The Yamaha DT-1 made a huge impact on motorcycling in the US because it was truly dirt worthy. The 250cc, single cylinder, 2-stroke, DT-1 started a world-wide boom in trail bikes.
Packed full of technologies and features expressly for off-road riding, like a Ceriani type front fork with the longest stroke of any Japanese-made unit at the time, Autolube, a 5-port piston valve engine, wide-radius block-pattern tires and an engine guard, this model created the new genre known as "trail bikes."
As soon as it was put on sale in March 1968, the new off-road bike that could also be ridden on roads attracted attention as a completely new type of motorcycle, and its popularity exploded. Yamaha-sponsored trail riding courses, which were developed with the launch of the DT1, were also enormously effective. The model became such a major seller, moving at a rate of 500-600 units a month, that it practically created the market for trail bikes, which became a major category of motorcycles.
Yamaha based the DT1 on the YX26, a true motor-cross bike that had won the All-Japan Motor-cross Championship in May 1967. Until the YX26, the YDS1 and its 2-cylinder engine had been modified to be used in motor-cross, but the YX26 was a prototype that was secretly developed solely for motor-cross. Its technology was also utilised in the development of the DT1, which was to be mass-produced.
