Back at EICMA 2019, just before COVID (remember those carefree days?), Bimota unveiled its KB4 prototype. Since then, the bike has been in quarantine like the rest of us, until EICMA 2021, about a day ago. Breathe easily: the bike is alive and ready to ride.
The KB4 was one of the centerpieces of the show, refined, elegant and slightly retro, especially in the KB4-RC edition. Bimota Managing Director Pierluigi Marconi, the man who created the Tesi chassis concept, surprised audiences by unveiling a machine that departs from Bimota’s ultra-sport tradition and emphasizes supreme handling. The idea behind the KB4: Pair the relatively smooth-mannered Kawasaki Ninja 1000SX inline-four with a nimble chassis, then wrap it in distinctive style, all with flawless execution.
The 142 hp Ninja powertrain bolts into a tubular steel trellis frame with a structure inspired by classic Bimota creations. Machined aluminum billet components define the construction; the swingarm is machined from billet aluminum, as is the rear shock linkage. The suspension components are all Öhlins, a TTX 36 shock at the rear and a 43mm FG R&T 43 NIX 30 fork up front. The triple clamps are, of course, also machined billet aluminum, as are the associated footrests and levers. Carbon fiber bodywork elements, as well as the genuine leather-trimmed seat, further underline the refined nature of the whole. Everything is pure high-end execution.
Lightweight, powerful, but above all compact
Pierluigi Marconi, together with highly experienced chief stylist Enrico Borghesan, focused on making the bike accessible for real-world riding, paying special attention to ride quality and comfort. The seat height has been kept at a very human level of 31.5 to 31.8 inches in order to provide a center of gravity which must be among the lowest in the field of contemporary sport motorcycles. The bike is compact not only in height, but in wheelbase; at 54.7 inches, it is only 0.5 inch taller than a Honda CBR300R. To move the front wheel back as far as possible, Marconi placed the radiator between the rear part of the seat and the rear tire and added a cooling fan, the same solution as on the Benelli 900 Tornado. The front features a state-of-the-art 24-degree steering axle with 101mm (4.0 inches) of drag.
The Bimota KB4 and KB4 RC (the “RC” stands for Race Cafè) run on Pirelli Diablo Sport radials, a 120 / 70-17 at the front and 190 / 50-17 at the rear. Brembo supplies the braking system in the proven combination of two 320mm front rotors and four-piston calipers, combined with a single 220mm rear disc and two-piston caliper. The dry weight is moderate at 417 pounds.