small direct drive hub motor ?
- Thread starter curious
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Anonymous
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Size does not matter 
, weight and efficiency does. I have x5 setup right now with big Kelly controller and a123 pack and it is a mini-motorcycle in terms of power. But not terribly efficient if you pedal along. I am thinking of a power setup for a recumbent right now with emphasis on range and efficiency. But I got completely hooked on regen braking so I'd like to get a DD hub. 9c is my first choice but I wanted to check if there is something even lighter out there.
, weight and efficiency does. I have x5 setup right now with big Kelly controller and a123 pack and it is a mini-motorcycle in terms of power. But not terribly efficient if you pedal along. I am thinking of a power setup for a recumbent right now with emphasis on range and efficiency. But I got completely hooked on regen braking so I'd like to get a DD hub. 9c is my first choice but I wanted to check if there is something even lighter out there.
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Anonymous
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dogman dan
1 PW
For the lightweight setups the gearmotors seem better. If you want the light weight to pedal easier without power, then the freewheel of the gearmotor is nice. If you pedal more, that more than makes up for slightly less efficiency when running. If you just want some assist at all times for really long rides, then all the medium size motors are pretty similar in performance and weight. I don't know of any that are smaller and lighter than a bafang or other gearmotor. For stealth though, motors that can be had in rear wheel dissapear into the bike better than front motors. A more silent dd motor is more stealthy than a gearmotor with it's gear whine. The best efficiency is had by simply riding slower. My atoema 700 watt direct drive hub will go 20 miles at 23 mph, but 40 is possible at 15 mph. As you ride slower, your pedaling becomes a larger percentage of the whole wattage, and the battery can go further when discharged slower.
In real world use, I find my fusin 350 watt gearmotor slightly more efficient than my 700 watt aotema direct drive. The lower wattage tends to result in slightly slower riding, which is much more efficient. Both motors can go the same speed, but somehow I feel less like riding fast on the gearmotor, and tend to do more coasting and pedaling while freewheeling. Mabye deep down I don't trust the little motor as much, and ride slower for psycological reasons? Whatever the reason, my killawatt meter tells me I use less power per mile on the gearmotor. I could ride the bigger motor more efficiently, but it just feels better to go fast on that one.
In real world use, I find my fusin 350 watt gearmotor slightly more efficient than my 700 watt aotema direct drive. The lower wattage tends to result in slightly slower riding, which is much more efficient. Both motors can go the same speed, but somehow I feel less like riding fast on the gearmotor, and tend to do more coasting and pedaling while freewheeling. Mabye deep down I don't trust the little motor as much, and ride slower for psycological reasons? Whatever the reason, my killawatt meter tells me I use less power per mile on the gearmotor. I could ride the bigger motor more efficiently, but it just feels better to go fast on that one.
adrian_sm
1 MW
curious said:
Wow. This is the first time I have heard someone sing the praises of regen on an ebike. I always thought it was a bit of a joke.
I have a 408, Xlyte controller, so only get back EMF regen. My normal commute doesn't have huge long downhill section, so I would generally prefer to not have the regen and go a bit faster. For the rest of the time I use normal braking. My CycleAnalyst says I get maybe 3% regen. Here is some stats from my typical ride to work.
I am interested to find out why you find regen so good. Is it better regen than mine, or a route that makes better use of it?
dogman - I have no need for stealth on the recumbent setup so for this project the size is irrelevant. My x5 bike is not very efficient even at low speeds - there is a lot of resistance in the hub (eddy currents and bearing seals). But I still want a DD hub just lighter and more efficient. BTW how does your aotema 700w stack against xlyte / 9C ?
adrian_sm - regen is a long and loaded subject. I am using a proportional regen controlled by analog sensor mounted on a brake lever. It may not extend the range by a lot but there are few definite advantages for hilly terrain:
- very strong braking with "boosted" action (at least with x5/kelly combo), it really feels very nice;
- no fading on long descents;
- psychological effect - I do not hesitate stopping or slowing down in front of minor obstacles instead of trying to maintain momentum;
- I found I can get better energy recovery if I keep pedaling downhill against the partially applied regen brake;
- I think I can further improve energy recovery on a lighter/slower setup (at the expense of braking power though).
adrian_sm - regen is a long and loaded subject. I am using a proportional regen controlled by analog sensor mounted on a brake lever. It may not extend the range by a lot but there are few definite advantages for hilly terrain:
- very strong braking with "boosted" action (at least with x5/kelly combo), it really feels very nice;
- no fading on long descents;
- psychological effect - I do not hesitate stopping or slowing down in front of minor obstacles instead of trying to maintain momentum;
- I found I can get better energy recovery if I keep pedaling downhill against the partially applied regen brake;
- I think I can further improve energy recovery on a lighter/slower setup (at the expense of braking power though).
