Bimota HD B1

Bimota HD B1
Manuals Service Manual




Bimota HD B1

The exquisite HDB1 racer was designed by Massimo Tamburini, one of Bimota’s three founders. The ‘HD’ relates to the 488cc twin motor: in 1976, Harley-Davidson/Aermacchi engines provided power for three separate racing Bimotas. Only one of these HDB1 frames was built though, and Bimota’s association with HD was short-lived. Subsequent racers from the Rimini factory used Yamaha and Suzuki engines. This is a unique model, of great interest for the technical solutions that were employed to construct it. It all began in the mid 1970s, when the Sports Department of Schiranna’s Aermacchi/Harley-Davidson aimed towards the 500 class. After the excellent results obtained on the racetrack with the 2-stroke 250 and 350, a 391 cc was developed which in the hands of Granfranco Bonera proved to be a tough competitor for the Suzuki and MV Agusta 4 cylinders. In light of the prestigious results a full capacity model was developed with a new 2- cylinder engine that was characterized by a 4-carburetor fuel supply.

With this engine a series of about 10 motorcycles were produced for the Sports Department, but thanks to the earlier collaborations with Bimota, an engine was presented to the Rimini based manufacturer. The great designer Massimo Tamburini provided a special frame, with a perimetral structure and high resistance chromo-molybdenum steel tubes. The fork (made from boxed Avional!) is extremely interesting, and extends along the side of the engine to become coaxial with the exit of the pinion in order to not affect the movement of the chain. But the most fascinating feature is certainly the rear suspension that has a cantilever system with a single central cushioning. This is universally employed today but it was a real novelty in 1976. In fact, at the time the only manner to acquire such a component was to enter into the world of Formula 1! The spring is original Bimota and is made from titanium, the cushioning is a Koni, which is identical to, that used on the Ferrari 312/T. Amongst the other original characteristics: the wheel trail can be adjusted through the plates at the head of the fork and the Bimota designed rims are in magnesium. A truly revolutionary Grand Prix bike. Year: 1976 Production: 1 Design: Massimo Tamburini Provenience: CMM Collezione Motociclistica Milanese