Alan B
100 GW
Note that a DD brushless hubmotor is an alternator. You'll need the same size and weight to generate that amount of power. You definitely don't want to carry one around without using it as a motor as well.
Is REGEN, really worth it ?
- Thread starter rumme
- Start date
miro13car
100 kW
spiros said:
On my EPLUS ebike drive I have 9 power levels and 9 regen brake levels and it works wonderfully on incredible steep downhills returning free energy into my battery pack.
Free wheeling? I have power level 1 which consume around 10W
I can use whenever I want.
something for something
mid drive - free wheeling for the penelty of chain/sprockets wear ,
on my Eplus DD hub chain lasts for years and thousends of kilometers.
Chalo
100 TW
John and Cecil said:
Of course it would be technically possible to do that. Such a mechanism could even use a geared multiplier to increase motor speed on the regenerative cycle. But in practice, nobody does that. The most sophisticated regen systems I'm aware of use progressive regen as a sort of reverse throttle. They all drag the motor and its magnetic losses along for the ride at all times, though.
It seems to me a clutch mechanism that engaged automatically upon application of throttle or regen, but otherwise remained completely disengaged, would offer a very satisfactory bicycling experience. It could also slip during momentary overloads of the system due to shocks or suspension feedback.
I'd only consider using regen on a motor with proper torque anchoring, though. Applying constantly reversing torque through a flatted threaded axle is just dumb.
Alan B
100 GW
Proper torque anchoring is required, but it can easily be provided with flatted axles. Bicycle frames are not properly designed for that by default however, they are generally marginal for flatted larger axles.
John and Cecil
10 kW
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I do not know if it is worth it either, however people that ride in places like San Francisco, Italy etc and are constantly going up and down large grade hills might have a use for them. I'm killing my brakes going down steep hills and that is all lost energy to boot. I am accustomed to riding a motorcycle and with those the motor helps slow you down on the hills when you are off the throttle in the right gear, but the bike just goes with no resistance except for those tiny little disk brake pads that will heat up fast. I think if the regen hub motor could be light enough it would save the brakes. I don't mean save replacement costs (you can get a set of bike brakes for $3, I mean keep them cool and ready for action if needed. When I rode my motorcycle down steep inclines I would pump my rear brakes to keep the speed off and keep my front brakes fresh, and it had dual front rotors. The bike brakes are nothing like the motorcycle. I think regen braking could be a nice safety feature even if the energy created isn't that substantial. I am new to the bike and electric bike world though so I don't know much about them.
My situation is probably a little more unique too. My bike may be aluminum but between the bike, motor, a real battery, and the rear rack with dog carrier and 25lb dog I'm looking at 90 lbs of bike.
My situation is probably a little more unique too. My bike may be aluminum but between the bike, motor, a real battery, and the rear rack with dog carrier and 25lb dog I'm looking at 90 lbs of bike.
Chalo
100 TW
Alan B said:
The issue is that by using the axle stud to both fasten the wheel and transmit reaction torque, you've given it two jobs to do that work against each other. Transmitting torque through the axle stud tends to loosen the nuts that hold the wheel to the frame. The interrupted thread caused by flatting the axle dramatically reduces the thread's clamping ability and subjects the thread to damage and stripping at what would otherwise be normal fastener torques. And the same working clearances that make a bolted joint easy to fit up, make a flatted axle behave more like a pry bar than like a spline.
craneplaneguy
10 kW
I am really happy with my mid drive BBSHD, both of them, But yeah, when heading down a steep mountain slope regen sure would be nice. Mostly for the braking power. Has anyone considered one of these: https://www.amazon.com/s/?ie=UTF8&keywords=drag+chute&tag=googhydr-20&index=aps&hvadid=178101069494&hvpos=1o2&hvnetw=g&hvrand=15154458787076355731&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029427&hvtargid=kwd-287184388&ref=pd_sl_7bf24ro2zx_e
Sure it'd look goofy as hell, but one of them would be handy on some of the long downgrades I find myself on in my mountainous area. And no, I have no idea how you would keep it out of the rear wheel when slowing down.
