O.S.S.A. Wildfire 250 Racer
With Phil Aynsley
While better known for its off road bikes O.S.S.A. (Orpheo Sincronic Sociedad Anónima) achieved its first competition success at the 1967 Barcelona 24 Hour race where a tuned version of its 230 cc Wildfire street bike won outright and was followed by a standard model in third place (a Triumph 500 was in second)!
OSSA was founded in Catalonian Spain in 1924 by Manuel Giró (who was partnered with Francisco Bultó – who went on to found Bultaco – racing sidecars) and made cinema projectors.
In fact the company’s emblem that is commonly thought to be a four-leaf clover is actually a stylised escapement mechanism from a projector.
After WW II the company began manufacturing motorcycles with the first production bikes on the market in 1949.
They went on to compete in the 250 World Championship with rider Santiago Herrero, winning 4 GPs before his death at the IOM in 1970. OSSA withdrew from road racing at that point.
However that is getting ahead of the Wildfire story. It begins in 1954 when OSSA employed Italian Sandro Colombo (ex-Gilera) to design a 2-stroke motor for the company.
Originally a 175 cc it went on to be the basis for most of their motorcycle models, in 230 cc and 250 cc guises, until factory production petered out around 1984.
The 1967 230 cc Wildfire street bike made 25 hp at 7000 rpm and weighed a tad over 100 kg. A four-speed gearbox was used.
While the motor was a basic piston-port 2-stroke one interesting feature was the 32 mm IRZ double needle carburettor.
This provided separate jetting and needle for low-mid throttle and a second set for full throttle operation via a divided slide with two cut-aways. The bike’s handling was reportedly excellent.
The bike seen here was constructed from a road bike by WA racer Dennis Craine in the early ‘70s and won the WA state titles in 1971 and 1972 following factory supplied tuning information transforming its performance.
It was campaigned in both 250 and 350 cc sizes with the 350 being good for 35 hp.
| OSSA Wildfire SS 250 | |
| Engine | Air-cooled single-cylinder, 230 cc |
| Bore x stroke | 70 x 60 mm |
| Power | 25 bhp @ 6500 rpm |
| Induction | IRZ 32 mm carb |
| Ignition | Electronic flywheel magneto |
| Gearbox | Four-speed |
| Final Drive | Chain |
| Frame | Tubular steel double cradle |
| Suspension | Telescopic fork, swinging arm, dual shocks |
| Tyres | 3.00 x 18 front, 3.00 x 18 inch rear |
| Brakes | Drum brakes |
| Wheelbase | 1310 mm |
| Seat height | 787 mm |
| Weight | 95 kg |
