CeramicSpeed DrivEn drivetrain

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Duck!
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Re: CeramicSpeed DrivEn drivetrain

Postby Duck! » Mon Jul 16, 2018 9:32 pm

10speedsemiracer wrote:
bychosis wrote:I wonder how it copes with mud/rain/grit. The little bearings appear to be relatively unprotected.


I imagine the spin-rate would keep a lot of gunk out of there...maybe.

Curious conundrum... Although the shaft would be spinning at a decent rate, the little bearings would only go through a tiny movement on each moment of contact, so they'd have a very slow rotation rate, making them somewhat more prone to binding or suffering impact effects from dirt caught between the meat-grinder.... oh, sorry, sprocket teeth and the shaft lobe bearings.
I had a thought, but it got run over as it crossed my mind.

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Re: CeramicSpeed DrivEn drivetrain

Postby AUbicycles » Wed Jul 18, 2018 7:05 am

My concern is that the side force for the 'cassette' and driveshaft means that they are trying to push away from one another. While the shaft can be more rigid by connecting between the BB and dropout - the cassette unit in the lowest gears (towards the outer edge) are more likely to be affected by flex. Chain-slip would appear to be a bigger problem than with a more conventional drive.

An interesting observation is that there are fewer contact points. At the front and back, at any one point, there are only a few teeth while on a conventional chain around the front chainring, two jockey wheels and a cog, there is more contact.

I think this is very much where the efficiency claims come into play. Ceramic Speed eliminate the amount of contact points so on the condition that the drive is effective, there is certainly less resistance and better peformance. But I am speculating that the power transfer is the week point for the reasons mentioned above.

Drive shaft systems have traditionally suffered from inefficiency. Biomega has them and even the recent but failed IKEA bike though the drive shaft idea is over 100 years old. While it is nice to see a shifting concept on the Ceramic Speed (actually havn't seen it shifting) once any real power needs to go through, it is possibly that the performance gains are then lost because more friction is required between the driveshaft and from and rear cassette.

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Re: CeramicSpeed DrivEn drivetrain

Postby 10speedsemiracer » Wed Jul 18, 2018 7:26 am

I'd like to see it in a high-torque scenario, i.e. 90+kg rider, uphill, low-speed grind. Think the crown wheel at the rear would probably deform unless there's a very clever hub design behind it...I dunno, just speculating.
Mmm, SunTour

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Re: CeramicSpeed DrivEn drivetrain

Postby MichaelB » Wed Jul 18, 2018 8:51 am

10speedsemiracer wrote:I'd like to see it in a high-torque scenario, i.e. 90+kg rider, uphill, low-speed grind. Think the crown wheel at the rear would probably deform unless there's a very clever hub design behind it...I dunno, just speculating.


No need to speculate.

It WILL.

The ability for the 'cassette' to support any load and resist deflection that far from the centre support means it would have to be very stiff, therefore heavy, and therefore useless for what is proposed.

I re-iterate "dumb idea" all about marketing.

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Re: CeramicSpeed DrivEn drivetrain

Postby ironhanglider » Wed Jul 18, 2018 10:07 pm

I don't know why they didn't turn it around and have a single cog at the back and the 13 cog arrangement at the front with the teeth pointing inwards. That might help solve some of the issues raised above.

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Re: CeramicSpeed DrivEn drivetrain

Postby AUbicycles » Thu Jul 19, 2018 10:50 pm

ironhanglider wrote:I don't know why they didn't turn it around and have a single cog at the back and the 13 cog arrangement at the front with the teeth pointing inwards. That might help solve some of the issues raised above.


The 'deflection' problem isn't solved without removing the initial aim of low friction... and more importantly (but let me save my brain power), the sizing necessary to duplicate an expected gear range would likely still mean that the 'cog / chain ring' in the rear would be large and still have the 'stiffness issue.


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