On 6/20/2019 5:52 PM, John B. wrote:
On Thu, 20 Jun 2019 13:26:21 -0000 (UTC), 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?

Well, one of the properties that make ceramic a better choice for
bearings is that it is harder than steel and the "teeth" on "pinion"
gears on the Ceramic speed machine are small ball bearings so I would
assume that they would withstand the rather weak forces of pedaling a
bike.

I believe that ceramic bearings are used in the engines of F1 cars
which produce hundreds of horsepower so a 1 hp (745 watts) cyclist
probably won't be a real problem :-)


It's not about ceramic or bearings. If you inspect worn
gearcases you'll notice the forces across a gear set want to
spread the shafts away from each other ( I think Frank
intimated that earlier). With the driveshaft inside a
chainstay I would expect failure to be from the big discey
thing flexing toward the spokes. Ceramic would shatter,
ceramic coated steel would need to be thicker. Just my
opinion of course but the term 'vaporware' comes to mind.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971