On Thursday, June 20, 2019 at 6:26:23 AM UTC-7, db wrote:
Check this: https://www.youtube.com/watch?v=-9gQ1KRhesM

It all looks beautifully smooth etc. But I wonder, how
does it stand up to hard pedalling, like standing on the
pedals on a steep uphill? Is the force transfer still smooth
and easy?

--
Dieter Britz

Deiter - that is an idea bike and nothing more. Drive shaft bikes are less efficient than chain drive. Ceramic bearings are totally unnecessary on a bike since the difference in drag between a steel and ceramic bearing is so small that it is undetectable except at auto-motor speeds. If I was building a world speed record streamliner the tiny difference could make a mark, but not otherwise.