Manufactured 1983-1991
Jacques Coll, in his factory based at Saint Esteve, on the outskirts of Perpignan, built trials machines using modified Honda engines and later 250cc two-strokes of his own design. The Micra Trial 252 was presented at the 1987 Paris Salon with a 72 x 58.8 mm six-speed two-stroke engine. By 1991 it was offered with inverted front forks, giving buyers the option of conventional Marzocchi forks.
Thierry Girard rode the Micra in the 1990 and 1991 French Championship, and in the 1991 World Championship.
Alpha ceased production in 1991 due to increasing costs and low sales, shortly before the much anticipated water-cooled version was ready. Jacques took a position with Marc Tessier to design a new Bultaco in 1997. He died in 2006.
Between 15 and 20 Alpha 240, 210T and Micra 252 trials motorcycles were constructed.
Alpha 240 Micra 1989
Engine
Air-cooled 2-stroke single-cylinder. Bore x Stroke: 72 x 58.8 mm, 239.4 c.c. Power: 18.5 h.p. Torque: 2.5 kgf·m at 3800 rpm. Carburettor: Dellorto 26 mm. Six-speed gearbox. Cable-actuated clutch. Kickstarter
Chassis
Frame: Steel double cradle. Fork: Ideal 35 mm. Travel: 170 mm. Rear Suspension: Corte-Cosso monoshock. Travel: 170 mm. Brakes: front 185 mm disc. Rear 185 mm disc. Weight: 82 kg dry. Fuel capacity: 4 litres.
Alpha Micra 252 1990
Engine: 239cc (72 x 58.8mm) 2-stroke air-cooled. Power 20 h.p. @ 5000 rpm. Induction: carburettor. 6-speed gearbox, chain final drive.
Suspension: USD telescopic front, monoshock rear; Brakes: disc front & rear. Wheels: 21" front, 18" rear. Weight: 83 kg
Sources: François-Marie Dumas; Graham Clayton; retrotrials.com; Le Guide Vert, mangiapolvereoldirtbike.
N.B. Several firms use the name Alpha
