GEAR INPUT 50CC FOR CFD Computational Fluid Dynamics Based Optimisation of High Speed and High Development of a Numerical Approach for the CFD Simulation of a Gear Development of a Numerical Approach for the CFD Simulation of a Gear. TRANSMISSION SECONDARY SHAFT WITH GEAR ECMU0100 Cobra CX50 KING 2016 TRANSMISSION SECONDARY SHAFT WITH GEAR. Cobra Moto Parts offers all dirt bike parts for 2016 Cobra CX50 KING. We carry all Cobra Bottom End Transmission Parts including Bearings, Seals, Crankshaft and more. We ship all Cobra parts nationwide at Guaranteed low pricing.