The Bimota HB1 was the first bike to ever wear the now-legendary Bimota badge on its tank, and it came about by accident. And I mean that literally. Massimo Tamburini crashed his Honda CB750 in September 1972 at the Misano racetrack – the accident left him with three broken ribs and plenty of time to think about what had gone wrong.
Tamburini realised that although the Japanese CB750 engine was fantastic, the frame and suspension was poorly designed and incapable of handling the power produced by the 750cc inline-4. A plan began to form with the goals of reducing weight, improving rigidity, and lowering the centre of gravity. Tamburini chose to use the engine as a stressed member, with an entirely new tubular steel frame carefully designed to maximise the performance of the new suspension – including a new box-section swing arm.
Ceriani forks were fitted up front with twin Marzocchi shocks on the back, new alloy wheels were used to reduce unsprung weight, triple discs aided with braking, an oil cooler was fitted to keep the engine temperatures within optimal range even when being ridden hard, and an entirely new fuel tank, seat, rear cowl, and fenders were designed.
Even without any engine performance enhancements, the new Bimota HB1 was capable of far outpacing an original factory-spec Honda CB750. Bimota didn’t originally sell complete motorcycles – they sold kits comprised of a frame, bodywork, suspension, and brakes, and buyers were then left to their own devices to construct the bike.
Including the first prototype, just 10 HB1s were built in the early 1970s, and it’s thought that just 4 have survived to the modern day.
As with other iconic motorcycle frames like the Norton Featherbed, there is significant interest from custom motorcycle builders in modern frames built to exact original standards – especially with frames like the HB1 which were produced in such low numbers originally, making it all but impossible to buy an original ’70s-era example.
The solution to this is to reverse engineer the original frame, and then reverse engineer the bodywork, meaning all you need is an original engine and suspension before you’re on your way to having an HB1 that’s indistinguishable from an original.
The bike you see here was actually built in 2016 by the team at Husky Restoration – with the guys over at Framecrafters building the chassis. An all-new Bimota HB1 frame was created from scratch, and a new fuel tank, seat and rear cowling where moulded from carbon fibre – a big step up from the fibreglass originals.
In the spirit of originality, Rob at Husky Restoration fitted original Marzocchi shocks and Ceriani forks, with Brembo brakes, and Excel aluminium rims. A new MotoGadget M-Unit has been installed with an entirely new, custom wiring loom and an Anti-Gravity lithium battery – meaning this bike will be far easier to work on than an original.
The completed bike is a significant accomplishment, and the popularity of the original SOHC CB750 could see a significant uptick in interest in bespoke HB1 frames. If you’d like to read more about this bike or enquire after getting your own – you can click here to visit Husky Restoration.