To generate a hub moment, each blade needs to be freely hinged. Doesn't the Tie-bar in essence force the blades to respond in unision because they're not actually freely hinged! I read at the bottom of the page (http://www.synchrolite.com/1127.html) that the Tie-bar could be elastic, which might help a little.

An interesting two-bladed helicopter was the Sud-Ouest Djinn. It had a rigid hub and 2-offset hinged blades. That was a small helicopter with a gyro-bar for addedd damping.

Vilayti,

Thanks for the reply.  

The blades should not have to be hinged to create a hub moment. Theoretically, an absolutely rigid rotor could create a hub moment. Yes, the Tie-bar does force the blades to flap (teeter) in unison, like the blades on a teetering rotor. I believe (hope) that the force vectors that are parallel to the mast and are located at the end of the offset arms, will apply a moment to the hub, just like a fully articulated rotor.

If this is incorrect, please advise.