Anyone had a play with one yet? Was curious about how they worked so looked at the video here:
I can see that when you pedal the angled splines on the freehub effectively screw the inner most sprung (spring pulling it away from the other ring) ratchet ring into the receiving one that is floating but keyed to the hub shell thus engaging the hub, but what provides the anti-rotation drag to make the sprung ring want to screw in along the coarse splines on the freehub?
Is it just the friction between the outer of this sprung ring and the inner bore of the floating one or/and something from the coil spring that is used in addition to the silent spring? Then when the teth start to engage the sprung ring is drawn in even tighter and forming a positive lock.
I see on the Shimano service documents they are quite strict on where grease should be. Quite worrying that a lot of the hub seems to have no lubrication.
While looking for the original patent as the images from it don't seem to show the coil spring I found an old (closed) singletrack discussion about this very thing https://singletrackworld.com/forum/topic/how-would-this-silent-dragless-shimano-freewheel-work/
Some posters seemed to be thinking that the sprung ratchet fully disengages from the splines on the freehub but I can't see that being the case, it must still be keyed to the freehub all the time or you would have to wait for that to engage and then the main set of smaller teeth.