Anyone ever tried to implement regenerative braking?

mr_ed

Pedelecer
Feb 15, 2022
116
18
Stripping of all you suggested.

The perfection of the invention of the bicycle was its simplicity combined with incredible efficiency and the reward of the pleasure that cycling gives.

Every power assisted bicycle loses that perfection and the more that it is refined in the manner you suggest, the more it becomes a motor vehicle, the more it loses the pleasure of truly cycling.
.
OK! What brings you to a power-assisted bicycle forum if you feel so strongly?
Unrefined power assisted bicycles are ok? But once they're refined they lose pleasure?

The whole point of those developments is to make the pedelec lighter, smoother, more reliable, more natural to ride, so hopefully closer to what you desire…
 
Last edited:

flecc

Member
Oct 25, 2006
52,945
30,448
OK! What brings you to a power-assisted bicycle forum if you feel so strongly?
I joined the trade in 1950 and was selling and fitting assist motors back then, so I have a very long experience and knowledge of them and their developments. It's an interest I've always retained.

Unrefined power assisted bicycles are ok? But once they're refined they lose pleasure?

The whole point of those developments is to make the pedelec lighter, smoother, more reliable, more natural to ride, so hopefully closer to what you desire…
No it isn't, the whole point of assisted cycling is to widen the numbers who can use bicycles as utility transport. That is precisely why their related law is as it is.

As a lifelong cyclist, almost all of it unassisted, I know what the pleasure of cycling is and equally know how power assistance spoils it. Pedelecs can have their own very real pleasure for many, but it isn't cycling pleasure and never will be.
.
 

Voltsnamps

Pedelecer
Aug 27, 2023
54
7
Hub motor but sounds like the perfect “clutch” . Motor, coast, regen
scroll to vid at end for good explanation.

 

Woosh

Trade Member
May 19, 2012
19,799
16,591
Southend on Sea
wooshbikes.co.uk
Hub motor but sounds like the perfect “clutch” . Motor, coast, regen
scroll to vid at end for good explanation.
Braking on a 100kgs bike + rider travelling at 25kph does not generate much power. The kinetic energy of 100kgs at 7m/s (25kph) = 2450J = 0.68WH. Some of it will be shed by the rotor, brake pads and the motor, the net recovered energy is even less if you only want to slow down instead of stopping.
the idea is good but I can't see it being adopted by major e-bike manufacturers.
 
  • Like
Reactions: flecc

Voltsnamps

Pedelecer
Aug 27, 2023
54
7
I totally agree, notwithstanding the difference between San Francisco and New York or mid Wales to Southend
i travel both scenarios, lotsamiles so watching carefully
my ideal would be tiny lightweight front wheel one, add minimal “pull” uphill to my BBS crank motor, full regen down
but this as is could convert me to a hubby hardtail, just to see if I could do it.
A good mate has leccy trials bike, not quite perpetual motion but pretty close, regens down (very slowly) pulls up like a train.
Steep is important for test.
Useless to the flat commuter, for sure
 

GLJoe

Esteemed Pedelecer
May 21, 2017
853
407
UK
All my discussions have been related to a well engineered solution, fully developed and tested by the manufacturer and with no additional parts so fully integrated within the existing motor/driveline (only exception being different brake levers with sensors).
Some high end manufacturers have successfully implemented regen on their bikes in the past (and may still be doing it).
Do some searching for (now old) threads with Stromer owners discussing this at length (not so much here on pedelecs UK - I'm thinking of endless sphere and possibly EBR) . Most of those models are direct drive hub, S-pedelecs and thus already have brake levers with switches which are then used to activate a well implemented and programmable regen if needed, as well as operating the rear brake light.

IIRC, as has been pointed out here, regen isn't very effective when used in certain (most) parts of the world where the terrain is mostly flat or gentle downhills, so then, its not worth bothering with, BUT ... in other areas where its particularly hilly (and one is braking a LOT of the time with steep downhill gradients), then its actually very worthwhile, both in energy recovery, but also saving in brake pads. Trouble is, this use case scenario is not typical for the majority of cycle routes. People living in the Alps or Pyrenees might beg to differ :)
 

AGS

Esteemed Pedelecer
Feb 12, 2023
563
174
My Sabvoton has regen, but I’m only using the ebrake functionality. And this is to provide braking assistance.

Sabvotons can be set up to provide fixed regen from the brake levers or lifting off the throttle or a separate throttle for variable regenerative braking.

Other controllers that can do this are Fardriver, Votol and Phaserunner to name just a few.

Even a KT controller has a regenerative braking feature, although this is very basic and I haven’t tried it because I’m using mine on a clutched geared motor.

You can’t set the regen current very high otherwise it will destroy the controller and damage the battery.

I have mine set at 30 phase amps to stop it overcharging the battery. And I think this provides upto 3 amps regen current into the battery.
 
Last edited:

mr_ed

Pedelecer
Feb 15, 2022
116
18
Hub motor but sounds like the perfect “clutch” . Motor, coast, regen
scroll to vid at end for good explanation.

What a great video and an exciting bit of innovation. Some really neat tricks there. I'd encourage anyone sceptical to watch it:


And to experiment with one of their common routes in the simulator to see if regen works for them:

It's over 10% on my routes; and sometimes much more. With a hub like this that needs no additional parts, what's not to like?
 

Voltsnamps

Pedelecer
Aug 27, 2023
54
7
There are those that say
Never mind the quality, feel the width !
Others of us see the long term, your planet may love you for it
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
5,207
2,509
Telford
What a great video and an exciting bit of innovation. Some really neat tricks there. I'd encourage anyone sceptical to watch it:


And to experiment with one of their common routes in the simulator to see if regen works for them:

It's over 10% on my routes; and sometimes much more. With a hub like this that needs no additional parts, what's not to like?
If you think it's so great, why don't you try it?
 
