Bimota HB4 - First Look

Italian Moto2 racer.

Bimota HB4 - First Look

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Bimota is back on track—the racetrack, that is. The last Bimota to tread competition tarmac was the 1000cc V-Twin-powered Suzuki SB8 that in 2000 won one leg of the World Superbike race at Phillip Island in the hands of local Aussie hero Anthony Gobert. Weeks after that surprise victory, Bimota went bankrupt for the third time.

This new Bimota is named HB4, as it’s the fourth Bimota powered by a Honda engine—in this case, the CBR600RR derivative developed for new Moto2 class. The project was put together in a very short time by chief project engineer Andrea Acquaviva and his men. Despite of a complete lack of serious testing, the bike performed well at the recent Italian Grand Prix.

Acquaviva followed a traditional route, using 30mm, 1.5mm-gauge, nickel-chrome-molybdenum tubing. The frame has a linear and rational structure formed by two triangles: The main one runs from the steering head all the way to the rear upper engine mount; the second runs from the main one, just behind the steering head, down to the front engine mount. The two triangulations are tightly interconnected to create a rigid structure. At the rear, the engine is clamped by a pair of typical Bimota-machined aluminum plates.

The chassis of the HB4 is compact, with wheelbase spanning just 53.4 inches. The claimed dry weight of 297 pounds is biased to the front wheel—55/45—with the rider seated well forward. Front-end geometry is adjustable, with a standard setting of a 23.5-degree rake. A brand-new and rather advanced gas-charged 43mm inverted Paioli fork is fitted, while a double-link-actuated Öhlins shock takes care of the rear. Brembo radial-mount four-piston calipers were a natural choice, the 300mm twin “daisy” Braking rotors a bit less so.

The first HB4 that rolled out of Bimota’s race department was sold to the Thai importer for young rider Ratthapark Wilairot. Though unfamiliar with Mugello, Wilairot qualified 24th. On race day, he got a poor start yet was quick to improve his pace, finally lapping within the same second as the leading riders, confirming the quality of the Bimota chassis. Trying to close the gap, Wilairot crashed with six laps remaining in the race.