Re-inventing the bike->drivetrain...

[oldpotatoe]

Doesn't look that complicated..does it?:eek:

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

[Gummee]

What was old is new again.

M

[monkeytusmc]

That does look complicated. It looks too expensive lol.


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[Spaghetti Legs]

Wow I didn’t realize drivetrain friction was what slows me down so much. Guess that’s why all that heat is wafting up from my chain at the end of a ride.

[jamesdak]

Wow, that chain ring will definitely chew you up if you get into it. OUCH!

[saab2000]

Anyone running this system? Is it compatible with mechanical disc brakes and/or tubular tires?

I haven’t found it yet on Wiggle or Ribble.

[sitzmark]

Long way to go to PoC - intermediate technology only at this point. Just sorting drive mechanics - gearing yet to go.

[Burnette]

Doesn't look that complicated..does it?:eek:

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

Thanks for the link. That's interesting ain't it? I guess it comes down to efficiency, wear and weight. Looks bonkers though!

[Veloo]

I'd like to see a CVT drivetrain so I can push a 53X15.5

[bigbill]

A whole lot of small bearings, the failure of any one will end the ride.

[Cornfed]

Fascinating stuff. Hope they continue the work if for no other reason than to explore the engineering challenge of shifting gears at speed, under load. Very cool.

[ergott]

A whole lot of small bearings, the failure of any one will end the ride.

Yeah, and small bearings are SO durable.

[bicycletricycle]

The way it stacks the gears concentrically is interesting from a packaging standpoint.

[stien]

I'd like to see a CVT drivetrain so I can push a 53X15.5


Uhh, look up Nuvinci 360.

[saab2000]

I applaud their efforts, but this isn't really new. There are internal gear hubs (Rohloff and Shimano are "mainstream" in this arena) and internal gear transmissions (Pinion) and shaft-drive bikes have been displayed before.

There's not much new here but given advances in material sciences and electronic shifting maybe they can make something of it.

I once read an article which cited data showing that as old as roller chains are they are very efficient and other drives are generally inherently less efficient.

I wish them luck. Always good to see someone thinking out of the box.

[CSTRider]

No more dropped chains ... but a broken driveshaft - YIKES:eek:

[charliedid]

Seems like a vanity project to me.

[joev]

Hmmmmmm....meat grinder.:banana:

[Hindmost]

Anyone running this system? Is it compatible with mechanical disc brakes and/or tubular tires?

I haven’t found it yet on Wiggle or Ribble.

You are going to need a new bottom bracket.

[smontanaro]

The way it stacks the gears concentrically is interesting from a packaging standpoint.

Back to 120 rear spacing! :banana:

I can envision how the shifter would be set up. The pinion gears ("gatling gun" I saw mentioned on iBoB) would slide along the shaft, which would be keyed to keep from rotating. The "derailleur" only has to push or pull the gatling gun in one plain, simplifying the mechanism.

Also, you might need a dork disc to cover the outward facing teeth, exposing them only at the interface with the shaft drive.

[saab2000]

You are going to need a new bottom bracket.

Deal breaker.

Btw, no way that can take the torque of a rider applying pressure vertically or laterally to the pedals.

[ptourkin]

Back to 120 rear spacing! :banana:

I can envision how the shifter would be set up. The pinion gears ("gatling gun" I saw mentioned on iBoB) would slide along the shaft, which would be keyed to keep from rotating. The "derailleur" only has to push or pull the gatling gun in one plain, simplifying the mechanism.

Also, you might need a dork disc to cover the outward facing teeth, exposing them only at the interface with the shaft drive.

It's 142. The GCN Eurobike Day 1 had a nice look at it.

Edit: NM - the Rotor was 142... people are poopooing that in another thread.

[benb]

Very cool concept, I am skeptical about them getting it done but great effort.

I'd want to see them try and do it mechanically too. That'd be amazing. If it's gotta be electronic I'm not sure I see it as a step forward.

There are some huge benefits if they could actually make it work.. that flat cassette would allow rear wheels to be a lot stronger if I understand correctly. Bye bye huge dish to accommodate ever more cogs.

[Mark McM]

You are going to need a new bottom bracket.

You're going to need far more than a new bottom bracket. You're going to need a whole new frame, and very likely special hubs and cranks as well (plus the new drivetrain components).

I'm skeptical that this drivetrain will ever see the light of day. Shaft drives have been used on bicycles in the past, and have so far not only been heavier and less efficient chain drives, but also had more drivetrain flex. Since there will only be one or two rollers in contact with the toothed plate, and because the roller wheel is relatively small in diameter, the forces on the "teeth" will be quite large, so they will have to be quite beefy and stiff. In addition, the toothed plate and the roller wheel will have to be held very rigidly together, so there will need to a fairly beefy fixture at each end of the drive shaft holding them together. I suspect that a large, thin plate for the multi-geared version won't be stiff enough either - if the plate flexes, the rollers may skip under hard load. They'd likely have to use buttresses to reinforce the plate. Another aspect is that since torsion is the least stiff flexing mode, the drive shaft will have relatively fat (and heavy) to have the same drivetrain stiffness. Not to mention the extra torsion loads on the rear triangle, which may require a reinforced frame.

If this thing were made, I'm sure it would end up being quite a bit heavier and more cumbersome than a chain drive derailleur system. I'm a little skeptical that the drivetrain losses can be kept below 1%, but even if it could, I think few would be willing to put up with a drive train that is several pounds heavier for increase in efficiency of only 1-3%