  • Agree
Reactions: Woosh

mr_ed

Pedelecer
Feb 15, 2022
116
18
If you think it's so great, why don't you try it?
....because it's a prototype and still under development? I recognise that people like Grin have the time, money, facilities, expertise to develop it more than I do.

When they're available off the shelf, then I might well buy one. Obviously you don't need to because you know all the answers already.
 

Peter.Bridge

Esteemed Pedelecer
Apr 19, 2023
864
390
What a great video and an exciting bit of innovation. Some really neat tricks there. I'd encourage anyone sceptical to watch it:


And to experiment with one of their common routes in the simulator to see if regen works for them:

It's over 10% on my routes; and sometimes much more. With a hub like this that needs no additional parts, what's not to like?
I watched some of that Video - seems a neat engineering solution. I very rarely use my brakes though coming down hill - just speed up and use the momentum for the next bit ! Wouldn't you need to put the hub motor on the front wheel though - that's where all the braking happens ? If so, there are some disadvantages. I'm sceptical to be honest - I would love to think you would actually get 10% regen in practical use, I think I'd rather stick with a rear wheel hub and get a 10% bigger battery if I needed the range.
 

mr_ed

Pedelecer
Feb 15, 2022
116
18
I watched some of that Video - seems a neat engineering solution. I very rarely use my brakes though coming down hill - just speed up and use the momentum for the next bit ! Wouldn't you need to put the hub motor on the front wheel though - that's where all the braking happens ? If so, there are some disadvantages. I'm sceptical to be honest - I would love to think you would actually get 10% regen in practical use, I think I'd rather stick with a rear wheel hub and get a 10% bigger battery if I needed the range.
You can put it on the rear… it’s on the rear in one of those videos. I know on a car most of the braking is done at the front but is that really the case on a bike? The weight/CoG is much higher on a bike… put it this way if I could chose which brake to fail on a steep hill I’d pick the front!

Interesting that the Honda patent for a motorbike has it on the front and rear linked.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
5,207
2,509
Telford
I watched some of that Video - seems a neat engineering solution. I very rarely use my brakes though coming down hill - just speed up and use the momentum for the next bit ! Wouldn't you need to put the hub motor on the front wheel though - that's where all the braking happens ? If so, there are some disadvantages. I'm sceptical to be honest - I would love to think you would actually get 10% regen in practical use, I think I'd rather stick with a rear wheel hub and get a 10% bigger battery if I needed the range.
Plus the effect of weight transfer to the front when going downhill.
 

mr_ed

Pedelecer
Feb 15, 2022
116
18
Yes, downhill massively, you can brake and lock up the back wheel and it won't slow you down that much
It’s interesting we do all these things subconsciously when squeezing the two levers. I’m assuming the regen firmware would also implement ABS which is incredibly effective.
 

Sturmey

Esteemed Pedelecer
Jan 26, 2018
586
326
67
Ireland
.......... I know on a car most of the braking is done at the front but is that really the case on a bike?
Its the deceleration that causes the major weight transfer from the back to the front during braking. But if you use your brakes to just control your steady speed going down a hill, there is no deceleration and hence no weight transfer (other than that caused by the tilt downwards/angle also cause change of center of gravity ) and most of the weight will still be on the rear wheel.

 
Last edited:

saneagle

Esteemed Pedelecer
Oct 10, 2010
5,207
2,509
Telford
Its the deceleration that causes the major weight transfer from the back to the front during braking. But if you use your brakes to just control your steady speed going down a hill, there is no deceleration and hence no weight transfer (other than that caused by the tilt downwards/angle also cause change of center of gravity ) and most of the weight will still be on the rear wheel.

The weight transfer from the tilt is substantial, which is why you do wheelies trying to pedal up steep hills, where the weight distribution becomes 0% and 100% on the two wheels. You can't get higher than that. The reverse happens going downhill, except the torque from the pedalling is replaced by the braking torque.
 
  • Like
Reactions: Peter.Bridge

Voltsnamps

Pedelecer
Aug 27, 2023
54
7
[I am also a front brake man
which is why I wrote this testerday but no one noticed

QUOTE="Voltsnamps, post: 715074, member: 43925"]

my ideal would be tiny lightweight front wheel one, add minimal “pull” uphill to my BBS crank motor, full regen down
Useless to the flat commuter, for sure
[/QUOTE]

I watched some of that Video - seems a neat engineering solution. I very rarely use my brakes though coming down hill - just speed up and use the momentum for the next bit !

You, if we take that at face value, could be the next downhill world champion, enter a club race or at least watch a televised race.
I can’t get around any of the hairpins on my local tourist route (sealed), let alone try to get down the mountain on tracks without braking. One gravel track I’m on the brakes enough for regen for 2 miles straight. A brave (or stupid) man would be doing 50mph all the way till he hit the steel gates at the end !
Hat’s off to you for sure, I’d love to watch video of your first attempt down Mt Blanc or even King’s Head Hill in Chingford E4 — my paper round when I was 12, Sunday papers on the front and back of my bike took some stopping with pissy rim brakes !
I could get back up (unloaded) without electric aid then, not a snowball’s chance in hell now.

Interesting that the Honda patent for a motorbike has it on the front and rear linked.
Honda only got a weird patent (pushing only some caliper pistons back and front), to get round Moto Guzzi’s existing patent.
My Guzzi I bought new in 1978 (and still my ICE transport) came with said linked brakes, I hated them and put it back to normal before leaving England on it in 1980. They would be horrible on a bicycle IMHO, just like ABS, some of us like stoppies and skids occasionally.