Sure it'd look goofy as hell, but one of them would be handy on some of the long downgrades I find myself on in my mountainous area. And no, I have no idea how you would keep it out of the rear wheel when slowing down.
MadRhino
100 GW
craneplaneguy said:
Funny accessory, for those on ES who are bringing their bikes to acceleration tracks.
Down a hill, I wouldn’t want to handicap the advantage of gravity.
John and Cecil
10 kW
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- 529
I guess if you are not pedaling you can build webbing between your legs and the frame and then point your knees out to create a sail too.
I used to do this on one side (without the webbing!) when I was hit with powerful winds from the side on my motorcycles. If you point your knee into a wind gust it will help steer you back into the wind (like a sailboat tacking into the wind).
Actually the parachute idea is not that far fetched... But instead of a parachute it should be designed more like an umbrella and able to electronically open and close
I used to do this on one side (without the webbing!) when I was hit with powerful winds from the side on my motorcycles. If you point your knee into a wind gust it will help steer you back into the wind (like a sailboat tacking into the wind).
Actually the parachute idea is not that far fetched... But instead of a parachute it should be designed more like an umbrella and able to electronically open and close
DRMousseau
100 W
Let me start by stating that I really like Regen Braking,.... I liked it on other vehicles too, from golf cars to the kids Civic Hybrid. AND I like it on my e-bike as well. Being a heavy 29" beach cruiser, it coasts with pretty good momentum. I do have some anticipation ahead, but my heavy regen setting often lends a great assist to braking while relieving the brake pad wear ALOT.
NOW,.... I noted the momentum of coasting. If the DD hub drags much while coasting,... it's not greatly noticed by me. And with systems off and no battery mounted, I can only say it's jus a heavy bike to pedal across the lawn of the yard!.
But I gots a question,.... perhaps a result of my system, or settings, or normal? But regen seems only noticeably effective at speeds over 12mph. Between 10 and 12mph it seems barely perceptible, and jus non-existent under 10mph!!! Indicators show regen to be activated, but perhaps because of the heavy setup, it's jus seems not to be detectable below 10mph.
Soooo,... with wheel OFF the ground, I notice it jus doesn't "coast" and spin as freely as the front wheel. A quick "flick" spins it up to about 5mph, and it drags with light buzz that can be felt thru the frame momentarily till it rather quickly slows to stop. So IT DOES drag,... and contributes to "weightiness" of pedaling w/o power. But when spinning it up this way,... their is STILL no regen drag when activated! I spin it up under power to about 20 or so, and regen slows it very quickly, to jus under that 8-10mph, and then again becomes non-existant,... jus that "draggy" slow spin till it stops. This means all my sub-10mph slow speed stops are on brake pads exclusively, something I already knew, but wondered if this was typical, as it's much unlike the regen features of other EV's I'm familiar with, dragging to an eventual full stop. So is this normal and typical of most DD hubs???
I notice too, that "cruise" can't be set under 12mph!! And a low speed cruise would be kinda nice sometimes. But I gotta hit that 12min to set cruise, and that 12mph jus happens to be the lowest that regen is strongly effected with great notability! Over 12mph,.... and I find I'm physically bracing myself against the strong braking force of the regen alone as much as I would be grabbing a hand full of brake pad! Yes, I have it set high, and I like it like that. But is there any relationship to the settings of the controller regarding this cruise and regen oddity??? Is this maybe a minimum parameter of the controller itself?? Or is this typical and normal of most DD hubs?
NOW,.... I noted the momentum of coasting. If the DD hub drags much while coasting,... it's not greatly noticed by me. And with systems off and no battery mounted, I can only say it's jus a heavy bike to pedal across the lawn of the yard!.
But I gots a question,.... perhaps a result of my system, or settings, or normal? But regen seems only noticeably effective at speeds over 12mph. Between 10 and 12mph it seems barely perceptible, and jus non-existent under 10mph!!! Indicators show regen to be activated, but perhaps because of the heavy setup, it's jus seems not to be detectable below 10mph.
