here is a microfiche of the Valkyrie clutch----------the Rocket's can't be that much different.
After looking at this you can see a bit more of the workings and it may make more sense now.
There are multiple steel plates (keyed on the inside) in between the friction plates (keyed on the outside).
The parts keyed on the outside move whenever there are engine RPMs.
The parts keyed on the inside are keyed into the transmission.