https://ebiketips.road.cc/content/news/schaefflers-chain-free-e-bike-system-now-in-production-4385

I bet it will fail, just as the similar Mando Footloose did:

 

I watched Spencer Kelly demoing the Mando Footlose in his BBC Click program a few years back. It was a disaster. Nice idea on paper but lacking a good battery.

https://www.bbc.co.uk/programmes/p02tw5w7

Gates, with their excellent belt drive has for a long time offered a "chainless" solution, void of at least of the issue Spencer Kelly found in the Footloose interpretation.

"Smart" electronics though could address that lack of synchronisation but I question whether the underlying concept of alternator based drives will be bugged by relative inefficiency issues?

I can see it not requiring mechanical gearing so recoup in that area, but at the same time be hampered again by the coupling with a hub drive with their speed to efficiency characteristic.

Does open up freedom of overall bike layout design by shaking off the mechanical link though, and facilitate "styling", often in itself a selling point.

If you have a cadence sensor on your e-bike, you can just remove the chain any time.

What's the likely efficiency of pedal power capture in 'normal' usage?

I'd guess (and it really would be a guess) around 80% pedal input power to electric output power, another 10% loss going into then out of the battery, and finally 80% at best electrical->mechanical power in the motor.

 

If the battery was flat the circuitry could connect pedal power to motor directly and at least you could keep going; but that would be somewhere around 60% efficient at best?

 

It should be easy to fix the other issue of an absurdly sensitive kickin as you pedal.

What's the likely efficiency of pedal power capture in 'normal' usage?

I'd guess (and it really would be a guess) around 80% pedal input power to electric output power, another 10% loss going into then out of the battery, and finally 80% at best electrical->mechanical power in the motor.

the design is a bit daft. Pedalling power reduces required motor assistance and battery consumption. The design adds the weight of the dynamo, cost and conversion loss.

the design is a bit daft. Pedalling power reduces required motor assistance and battery consumption. The design adds the weight of the dynamo, cost and conversion loss.

 

Doomed to fail. There's the huge efficiency loss compared to chain and sprocket at high 90s percentage efficiency.

 

But worse still when setting off is the feel of pedalling hard and fast before equivalent drive reaction happens, frustrating to say the least.

 

A bit like the way CVT was implemented in some small cars. Foot down, engine revving like mad but the speed increase only very gradually following.

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On the upside, it removes the single point of failure we sometimes hear too much about. (even if it adds a few more)

On the upside, it removes the single point of failure we sometimes hear too much about. (even if it adds a few more)

 

But given there's up to 40% efficiency loss, the far more sensible, efficient and clean way to deal with that is to have shaft drive.

 

Especially with electric assist power. The lack of shaft drive with a suitable gear system is the gaping hole in current pedelec design choice.

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On the upside, it removes the single point of failure we sometimes hear too much about. (even if it adds a few more)

 

What's this particular "single point failure" issue anyway?

Chainless bikes is how the whole cycling thing started Link "A", and is still going strong LINK,

It's not a complete "failure", other than one of ingenuity.

Interesting.....I think anything that makes a bike more 'user friendly' is good and might attract people back to cycling that would otherwise be put off by things like dirty chains falling off etc. It might especially work well in this case as the users may only make short journeys or have weak legs or just wants to ghost pedal anyhow.

I suppose I am also thinking back to the early computer days when computers were command/language /basic inputs. The simplification by using graphic user interfaces for the user. despite its inefficiencies, transformed the computer into something more 'user friendly'. (eg Apples Lisa in 1983) and changed everything.

Anyhow, just a thought.

Kirstin uses a Sussex shaft drive on his commute e-bike and has done so now for several years , as he said an enclosed drive that doesn't suffer from chain rust or the attacks of the salty sea air he is exposed to. An ideal clean drive set up.

Edited March 21, 20233 yr by Nealh

Driven Technology's new geared shaft drivetrain looks interesting:

 

 

https://www.youtube.com/watch?v=eimLIkJaNFM:402

Edited March 21, 20233 yr by guerney

What's this particular "single point failure" issue anyway?

Chainless bikes is how the whole cycling thing started Link "A", and is still going strong LINK,

It's not a complete "failure", other than one of ingenuity.

I apologize to anyone who took my 'single point of failure' comment seriously.

Drivetrain technology will only change for the masses when Shimano and SRAM get involved. Shimano have bought the CUES system which still uses the chain and cassette system. I thought Shimano would have made their Alfine hub thru axle compatible and brought out a belt drive system. Sram are making refinements to their current set ups