Soooo,... with wheel OFF the ground, I notice it jus doesn't "coast" and spin as freely as the front wheel. A quick "flick" spins it up to about 5mph, and it drags with light buzz that can be felt thru the frame momentarily till it rather quickly slows to stop. So IT DOES drag,... and contributes to "weightiness" of pedaling w/o power. But when spinning it up this way,... their is STILL no regen drag when activated! I spin it up under power to about 20 or so, and regen slows it very quickly, to jus under that 8-10mph, and then again becomes non-existant,... jus that "draggy" slow spin till it stops. This means all my sub-10mph slow speed stops are on brake pads exclusively, something I already knew, but wondered if this was typical, as it's much unlike the regen features of other EV's I'm familiar with, dragging to an eventual full stop. So is this normal and typical of most DD hubs???
I notice too, that "cruise" can't be set under 12mph!! And a low speed cruise would be kinda nice sometimes. But I gotta hit that 12min to set cruise, and that 12mph jus happens to be the lowest that regen is strongly effected with great notability! Over 12mph,.... and I find I'm physically bracing myself against the strong braking force of the regen alone as much as I would be grabbing a hand full of brake pad! Yes, I have it set high, and I like it like that. But is there any relationship to the settings of the controller regarding this cruise and regen oddity??? Is this maybe a minimum parameter of the controller itself?? Or is this typical and normal of most DD hubs?
If you disabled all the freewheels in the system, then you could get regen braking, but youd also have to ensure the chain couldnt derail when running backwards as it would during braking, and that the derailer itself wouldnt jam up from the opposite tensions it is designed for.John and Cecil said:
If you used a geared hub, then almost none of them will work for regen, because they have a freewheeling clutch built in so theyre easier to pedal without power. You could lock the clutch (weld, etc) or find one that has no clutch.
DD hubs are teh only ones that easily work with regen right off teh shelf--you just need a controler that can handle it, and a BMS (if you have one at all) that uses the same port for charge and discharge (if you want to ensure regen cant overcharge the battery--not really an issue if you arent going down a long hill with regen all the way *and* starting out at the top with a full charge).
Every persons situation is different, so it is worth it to some, and not to others. For me, the energy I get back isnt significant, but the extra braking most definitely is, as is the wear saved on pads--if I braked only with the pads, Id probably go thru a set every month, or maybe every couple of weeks, commuting in traffic on SB Cruiser and previously wiht CrazyBike2.John and Cecil said:
On my lightweight Fusin Test Bike, a relatively normal bicycle, regen wouldnt have made any signifcant difference to braking and not much to pad wear, if Id had it avaialble (was a geared hub).
On DayGlo Avenger, a more or less normal bike used for heavy cargo hauling, with racks/boxes/trailer, it was definitely worth it, when I used a DD motor on there.
Entirely depends on the controllers implementation of electric braking.DRMousseau said:
Its discussed in a number of places around the forum (search my posts for EABS and Regen to find the threads) but not only are there different levels and implementations of regen which may operate within different speed ranges, or behave differently at different speeds, there are also several different ways electric braking can be implemented, some of which get energy back, and some of which just waste the energy, and some of which actually use up extra energy to force even harder braking.
Again, thats controller dependent. Some are even programmable for regen type and levels, as well as cruise, etc. Some activate cruise with a button, some do it by holding throttle in one place for so many seconds, and some dont even have the function at all.
The mtoro itself has nothing to do with how the controller implements regen, though a motor that creates more torque under the same drive conditions that another does not, will also have more braking torque than the other motor, under the same braking conditions. Beyond that, its all up to the controller.
Alan B
100 GW
Chalo said:
One ebike frame I have has steel dropouts made to take a flatted axle (deeper), and with nordlock washers it never gets loose, no torque arms required. The problem with bike frames is incorrect dropout design for the flatted axles. Proper dropouts designed to take flatted axles just work fine.
