-03’s lovely bespoke bodywork and premium componentry lies a Harley Fat Bob, Milwaukee-Eight 114 engine and all.Sacha Lakic

The Blacktrack BT-03 looks like the epitome of a modern-day café racer, and the inspiration behind it, says Blacktrack founder and designer Sacha Lakic, is “the Harley-Davidson XLCR.” “Produced between 1977 and 1979, it was the only café racer in the history of Harley-Davidson. I was spellbound every time I saw one on the streets of Paris.”

Blacktrack Motors BT-03
Although it’s inspired by Harley’s XLCR from the ’70s, the BT-03 rocks its own modern aesthetic. That front cowling and fuel tank are one-off composite pieces that elevate it to another level.Sacha Lakic

But clearly the BT-03 isn’t just a straight replica of the XLCR. You might spot hints of the XLCR's DNA in the BT-03’s angular stretched fuel tank and tailsection and seven-spoke wheels, but the Blacktrack bike is far more sport-focused, with a contemporary aesthetic and stance that give it an unmistakable race vibe.

Blacktrack Motors BT-03
With a solo seat, clip-ons, rearset controls, and an emphasis on the engine, there’s no mistaking the bike’s sporty intent. The rear subframe is a custom design by Blacktrack.Sacha Lakic

With the limited-edition BT-03, Blacktrack continues to mine the past for inspiration as it has on previous builds, which were also sporty designs. The shop's first bike, the BT-01, was based on a 1980s-era Honda CX500—a practical ride appreciated more for reliability than styling. Blacktrack clapped on all-new bodywork to sleeken the aesthetic, and chose components to improve performance and weight.

With the BT-02, Blacktrack went bigger and bolder, starting with a new Triumph Thruxton and bestowing it with iconic Norton Manx styling. It too featured bespoke bodywork and a custom exhaust to yield a nostalgic sound. As you might’ve guessed by now, the Blacktrack Motors business model is building exclusive performance-based café racers.

Blacktrack Motors BT-03
The cockpit is café-racer-ready, with ABM Sport handlebars, Beringer levers, and master cylinders and grips by Rizoma.Sacha Lakic

For the BT-03, a burly Harley-Davidson Fat Bob was chosen as the donor, 114ci Milwaukee-Eight powerplant and all. But, frankly, this Softail just doesn’t seem like a natural fit for a racy bike, so…why?

Lakic explains, "The Fat Bob is the most exciting Harley to ride. The wheelbase is certainly a bit long, but the geometry is well thought out, and allows you to roll turns faster than any other Harley so far." Not only that, but there's not much left of the original Fat Bob anyway; Blacktrack kept only the motor, transmission, and frame—replacing everything else with custom and upgraded components to improve looks, reduce weight, and improve handling.

Every aluminium part is designed in the Blacktrack Motors studio and then CNC-machined by a trusted technical partner. A crucial point is the rear frame assembly—which acts as an interface between the Bob’s original frame and the BT-03’s custom bodywork. Composite parts include the front fairing, front fender, fuel tank, tailsection, and a cover plate for the rear shock.

The Fat Bob’s main frame and geometry remain unchanged, but Öhlins suspension, Dymag forged aluminium wheels, and Beringer brakes all make the scene here. Blacktrack Motors also installed a performance air filter and a custom-built stainless steel exhaust system with fuel mapping to match.

Blacktrack Motors BT-03
To match the BT-03’s sporting intent, Blacktrack upgraded suspension to Öhlins components, swapped in Beringer brakes, and crafted custom stainless steel headers.Sacha Lakic

Replacing the weighty OEM parts meant the Fat Bob’s unsprung mass was reduced and the BT-03’s overall dry weight came down to 546 pounds, giving it an excellent power to weight ratio.

So can you buy one? Yes—if your wallet can withstand the hit. Past Blacktrack builds went for somewhere north of $50K, and we’d expect this one to be more as only four will be made.

Blacktrack Motors BT-03 seat
Premium leather covers the solo saddle, which itself sits on a Blacktrack-built tailsection.Sacha Lakic

Spec Sheet

Base model: Harley-Davidson Softail Fat Bob 114
Engine: Milwaukee-Eight 114ci (1,868cc)
Main frame: Harley-Davidson Softail
Rear subframe: Blacktrack Motors
Triple clamps: Blacktrack Motors
Front suspension: Öhlins FG424
Rear suspension: Öhlins HD 501
Front wheel: Dymag UP7X custom forged aluminum
Rear wheel: Dymag UP7X custom forged aluminum
Front tire: Michelin Power RS 120/70ZR17
Rear tire: Michelin Power RS 190/50ZR17
Front brakes: Beringer Aerotec Radial 4-piston, Beringer Aeronal 320mm discs
Rear brakes: Beringer Aerotec Axial 4-piston, Beringer Aeronal 290mm disc
Front fairing: Blacktrack Motors
Front fender: Blacktrack Motors
Fuel tank: Blacktrack Motors
Tailsection: Blacktrack Motors
Seat: Blacktrack Motors, leather cover
Handlebar: ABM MultiClip Sport 1 in.
Controls: Beringer levers and master cylinders
Headlight: Highsider Type-6
Foot controls: Blacktrack Motors
Exhaust headers: Blacktrack Motors twin stainless steel system
Exhaust mufflers: Jekill & Hyde Shorty
Dry Weight: 546 lb.
Lean angle: 36° left and right