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Deze reply is gepost in de afdeling Main Forum in het onderwerp 'Nachttopic Deel 41 0:00 - 7:00' (ID 59258).
De reply is geschreven door gprnick (UserID 16174) op 25-11-2009 0:55.

Derbi

Although Derbi didn't compete with a work's team, they brought out a production racer for sale to the general public. This had an air cooled engine with a rotating inlet, dry clutch and six-speed gearbox. The cylinder was a simple aluminium one with hard-chromium plated bore, and a simple three port system. This cylinder should be the first to go if real power was to be developed. Also the crankshaft should go: with a bore and stroke of 38 x 43 mm was the engine no longer to be taken seriously! Claimed power was 15.5 bhp at 15,000 rpm, figures which seem with a view to cylinder and bore/stroke ratio somewhat optimistic - compare it to the data of the Kreidler tuning kit below. Torque 0.73 mkg at 14,500 rpm. Spanish IRZ carburettor with 24 mm diameter. Ignition by breakerless Motoplat thyristor system. Gear ratios: 2.1 - 1.666 - 1.411 - 1.222 - 1.095 - 1 : 1. The frame was open on the underside. Front forks and shock absorbers from Spanish Ideal, Aluminium Akront rims with Spanish aluminium brakes (double 2ls front, looks like a Fontani imitation). Wheelbase 1226 mm, claimed top speed 165 km/h.

http://www.elsberg-tuning.dk/1973.html