Alan B
100 GW
Regen can only get you so far. With appropriate controllers a small amount of power can be used to provide excellent ebraking down essentially to a stop. It is just a matter of firmware in the controller.
John and Cecil
10 kW
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- 529
Thank you Amber, I don't think I want to disable freewheel though. Coasting down the very slight grades is terrific for efficiency. Perhaps if they make a generator that sits above the rear wheel and is lowered by a brake lever and uses a rubber coated roller of some sort to make contact with the wheel I will consider something like that. I am wearing out my rear tire super fast as it is, we def need to get a high mileage rear tire on there next time. I wish I could fit a moped type tire on my 650b rims
Alan B
100 GW
They do make generators for lights that contact the tire. I doubt you can take enough power out that way for braking.
Moped tires are great for commuters. They do add quite a bit of drag and are no fun to pedal without power.
Moped tires are great for commuters. They do add quite a bit of drag and are no fun to pedal without power.
John in CR
100 TW
rumme said:
"Best conditions" well over 20%. I've gotten 20%+ recovery on many rides, though I'd use regen even if there was no range extension benefit. I'd use it just to almost totally avoid brake maintenance.
wineboyrider
1 MW
John in CR said:
+1yep. My only mistake was using a high powered setup with front hub motor that forked up me forks and I wrecked ...LOL
I use my regen and only my brakes when I have to. I rode the bike awhile before I got it together and it is a much higher quality experience. Especially useful for long paved downhills that you don't necessarily want to ge faster than 30, I just ride the regen and it holds me there nicely. Useful for rolling up on stop signs/lights also. I use a mid drive on my mtb and don't feel the need for regen in the woods which is good because it would never work anyway.
The red button on the left is a momentary switch and located there I can also activate the front brake lever while holding it down.
Mid drivers always crow about how much better their systems are for climbing and I will give them that in off road situations but what goes up must come down and a good hub motor on a road type bike will get you up there no problem and the regen works great for the ride back down. If you know what you are doing with it. And believe me it isn't that hard to figure out!
The red button on the left is a momentary switch and located there I can also activate the front brake lever while holding it down.
Mid drivers always crow about how much better their systems are for climbing and I will give them that in off road situations but what goes up must come down and a good hub motor on a road type bike will get you up there no problem and the regen works great for the ride back down. If you know what you are doing with it. And believe me it isn't that hard to figure out!
Ianhill
1 MW
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- Sep 25, 2015
- Messages
- 2,871
From what I understand hub motor's can be up to 85% efficency +or- a few %, the efficency climbs with rpm, So when we use a perm magnet motor for an ebrake and regen the motor efficency at generating operates in reverse highest efficency of momentum turned back into energy is at high rpm and as the motors rpm slows down the efficency gets worse so dowm a steep hill fast pace blips of an ebrake is better than a long press down to slow rpm.
It's for this reason commercial busses with a lot of mass use hydraulic systems regardless of rpm upto 70% is regained and with a lot of kenetic energy that's a lot of energy stored in a hydraulic accumulator but it only makes sense on large vehicles dues to the added weight.
Hydraulics is also used on a kite system that regen's upto 500kw of power from using two kites on reels with an hydraulic motor pump and accumalator, Due to being on a trailer it's fairly static so it's weight has no issue and with increased efficency over electric these are then used with a purpose generator spun at its effIcent rpm the whole system is more effective than a wind turbine for its size with out the constant structure but they do operate at a much larger height so for air traffic could be an obstacle in the dark etc so it's design is currently being worked as we speak.
But back on topic it's better to have an ebrake and between 5 to say 20 % regen best circumstances than none at all if the extra cost is very little of the controller and a decent DD hub the saving in maintenence is worth it alone.
I only have a push button it's adjustable to a point in software by Bluetooth but it's not progressive but with it set to max on a 16inch moped rim it will break away on lose gravel but on tarmac it's super agressive and can be used alone with a front brake i adjust it down so its not killing the rpm to fast so i can pulse the ebrake and keep decent wheel rpm, the added disc is just piece of mind for myself really I need to swap my pads and tyres back to front to even the wear out as the rear pads are just like new and the front tyre fine but the rear tyre takes all the wear and front pads.
