Colorado Kid

A new type of drive line might be more efficient then what you are using today. https://www.bicyeramic Drive Linescling.com/bikes-gear/a22092182/ceramicspeeds-driven-concept-might-become-the-worlds-most-efficient-drivetrain/

Gresp15C

"The system is still very much in prototype phase, and Smith said CeramicSpeed would likely partner with another company if it ever brings it to market. While the system met the design goal of reduced friction, other challenges and advantages of the system have not been fully explored, he said. "

https://www.bicycleretailer.com/prod...e-report-day-1

DanBraden

Wow, well your link was wonky AF, but I found the article. I would like to see it in motion for curiosities sake, but the article makes a good point about wether a 3% efficiency gain is worth dumping cash into (probably not for me, I'm cheap).

I might be showing my ignorance here, but I've never seen anything like this. In fact, outside of a motorcycle I've never seen a shaft driven bicycle. IN FACT, I saw a belt driven bike cycle in the wild for THE FIRST TIME last week and I've been cycling for +15 years!!!

I should get out more...

BobbyG

Very interesting! However my brain keeps saying "cheese grater". I would like to see it succeed.

RubeRad

Here you go:


This is a fascinating design -- it has the added bonus that the 'cassette' is completely flat, which will allow rear wheels to be built with more symmetric dish, thus stronger.

DanBraden

Thanks for posting the vid! I'd want a cable pull system, unless... Could the efficiency gains make a dynamo hub setup even more effortless? Maybe as long as the wheels are spinning you'd have power and not need to replace batteries? Ah, but then you're back to the old chain driven conical cassette once you start down that path...

Nope I'm back to the good ole cable pull non electronic shifting.

It'd be interesting to see how it handles shifting. I also wonder which setup can better resist shearing forces, the conical or the flat cassette?

These forums will be alot less fun if people can't get into arguments about which chain lube method is better than any other and why everyone else is wrong! Wrong! WRONG!

RubeRad

But hey, we'd get to have a whole new category of shaft-roller-lube flame wars

:

no motor?

Great idea! I'm sure there's some part of it to argue about here, and if there isn't one can be fabricated.

RubeRad

But should it be fabricated in carbon fiber? Or CNC-machined out of aircraft-grade titanium? Or lugged/silver-brazed steel?

YOU'RE WRONG!

DanBraden

I think I'm in the right place... Except I'm not paying $25 a year to embed no stinkin' video!

Argument Clinic

Keiffith

To me it's marketing wank. Not practical, and doesn't bring anything to the table other than "its new".

Refinement of IGH tech would be nice. But it doesn't cause any buzz so obviously it won't happen

DanBraden

This resonates with me

When I consider the pros and cons of internally geared mechanisms, I have this impression that it's a) heavier b) difficult to repair or modify and c) not as efficient or robust as an external hub (note I said "impression" I'm willing to be educated here).

The pros, on the other hand, is having a chain that doesn't shuttle around back there is appealing in it's simplicity. I'm sure there are others but for me it boils down to simplicity in maintenance and use.

RubeRad

maybe more difficult to repair, but because it's enclosed and sealed, also less likely to need repair.

79pmooney

Over a hundred years ago, Major Taylor set at least one world record on a shaft drive bikes. In the century since, chains have barely changed except to allow them to work better in off-design conditions (ie, poor chainlines). This suggests a well designed shaft drive should be quite viable. As I said in the previous thread on this drive train, this concept lends itself to being enclosed in a lightweight and areo enclosure(s), neatly getting around one of the big drawbacks to derailleur systems.

I have to wonder if there is a way to radial "adjust" the interface between the shaft bearing and the chainring or cassette to vary the gear ratio. Perhaps NuVinci (sp) has something that could be used, (They make the variable speed IGH. The mechanics are quite proprietary and I have never seen them.)

Ben

RubeRad

Look closely at that video, the 'rear shaft bearing' slides on a fixed rod so it can engage with a ring of teeth that are at various radii.

Keiffith

I've ridden both vintage Sturm 3 speeds and shim nexus 3 speeds. Simplicity and durability are more important to me then weight. But I don't like so few gears. Sure, a IGH right now isn't quite as efficient unless it's a rohloff, but they are $1,400.

I really wish rohloff would make a '75%' version. One that's just as efficient as a 500/14, but a tad heavier and less durable for $800-900. This would likely get them on oem's so we can squash the whole idea that derailers are the best we got for bicycles.

RubeRad

See also this new technology:

https://pinion.eu/en/p-line/technology/

But requires a special frame with a compatible bottom-bracket shell.

tyrion

I think that Ceramic Speed prototype has a major design flaw/constraint - the high gears are too far apart.

If the radius of those cassette teeth rings are say 1 cm increments, the diameter increments will be about 6cm (2 pi) - way too big a jump for the small "cogs".

Might be ok for a utility bike, but for racing and high performance - not gonna fly.

Darth Lefty 

RubeRad

Yeah, the flatness of the 'cassette' seems to imply it will lack the 3D rigidity gained by a pyramid structure. That's certainly something for their mechE's to consider.

Papa Tom

I think they'd stir up much more interest if they would post a video of it in action. Maybe I'm missing something, but in all the online articles I've read about this thing, I haven't seen one video yet.

Darth Lefty 

nasabiker

I don't think this particular one off idea will go anywhere but stuff like this is part of innovation and I'm glad people are thinking out of the box a little bit

I-Like-To-Bike

Maybe Elon Musk can make it, sell it for $10,000 per item, and lose $20,000 on each item sold.

bigbenaugust 

All of those pretty rollers won't be 99% efficient after a few days of road grime.