On Thu, 20 Jun 2019 18:11:54 -0500, AMuzi wrote:

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.

The C.S. system supports the front and rear "pinion" with bearings.
The "ring gear" (to use your terminology) is supported at the "output
shaft" just like other 90 degree gear sets. See:
https://en.wikipedia.org/wiki/Bevel_gear

Re "ceramic" the term, while reminiscent of one's dinner plate, is
actually " Si3N4" a material that is 2 to three times harder than
conventional bearing steels, has a tensile strength of about 54,403
psi and a modulus of rupture of from 65,310 to 159,541 psi.
http://www.memsnet.org/material/siliconnitridesi3n4/

The question than becomes whether or not the "ring gear" will flex
when loaded and I suggest that the designers will have (probably)
taken that under consideration during the design phase. They have a
system in operation at present and undoubtedly will be testing for
that problem.
https://www.ceramicspeed.com/en/driven/

My own guess the real question will be that while the system
undoubtedly having less friction than a chain drive, whether that
reduced friction will be worth the money that the new system will cost
and will it be legal in bicycle racing.

At present the experimental system seems to be a 12 speed system and
whether that will be acceptable in these days of the 11 - 2 chain
drive systems with perhaps 20 effective gear ratios is, perhaps,
debatable, and lets face it, that is the key factor in developing a
"new" system. WILL IT SELL?
--
cheers,

John B.