O.S. Speed R2105 Combo Set

The O.S. SPEED R21 series won the previous World Championships held in the United States.
With the new 'R2105' series, most of the parts have been designed from new to aim for consecutive victories at the world championship to be held in Japan this year.

To increase torque on high-grip track surfaces, a newly designed 9-port sleeve has been adopted. O.S. SPEED's traditional DLC coated crankshaft delivers linear power from low to top end by changing the counter balance. The outer head has been mirror finished and uses a clear coat from the conventional colour to a silver head base. By adopting a thrust plate made out of steel, wear due to interference between the connecting rod and the cover plate during rotation has been reduced and engine life is improved.

Adopting the latest design to most parts of the engine, it has been designed to the flagship of the O.S. SPEED on-road engine range.

• To increase torque, the sleeve adopts a newly designed 9 ports.
• By redesigning of the crankshaft’s counter weight, power delivery from low to high end has improved.
• A polished finish has been applied to the silver head.
• A new casting was adopted for the crankcase, and the O.S. SPEED logo was incorporated into the exterior design.
• Based on the 21M, which already had a great reputation, the needle O-rings have been changed from 1 piece to 2 pieces to prevent the needle adjustment from changing.
• By adopting a thrust plate made out of steel, wear due to friction between the connecting rod and the cover plate during rotation is reduced and engine durability is improved.

Supplied as a combo with R2105, header and pipe. Also available as the R2105 engine only.

Specifications
Weight	345.0g / 12.17 oz.
Displacement	3.49 cc / 0.213cu.in.
Bore	16.08mm / 0.633 in.
Stroke	17.20mm / 0.677 in.
Power Output	2.80 ps / 2.76 hp / 35,000 r.p.m.
Practical RPM	4,000-45,000 r.p.m.