GYTR Flywheel Question

[yz_for_me]

Yamaha lists its model GYT-5TA97-50-00 flywheel as being 1.4 kg-cm^2 inertia weight. How does this translate into the standard ounce designation all the other flywheel manufacturers seem to use? I'm guessing this is an 8 oz flywheel, but since kg-cm^2 is a unit of rotational inertia and oz is a unit of mass, there is no way to directly convert one to the other. I am assuming flywheels that use ounces to designate their inertia are actually oz-in^2. Does anyone kwow if this is correct?

[grayracer513]

There are two GYT-R flywheels that I know of. The lighter one is about a 5oz ring weight added to the original '03 YZ450F flywheel. This one came stock on the '04 as original equipment. The heavier one is about 8 oz added the the '03 flywheel, making it 3 up on the '04 model.

Compare these directly by weight only to weld-on types such as those from Dr.D, because the entire weight is added to the outside diameter of the flywheel. This makes the weight more effective in adding inertia to the rotating mass of the engine than bolt-on weights, ounce per ounce, since part of the weight of a bolt-on is given over to a center flange for bolting the unit on, and is so close to the center it doesn't do much.

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