Could chainless drives have a viable future?

[Cycleops]

I never realised but they have been in development since 1975. Here's an interesting video which documents the latest developments:


View: https://youtu.be/r-Zyp6jX0HM

 

[Bollo]

Never say never, but I can’t see how this form of indirect drive could approach the efficiency of a chain (or belt). Maybe for an ebike setup where pedalling is only ever intended as a top up?

 

[ianrauk]

iirc there was a direct drive system doing the rounds a couple of years back. Think it was looking fir funding on kickstarter or suchlike.

 

[fossyant]

It's not as efficient as a chain or belt. Sometimes old is good.

 

[biggs682]

Belt drive yes but shaft no

 

[Baldy]

50% efficient?
Lags between peddling and moving?
Power surging?
The only production bike weighs 29kg?

Keep it simple stupid.

 

[Beebo]

If it was any good Dave Brailsford would have done it by now.
Marginal gains and all that.

 

[Big John]

I do try not to be a dinosaur and too set in my ways when it comes to cycling. I look out for new developments with interest and for sure there are some clever folks out there but I've not seen anything yet that would tempt me away from what I've got already, which is all conventional stuff i.e. no electrics. Conventional has its drawbacks but by and large if you look after your bike it'll look after you. Never say never, as they say, but so far I'm still waiting for the dream machine to arrive. I have seen a road bike fully kitted out with ceramic bearings though and that came close to the dream but at over £15k I decided against it 😂

 

[davidphilips]

Very interesting and contrary to most i believe there could be a market for such?

As with a lot of cycling products manufacturers design products that theres no need or reason for and market it as new and improved and as long as its expensive with a great profit margin it should sell well until another unnecessary product is marketed?

 

[Dogtrousers]

That's how diesel-electric locomotives work, so why not bikes? After all they are almost identical uses. OK, locomotives are slightly bigger - but not much.

 

[tyred]

A bike for Toyota Prius fans.

 

[Bollo]

Without going into too much of a deep dive, I had a bit of a hunt across that universal source of truth known as the internet.

A crude consensus says that reasonably maintained chain+derailleur-based drive will be about 90-98% efficient.

In contrast, a good ebike motor seems to be about 75% efficient, while you can get about 95% from a decent dynamo (this number is higher than I expected but I found it quoted in two separate sources). I’d be surprised if the power generated at the dynamo was transmitted directly to the motor. At the very least there’d be some small power loss from the associated electronics, but I’d also expect some significant drops for current/voltage mangling and regulation, so let’s allow a couple more % for that.

All in all that gives an efficiency on or below 70%, and I think I’m being generous. Thats an awful lot of extra effort doing not much apart from saving you some occasional chain cleaning.

 

[Jenkins]

Would that bike in the video be legal under the current legislation as it is pure electric drive and not pedal assisted and therefore classified as a motorbike/moped?

 

[Adam4868]

Saw this earlier.

View: https://twitter.com/TansuYegen/status/1593935347670568960?t=Ozy9gnbs5nJ7eDZgfBfuOA&s=19

 

[classic33]

Would that bike in the video be legal under the current legislation as it is pure electric drive and not pedal assisted and therefore classified as a motorbike/moped?

I wasn't the only one thinking that at least.