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Husqvarna 500cc Twin “Baja Invader” – 1969

If one cylinder is good, then two must be better! Or so thought Husqvarna engineer Ruben Helmen in 1966 when he designed production 250cc motocross components into a horizontal twin-cylinder engine. Without any major funds from his employer, he designed crankcases that could easily be cast by Husqvarna for mainstream production.

The motocross testing was handed over in 1968 to R&D rider, Rolf Tibblin and subsequently to 4-time World 250cc Motocross Champion Torsten Hallman. Hallman first raced the Twin on spiked snow tires before concluding that this was definitely no motocrosser. The engine was too wide, even though it was extremely fast. Unfortunately, the 500 Twin never made it to production and only one motocross/offroad version was ever built.

Baja Invader wins Baja 1000
In 1969, the 500 Twin was raced in the 5 European F.I.M. Cup motocross by Husqvarna rider, Gunnar Nilsson. The series, primarily to retain interest in the 501cc to 750cc sector that featured outmoded British 4-stroke iron, was easily dominated by Nilsson and the powerful Husky Twin. Fresh from this success, the bike was shipped to U.S. importer, Edison Dye. Edison’s vision was for this powerful machine to race the Baja 1000, one of the most grueling races on the earth. Riders, Gunnar Nilsson and J.N. Roberts were selected to pilot the machine. With speeds around 110mph, the 500 Twin won the 1969 event by 20 minutes. It was raced in several other events in 1970 and 1971 and then laid to rest in Dye’s warehouse for over 20 years.

Massive Motor
From the side, it’s very difficult to see the difference between the Twin and other early Husqvarna’s. Oh, but from the front or top, one is overwhelmed by the size, especially the width of the engine. This ex-Baja 1000 winner is the only Husky twin dirt bike ever built. It remained in Edison Dye’s former Husqvarna warehouse until 1998 when Dutch enthusiast, Frans Munsters purchased the bike and restored it meticulously to original specification. It now resides at Tom White’s Early Years of Motocross Museum.

Specifications
Engine: Piston port, 2-stroke twin, 490cc(69.5 x 64.5mm), 4-speed transmission
Power rating: 60hp @ 6500 rpm
Fuel System: 2 Amal Concentric 1 1/8”
Suspension: Husky telescopic forks-35mm, swingarm rear with Girling Shocks
Wheels/Brakes: 21” front w/drum brake, 18” rear w/drum brake – Akront rims
Weight: 265 lbs-dry

In reality, only 10 engines were ever built, with two going to road racer Bo Grannath, seven to European sidecar racing, and the Baja Invader.

Images are property of The Early Years of Motocross Museum, ®2006