Expanding chainrings born again

That's like the Yankee Bicycle from thirty years ago, which was I'm sure an adaptation of something much older. The fact that it was brought to market thirty years ago (you could buy one at the mall at the Nordic Track store) but it failed then, and wasn't tried again for a few more decades, should tell you all you need to know about it.

These were made for many years and used for commuting successfully, but bike racers did not like them so they stop making them. Another perfect example of how the Racing industry has turned bicycles into a disposable aluminum junk yard.

All three of these were made differently.

                                         The new one:

http://www.vitalmtb.com/videos/member/Cool-Tech-VYROs-Multi-Segment-Gear-System,14722/bturman,109

Not sure about this one:

And one made by Browning:

http://www.bikeforums.net/classic-vintage/924521-browning-automatic-no-not-gun.html

The old ones made of steel were too heavy for modern man, weak form driving cars!! 

http://www.zoxed.eu/photos/bikes_drives.html

Geared Mid-drives / Zero Trail Steering / Variable Speed Crank / Tilting trike technology 

/ how to motorize a big vehicle/ Hub Motors /

http://www.oldbike.eu/museum/hello-world/oldbike_online_bike_museum-2/