Back during EICMA 2019, just before COVID (remember those carefree days?), Bimota unveiled its prototype KB4. Since then the bike has remained in quarantine like the rest of us—until EICMA 2021, a day or so ago. Breathe easy: The bike is alive, well, and ready to roll.
The KB4 was one of the centerpieces of the show, refined, elegant, and slightly retro, particularly in the KB4-RC edition. Bimota General Manager Pierluigi Marconi, the man who created the Tesi chassis concept, surprised the audience by unveiling a machine which departs from the Bimota’s ultrasport tradition and which focuses on supreme handling ease. The idea behind the KB4: Mate the relatively mild-mannered Kawasaki Ninja 1000SX inline-four to an agile chassis, then wrap it in a distinctive style, all with impeccable execution.
The 142 hp Ninja powerplant bolts into a steel-tube trellis frame featuring a structure inspired by Bimota’s classic past creations. Machined aluminum billet components define the construction; the swingarm is machined from aluminum billet, as is the rear shock linkage. Suspension components are all Öhlins, a TTX 36 shock in the rear and a 43mm FG R&T 43 NIX 30 fork up front. The triple clamps are, naturally, machined aluminum billet as well, as are the footpegs and related levers. Carbon fiber body elements, together with the genuine-leather-trimmed seat, further underscore the refined nature of the overall package. It’s all pure, high-end finesse in execution.
Pierluigi Marconi, along with highly experienced chief stylist Enrico Borghesan, have concentrated on making the bike accessible for real-world riding, paying particular attention to handling quality and comfort. Seat height has been kept to a very human 31.5–31.8 inches in order to offer a center of gravity which has to be among the lowest in the contemporary sportbike domain. The motorcycle is compact not only in height, but in wheelbase; at 54.7 inches, it’s only 0.5 inch longer than a Honda CBR300R. To move the front wheel as far back as possible, Marconi located the radiator between the rear section of the seat and the rear tire and added a cooling fan, the same solution as on the Benelli 900 Tornado. The front end features a state-of-the-art 24-degree steering axis with 101mm (4.0 inches) of trail.
The Bimota KB4 and KB4 RC (the “RC” stands for Race Cafè) roll on Pirelli Diablo Sport radials, a 120/70-17 front and 190/50-17 rear. Brembo provides the braking system in the proven combination of twin 320mm front rotors and four-piston calipers, teamed with a single 220mm rear disc and a two-piston caliper. Dry weight is a moderate 417 pounds.