[MattR]

Question:
What is the difference between the XC/DE flywheel and EC flywheel?
Does the XC/DE flywheel with a 10oz or 14oz weight equal the EC flywheel?

Answers:
The effect of the flywheel is more than just mass. It is dependent upon the radius about which this mass rotates. This property is called the "moment of inertia" or MOI. This property applies to all rotating objects like wheels, brake rotors, and all rotating engine components (crankshaft, pistons, rods, clutch basket, etc.), not just the flywheel.

Assuming only the effect of the flywheel MOI (no other engine components), the following can help explain some differences between the XC/DE and EC flywheels.

Compared to the MOI for EC flywheel:
MOI for XC/DE flywheel is approx. 30% of EC flywheel.
MOI for XC/DE flywheel (with 10 oz weight) is approx. 46% of EC flywheel.
MOI for XC/DE flywheel (with 14 oz weight) is approx. 63% of EC flywheel.

Therefore, the XC/DE flywheel will have a much different effect on the power distribution compared to the EC flywheel. The power distribution for the XC/DE flywheel will be snappier like a MX bike. By adding a flywheel weight (10 oz. or 14 oz.), the engine will build its power slower than before. However, only the EC flywheel have the greatest effect on power characteristics. Note: the bike will still produce the same about of horsepower... just the manner in which the power builds is different.