In the origins of Japanese motorcycling lies a pioneering brand often forgotten in the West: Aero-First (sometimes transcribed "Arrowfast"). Designed by Narazo Shimazu in 1925, this machine represents the transition from craftsmanship to mass production in the Japanese archipelago.
Considered by some to be the "father of the Japanese motorcycle", Shimazu was no mere mechanic. After building Japan's first gasoline engine in 1908, he devoted his efforts to aviation before returning to two-wheelers with a precise industrial vision.
His philosophy: to create a robust machine capable of withstanding the unpaved roads of 1920s Japan, while using Western-inspired production methods.
The Aero-First was distinguished by bold technical choices for its time:
- Engine type: Single-cylinder, 4-stroke.
- Displacement: 633 cc (some 630 cc variants).
- Valves : Side-valve architecture.
- Transmission: 3-speed gearbox (manual to tank).
- Top speed: Approx. 75-80 km/h.
- Major innovation: First integration of a reverse gear system on sidecars.
The Aero-First's most innovative feature was its gearbox. At a time when many motorcycles still used direct transmissions or rudimentary systems, Shimazu filed patents for a particularly robust, integrated three-speed gearbox.
The use of light alloys, derived from Shimazu's aeronautical experience, made it possible to lighten the crankcase without sacrificing strength.
In 1925, Aero-First marked a turning point with the creation of Japan Motors Manufacturing in Osaka. This was the first factory in Japan to use machine tools to standardize parts.
To prove the brand's reliability, a historic raid was organized:
- Route: Kagoshima to Tokyo (over 1,200 km).
- Result: a dazzling demonstration of reliability that boosted sales to around 200 units, a record for national production at the time.
Despite its qualities, Aero-First ceased production around 1927-1928. The massive arrival of American manufacturers (Harley-Davidson) benefiting from preferential tariffs, and the financial fragility of investors in the face of the economic crisis, precipitated this pioneer towards abandonment.
