Ceramicspeed DrivEn drivetrain

[Vetplant]

This fascinates me! Total out of the box approach! (then again, this was probably tried somewhere in the 60s already)

Can it work practically though?

https://www.instagram.com/p/Bk-SHKMgGI_/

https://cyclingtips.com/2018/07/ceramicspeed-driven-drivetrain/

[BaGearA]

this is an engineers wet dream

[Vetplant]

this is an engineers wet dream

Tell me about it!

 

I have long wondered why a driveshaft transmission isn't incorporated into cycling yet when it is the staple of the motor vehicle world.

 

Gonna be interesting to see whether they push this project along the development line with a big player or not.

[Capricorn]

This fascinates me! Total out of the box approach! (then again, this was probably tried somewhere in the 60s already)

 

Can it work practically though?

 

https://www.instagram.com/p/Bk-SHKMgGI_/

 

https://cyclingtips.com/2018/07/ceramicspeed-driven-drivetrain/

 

Variation on a theme: cars, trucks, motorbikes. all use this form of transmission. if it works there, it will work for bikes. Advantages though are another question.  CS mentions 99% efficiency? cool. tradeoffs? Limits of application? cost, longevity etc. all unfortunately are realities that need to be demonstrated. could be interesting for TT bikes. if you could hide the whole drivetrain inside the frame, could be a huge aero advantage.

 

Would be mint for that motor in the seattube..

[Schnavel]

this is an engineers wet dream

 

I know right - incredible!

 

But if people are complaining about the hazards of discs in crashes, just imagine what that "cassette" could do! Wouldn't like to be on the receiving end of that...

[Dieter ( ͡° ͜ʖ ͡°)]

This is the innovation we need! Not 6mm on an axle. I hope this makes it to market because I would love to this in real life. What a thing of beauty! 

[Grubscrew]

This will be prohibitively impractical to implement. It's effectively a bevel gear setup that uses a teeth/roller interface (like a chain) instead of the more usual teeth/teeth arrangement. As such the problem will be containing the induced radial force (r1 and x2 in diagram below) that pushes the gears away from each other. This is one of the main reasons why gears are usually built into strong cast metal cases. (To their credit, the teeth/roller interface does effectively negate the other main functions of a gearbox enclosure, namely keeping dirt out and keeping oil in.)

 

A human produces about as much torque as a small car at the crank, so that chain ring (ring gear) will simply flex/bend until the mesh is lost and it strips. The gear change mechanism at the back will suffer even worse. By the time they make it strong enough it will be way too heavy to be of any practical use.

 

[Grubscrew]

Here is an actual working shaft drive system, notice the amount of metal required around the gears to make it strong enough...

 

[BaGearA]

This will be prohibitively impractical to implement. It's effectively a bevel gear setup that uses a teeth/roller interface (like a chain) instead of the more usual teeth/teeth arrangement. As such the problem will be containing the induced radial force (r1 and x2 in diagram below) that pushes the gears away from each other. This is one of the main reasons why gears are usually built into strong cast metal cases. (To their credit, the teeth/roller interface does effectively negate the other main functions of a gearbox enclosure, namely keeping dirt out and keeping oil in.)

 

A human produces about as much torque as a small car at the crank, so that chain ring (ring gear) will simply flex/bend until the mesh is lost and it strips. The gear change mechanism at the back will suffer even worse. By the time they make it strong enough it will be way too heavy to be of any practical use.

 

small car ??

 

I would think even the smallest most crappy cars out there produce at least 40Kw , and I have yet to year of a sprinter that generate more than 3Kw for more than a few seconds

[Shebeen]

small car ??

 

I would think even the smallest most crappy cars out there produce at least 40Kw , and I have yet to year of a sprinter that generate more than 3Kw for more than a few seconds

not a petrol head, but even I know that power = KW, torque = nm

[V18]

Don't confuse torque and power.

[Showtime]

It's not a difficult calculation. A 1.3 Corolla engine can do 128Nm. At 90RPM cadence that is ~1200W which is doable for a sprinter.

 

Of course the car can sustain that torque at a few thousand RPM, not 90 hence the big difference in power.

[RaymondC]

Don't confuse torque and power.

Reminds me of the good old saying....  

 

Kw = How fast you get to the wall.

Nm = How far you go through it. 

 

[Capricorn]

It's not a difficult calculation. A 1.3 Corolla engine can do 128Nm. At 90RPM cadence that is ~1200W which is doable for a sprinter.

 

Of course the car can sustain that torque at a few thousand RPM, not 90 hence the big difference in power.

 

that's the key here: peak torque/power versus the average. For a strong cyclist, of say 85kg, assuming full mass pushed through 170mm cranks, that's already 85kg x g x 0.17m = 141.75N.m

That's excluding any muscular force produced, which should be a fraction of say 1RM squat. 

Point is, peak torque values produced by a cyclist look fantastic compared to say a small motorbike or car. However, it's not the more important and applicable average power value, which is far, far lower.

This is where ceramicspeed is pushing its business model: conserving as much as that average sustainable power as possible. 

however, this drive train of there's, unless it's mass is on par with current drive trains, it's just a look@us product.

[Eldron]

But. But. This was done 130 years ago :-)

[Grubscrew]

But. But. This was done 130 years ago :-)

 

And a multi speed version...