O.S. Speed – B21 Adam Drake Edition 2



The O.S. Speed B21 Adam Drake Edition 2 has further brushed up the previous model born with advice from world-leading pro racer Adam Drake.

O.S. finished the engine that could win a big race that matched Adam Drake’s requirements. Bore x stroke of 16.4mmx16.55mm given only to this engine. Newly designed crankshaft for further improved driving feeling. Incorporating the latest engine factors, such as the inner head using an “O” ring with reduced vibration and dustproof performance, and the carburettor with a ball link that allows easy adjustment of the linkage used in B2103.


  • Designed with the advice and taste of ROAR champion title holder Adam Drake
  • A newly designed crankshaft
  • Inner head uses an O-ring with reduced vibration and dust resistance
  • Blue anodized φ6.5mm and Trugie φ7.0mm reducers are included as standard
  • O.S. Speed P3 gold plug with a reputation for medium and low speed torque performance is standard equipment
Stroke Volume3.49cc / 0.213 cu.in.
Bore16.4mm / 0.646 in.
Stroke16.55 mm / 0.652 in.
Output2.65 ps / 2.61 hp / 34,000 rpm
Practical Rotation Speed4,000-42,000 rpm
Weight353g / 12.45oz