CZ - 250 typ 856 & 300cc typ 857
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CZ D2-492-65-13
Photo ou archives : D. Ganneau
6513

Capacity : 250
Model : 250 typ 856 & 300cc typ 857
Production : 1962 - 1966
Category : (R) Racing
   

CZ

250 typ 857 -1962

The single's last stand

Around 1960, Czechoslovakia still retained its full technical brilliance, and Jaroslav Walter managed to convince the CZ factory to go back to track racing after its great success in motocross. It was a significant step, since the company had rested on its laurels after the twin-cam vertical singles of 1954 and 1955. This new generation consisted of a 125 (Typ 855), a 175 (Typ 856) and a 250 (Typ 857). The new engines were still singles but were now forward-inclined, and the intake camshaft drove the exhaust camshaft directly.

Record of Success

The 250 was successfull in racing behind the Iron Curtain. Ridden by Stanislav Malina, it won three GPs in 1963 and one in 1964. In the World 250 Championship, its highest finishes were two fourth places in East Germany in 1965 and a first-place win in Stastny, Finland in 1966.

Twin Exhausts

A 350cc version - recognizable by its twin exhausts - actually displaced 293cc (72x72 mm) as first produced and was then taken to 318cc. It was also raced occasionally but had only a single win, in Malina, Italy in 1964. The Japanese had become too dominant, with their superpowerful multi-cylinders and their enormous competition budgets. In 1964, the Typ 858 four-stroke twin replaced the 125, while a three-valve 350 (Typ 859) succeeded the 250 Typ 857 in 1966. An insufficient budget meant that these machines could do little better than their predecessors on their rare excursions to the West.

SPECIFICATIONS

Engine: 246cc (70x64mm) air-cooled singlecylinder four-stroke; coil ignition

Power Rating: 37 hp@ 11,000 rpm

Valves: twin overhead-camshafts driven by shaft-and-bevel

Fuel System: carburetor

Transmission: 7-speed, chain final drive

Suspension: telescopic forks (front); swing arm (rear)

Brakes: drum (front & rear)

Wheels: 3.00x18 inch (front); 3.50xl8 inch (rear)

Weight: 247 lb

Maximum Speed: 131 mph

 

The 250 Typ 857s two-stage valve gear, with the exhaust camshaft driving the intake camshaft, was the ballmark of the racing CZs of the 1960s.


Motorcycle encyclopedia Moto Passion, realised by François-Marie Dumas, include almost 2000 photos presented with an exhaustive history of the motorcycles exhibited.

This unique collection has been realised with the participation of many specialists. With many thanks in particular to Yves Campion, Michael Dregni, Didier Ganneau, Jean Goyard, Helmut Krackowizer, Michel Montange, Christian Rey, Bernard Salvat, Mick Woollett, etc

One can order here

  • Original cards on paper (in french)
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