Nfixed ebike kits based in London

Bosa

Pedelecer
Jun 16, 2023
85
-4
 

guerney

Esteemed Pedelecer
Sep 7, 2021
11,240
3,192
What do they mean by "no need to charge"? It can't be serious...
Means they're free perpetual motion machines.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,560
3,053
Telford
Means they're free perpetual motion machines.
I have one of those. I put a motor in each wheel with only a tiny battery. I start pedalling and the front motor is wired as a generator to charge the battery. After a few meters, there's enough juice in the battery to work the rear motor that then propels the bike while the front motor re-charges the battery. It therefore has infinite range. It's brilliant.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,560
3,053
Telford
I am afraid cyclist might need to pedal more to charge battery, so it opposite to pedal assist.
Better still. bring your bike into your house, put it on a stand and pedal it to run your PC.

I've seen one guy put vanes across the spokes on his bike for a prolonged camping trip. When he stopped, he used it as a wind generator to re-charge the battery before carrying on his journey.
 
  • Like
Reactions: danielrlee

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,560
3,053
Telford
Regenerative braking might top up battery slightly. There is no way you can fully charge battery with that.
...unless I am missing something.
You can do the sums. Say you have a typical 400wh battery, and you can pedal along at a comfortable 100w. An ebike motor is about 70% efficient and you'd lose another 10% in rectifying and converting anything generated into battery charge, so you'd need 667wh put into the motor to charge the battery. That means that you would have to do the equivalent of pedalling for 6 hrs and 40 minutes to charge the battery.

The problem is that all of your 100w would be going to propel the bike, not charge the battery. To charge the battery, you'd have to pedal harder than normal- say 50w extra (150w total), which is what a fit cyclist does on an exercise ride. You'd have to do that for 13 hours and 20 minutes if you could. I would think that there's nobody on this forum that can do that unless they divided it up into 12 one hour sessions, in which case it would take nearly two weeks to charge the battery.

Regen always sound like a good idea, but when you try a bike with it, it sucks. Some people like electronically assisted braking, which steps up the regen to give a braking force, but the downside is always a bike that's difficult to ride without power, and you lose that bit we all enjoy - freewheeling down a hill.
 
  • Agree
  • Like
Reactions: flecc and Woosh

Az.

Esteemed Pedelecer
Apr 27, 2022
2,004
887
Plymouth
You can do the sums. Say you have a typical 400wh battery, and you can pedal along at a comfortable 100w. An ebike motor is about 70% efficient and you'd lose another 10% in rectifying and converting anything generated into battery charge, so you'd need 667wh put into the motor to charge the battery. That means that you would have to do the equivalent of pedalling for 6 hrs and 40 minutes to charge the battery.

The problem is that all of your 100w would be going to propel the bike, not charge the battery. To charge the battery, you'd have to pedal harder than normal- say 50w extra (150w total), which is what a fit cyclist does on an exercise ride. You'd have to do that for 13 hours and 20 minutes if you could. I would think that there's nobody on this forum that can do that unless they divided it up into 12 one hour sessions, in which case it would take nearly two weeks to charge the battery.

Regen always sound like a good idea, but when you try a bike with it, it sucks. Some people like electronically assisted braking, which steps up the regen to give a braking force, but the downside is always a bike that's difficult to ride without power, and you lose that bit we all enjoy - freewheeling down a hill.
In short it is much more effective to have road bike without "no need to charge" kit installed. As added bonus one can save 1k.

But there is a good chance we are missing something and they could get next Nobel price.
 
  • Like
Reactions: saneagle

danielrlee

Esteemed Pedelecer
May 27, 2012
1,391
719
Westbury, Wiltshire
torquetech.co.uk
I've seen one guy put vanes across the spokes on his bike for a prolonged camping trip. When he stopped, he used it as a wind generator to re-charge the battery before carrying on his journey.
You'd need a fair gust to make it worthwhile, but it's not a bad idea. Do you have any more information about this specific implementation (photo, link, etc.)?
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,560
3,053
Telford
You'd need a fair gust to make it worthwhile, but it's not a bad idea. Do you have any more information about this specific implementation (photo, link, etc.)?
No, it was about 8 years ago, probably on ES, though I do a lot of research into wind generators, so could have been anywhere. I searched, but couldn't find it. All I can remember was it was USA or Canada. Like you, I can't believe he got much out of it, but it was a very low cost installation, just the cost of some stuff to wrap around the spokes.
 

flecc

Member
Oct 25, 2006
53,128
30,555
Regenerative braking sounds good charge while you ride
No it doesn't sound good.

It's just a way of making cycling much harder than it needs to be.

That's why every attempt to introduce regeneration to electric assist bicycles over the years has been a failure.

A bicycle and rider hasn't remotely enough mass to make regeneration worthwhile. Even on today's latest fully electric cars the regeneration is barely worthwhile, the range improvement close to non existent. Its only value there being the motor braking, I know, I've been driving them for the last five years.
.
 
  • Agree
Reactions: Woosh

Az.

Esteemed Pedelecer
Apr 27, 2022
2,004
887
Plymouth
No it doesn't sound good.
Actually it sounds good. Just to good to be true.

I see why AI running investment fund might buy large quantities of those bikes. All what they need for it to work is perpetuum mobile patent.

On the other hand battery I have already has "no need to charge" mode. Other two modes are "in need of charging" and "charging mode" ;)
 
  • :D
Reactions: flecc

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,560
3,053
Telford
You can summarise all this:
Some of us have been watching e-bike development for very many years. Every so often there's a whole lot of publicity about some new ebike technology. We all get excited about it. We all discuss it for days, then someone eventually gets to try it after weeks of waiting, let-downs and correspondance, only to find that it's shite.

How many meaningful new products have come in the last 12 years and stood the test of time?

My list:
  • Bosch mid-drive, then others (There were Panasonic and others before, but not very powerful)
  • Bafang kit mid-drive
  • Tongsheng mid-drive with torque sensor
  • Downtube batteries
  • KT controllers
I'm not going to list them all, but how many bikes have been announced with fancy sytems - always a phone app - that you don't hear of anymore?

How many announcements have there been about new batteries with ground-breaking new technolgy have there been? I know how many we got - zero!
 
  • Agree
Reactions: robert44 and flecc