Same old story – innovative Easter Bloc race bike let down by dodgy metallurgy
This innovative V4 could have been one of the major GP bikes of the ’60s and ’70s with better quality materials and more financial investment
Ceska Zbrojovka, better known as CZ, was a Czech company which was originally a subsidiary of Skoda Works, based in Strakonice and producing car parts and firearms as well as motorcycles.
This is one of two CZ Type 860 V4 Grand Prix road racers known to exist in this 420cc version (actual capacity 418cc: 55mm bore x 44mm stroke).
The 90°, 16-valve, double-overheadcam design started out as in 350cc form (50mm bore x 44mm stroke) in 1965, created by CZ engineer Frantisek Pudil. But thanks to political intervention (the industry was state-controlled) the first bike only ran in 1969, the day before that year’s Czech GP at Masaryk – an 8.66mile road course which later became known as Brno. Lack of development meant the CZ team had to run an existing older bike in the race.
However, during 1969-70 further work saw the bike become competitive, although reliability was a problem. The team’s main rider, Bohumil Stasa, scored the 350’s first victory on May 5, 1970 at Horice, a public roads circuit in the factory’s home country – but the poor quality of Czech metallurgy seriously handicapped development of the engine. A new tubular frame was developed to use for the rest of the year.
In Grands Prix, the CZ was generally the best of the pack following Agostini on the MV. Stasa’s best GP result on the 350 was a second behind Jarno Saarinen in the Junior race at Brno in ’72.
In 1971 a 418cc version was built for the 500cc class with 28mm Dell’orto carburettors. The original 350 used an
eight-speed gearbox, but this was soon replaced by a six-speeder when the FIM introduced new technical rules limiting the number of gearbox ratios allowed. Some western components, such as Italian Ceriani forks and brakes, and Dunlop tyres, were first used at this time to improve chassis performance.
A total of 24 race wins in non-gp events were achieved during 1971-72, but probably the most impressive performance from the machine came in 1972 when it led Giacomo Agostini’s MV Agusta until it retired with mechanical problems.
For its final season in ’73, a front disc brake (replacing the 230mm fourleading-shoe drum) and a new Bosch ignition were fitted before the programme was cancelled after CZ was ordered by the government to concentrate on off-road competition. Rivals Jawa were permitted to maintain the Czech presence in road racing.
CZ’S design was basically sound. In final form, it produced around 73hp at 13,600rpm and had an estimated top speed of 260kph (161mph), but suffered from a lack of funds or advanced materials during its life. This led to the 420 weighing some 37kg more than the MV, while producing about 20hp less.
CZ enjoyed far greater success in offroad competition with lightweight, robust two-strokes, claiming seven world motocross titles (four in 250cc and three in 500cc), plus 15 International Six Day Trial victories with bikes supplied to the Czechoslovakian national team.