So really its best if you have some weight on you to get the hub pushed into the ground and some decent kenetic energy built up at speed to attempt to gather it back up in a efficent zone of rpm to get the best bang for buck.
It's for this reason commercial busses with a lot of mass use hydraulic systems regardless of rpm upto 70% is regained and with a lot of kenetic energy that's a lot of energy stored in a hydraulic accumulator but it only makes sense on large vehicles dues to the added weight.
Hydraulics is also used on a kite system that regen's upto 500kw of power from using two kites on reels with an hydraulic motor pump and accumalator, Due to being on a trailer it's fairly static so it's weight has no issue and with increased efficency over electric these are then used with a purpose generator spun at its effIcent rpm the whole system is more effective than a wind turbine for its size with out the constant structure but they do operate at a much larger height so for air traffic could be an obstacle in the dark etc so it's design is currently being worked as we speak.
But back on topic it's better to have an ebrake and between 5 to say 20 % regen best circumstances than none at all if the extra cost is very little of the controller and a decent DD hub the saving in maintenence is worth it alone.
I only have a push button it's adjustable to a point in software by Bluetooth but it's not progressive but with it set to max on a 16inch moped rim it will break away on lose gravel but on tarmac it's super agressive and can be used alone with a front brake i adjust it down so its not killing the rpm to fast so i can pulse the ebrake and keep decent wheel rpm, the added disc is just piece of mind for myself really I need to swap my pads and tyres back to front to even the wear out as the rear pads are just like new and the front tyre fine but the rear tyre takes all the wear and front pads.
So really its best if you have some weight on you to get the hub pushed into the ground and some decent kenetic energy built up at speed to attempt to gather it back up in a efficent zone of rpm to get the best bang for buck.
Dumsterdave
100 W
+1 for regen. I do a lot of stop and go and I can get 10% back from regen, but I don't really need the extra regen. I use it primarily to save on my brake pads. Before my current controller,I had a controller that didn't offer regen and I was burning through brake pads, but now I really only use my brakes when I'm barely moving to come to a complete stop.
miro13car
100 kW
DRMousseau said:
John in CR
100 TW
wineboyrider said:
For the highest % regen recovery I use low regen force. Then it's just a matter of getting used to the braking distances and speed to get to where you only use the mechanical brakes as the regen cuts out. I understand that some of the more advanced controller regen all the way down to zero, but I've never owned any of those...I'm too cheap and or they don't go to high enough current or voltage.
The smoothest electric braking I've had was with the Greentime 18fet, which doesn't charge the battery, but it does plug brake all the way down to 0rpm.
thanx to all those for steppin up to report your direct experience & not simply empty opinion.
unlike the big naysayer that can't allow a single regen related posting to pass by without his unsubstantiated commentary.
you saved me from citing all of the E•S builds that are leaving off rear mechanical brakes entirely in favour of regen only in the back.
this is fast becoming a growing trend as more & more clue in itz just that good.
here's the link one more time for all the good it'll do.
face it rocket-sturgeon, you've lost in your one man crusade to stamp out the heresy of regen.
if you or anyone has definitive numbers to refute justin's definitive testing i'm open minded & always willing to listen.
otherwise can someone in authority pls tell that girl to shut up.
unlike the big naysayer that can't allow a single regen related posting to pass by without his unsubstantiated commentary.
you saved me from citing all of the E•S builds that are leaving off rear mechanical brakes entirely in favour of regen only in the back.
this is fast becoming a growing trend as more & more clue in itz just that good.
here's the link one more time for all the good it'll do.
face it rocket-sturgeon, you've lost in your one man crusade to stamp out the heresy of regen.
if you or anyone has definitive numbers to refute justin's definitive testing i'm open minded & always willing to listen.
otherwise can someone in authority pls tell that girl to shut up.
