Bimota Harley-Davidson 500

 

 

 

The Varese branch of Harley-Davidson had a world champion in the 250 class and had derived a two-cylinder 350 from it. At the beginning of the 1975 season the company put a new 500 into the field.

This was the period in which Phil Read's MV Agusta 500 had serious problems with rear stability, because the rear wheel jumped during braking. Harley-Davidson avoided this problem with its 500 model by mounting a rear disk brake on the end of the transmission pin, a solution that was widely applied to automobiles. Another striking feature of the 500 was the fact that it had four carburetors, even though there were only two cylinders.

This experimental engine was used occasionally on racing motorcycles by Walter Villa, and it was later mounted on the Bimota. That company took over the engine and made a new chassis for it. Bimota gave the

Harley-Davidson 500 the same type of openwork chassis that had been designed for the Suzuki 500. The fork fulcrum was on the axle of the secondary transmission shaft and the rear suspension was "monocross" with a Koni automobile shock absorber. There were replaceable cams on the upper plate of the steering mechanism. The new motorcycle was ridden by Vanes Francini, the official Bimota racer.

Motorcycle: Bimota-Harley-Davidson 500 Manufacturer: Bimota s.n.c, Rimini Type: Racing Year: 1976
Engine: Harley-Davidson two-cylinder, two-stroke, with cross-port distribution. Two carburetors per cylinder. Displacement 500 cc.
Cooling: Water
Transmission: Six-speed block Power: About 90 h.p.
Maximum speed: —
Chassis: Openwork, tubular. Front, telescopic suspension, adjustable; rear, monocross with single central shock absorber
Brakes: Front, double hydraulic disk; rear, single hydraulic disk

1976 – BIMOTA HDB1 – 500

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-carburettor 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.