Drunkskunk
100 GW
I haven't seen it available here, but 9c does make a lower wattage EU compliant hub motor that is smaller than the 500 watt ones we know and love.
I Imagine it should be lighter, too, but I'm guessing. I do know I've only see it personaly on a french site.
I Imagine it should be lighter, too, but I'm guessing. I do know I've only see it personaly on a french site.
BLUESTREAK
1 kW
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HI ALL. The 9C that JASON at E-BIKEKIT.COM sells has a sensor loop wire that when you plug the connetors together its cuts the power about half, On my wifes
MERIDIAN TRIKE running 48 volts it runs apox. 25 mph.with the loop unpluged and runs apox 16.5 mph with the loop pluged together, I just installed this 9c on this trike last week replacing the WE BL36-600 watt. IT starts smoother and performs much better. BUT there is no comparing the 9c on her trike to my "BLUESTREAK" MERIDIAN TRIKE running 48 volst on a front x5305.
MERIDIAN TRIKE running 48 volts it runs apox. 25 mph.with the loop unpluged and runs apox 16.5 mph with the loop pluged together, I just installed this 9c on this trike last week replacing the WE BL36-600 watt. IT starts smoother and performs much better. BUT there is no comparing the 9c on her trike to my "BLUESTREAK" MERIDIAN TRIKE running 48 volst on a front x5305.
Reid Welch
1 MW
Again, everybody is different in their wants and needs.
I, as all know, am using Justin's eZee: reasonably light weight, simple front mount version,
single speed basic, strong cruiser bike. It pedals manually just as fine on the flats as if it did not have a hub motor and battery at all.
Now, climbing even mild grades with pedal power only: not fun. I feel the extra weight of motor (ten pounds) and PING battery, (15lbs),
but, if I were twenty miles from home with a dead controller or motor or battery,
I could get back home, no real sweat. KISS for me. It's all I need here in Flat-or-i-da.
I, as all know, am using Justin's eZee: reasonably light weight, simple front mount version,
single speed basic, strong cruiser bike. It pedals manually just as fine on the flats as if it did not have a hub motor and battery at all.
Now, climbing even mild grades with pedal power only: not fun. I feel the extra weight of motor (ten pounds) and PING battery, (15lbs),
but, if I were twenty miles from home with a dead controller or motor or battery,
I could get back home, no real sweat. KISS for me. It's all I need here in Flat-or-i-da.
dogman dan
1 PW
The main points of the aotema are...
No halls. None, you can forget your regen controller if it uses halls.
Front hub only. No option whatsoever for rear install.
Otherwise, it seems comprable to clyte 408 or 407 in wattage and top speed. Not sure which 9 cont it compares to, but top speed is around 23 mph at 36v and 27 mph at 48v.
No halls. None, you can forget your regen controller if it uses halls.
Front hub only. No option whatsoever for rear install.
Otherwise, it seems comprable to clyte 408 or 407 in wattage and top speed. Not sure which 9 cont it compares to, but top speed is around 23 mph at 36v and 27 mph at 48v.
torker
100 kW
We need a way to measure cogging torque. My 9C does not seem to have much. I can spin the wheel and it goes a couple revs before stopping. But it does have some. I guess I could spin the wheel trying to maintain a certain speed and see how long it takes to stop. :?
Drunkskunk
100 GW
curious said:
That would be hard to call. There is so little resistance that its hard to tell.
My Clyte is a dual wound, and for certain the 4012 has more resistance, but the 408 and 9C 9X7 are barely noticeable. Its about like riding 10 pounds low on a 90 pound tire.
Honestly, One could roll half as easily as the other, But I can't tell by feel. The both roll too easily to notice when riding.
I had devised a way to measure cogging torque, sort of. The Coasting test.
Coast down a hill with the motor, and without. The % of time difference will be the % of energy being wasted by cogging forces.
It won't be much.
I've done the test, using my exgirlfriend on her unpowered bike coasting down a 1/4 road to the park. When I'm on an unpowered bike, we coast down and get to the bottom nearly side by side. when I coast down with the motor, i end up about a bike length behind her.
As close as it is, this is something that will need timing traps to check. a stopwatch wouldn't be accurate enough.
The results are also going to be an exponential curve, so it would need to be repeated on several grades of hill and then graphed to mean anything.
chet
100 W
On a bicycle, the only use for regeneration is for the braking assistance. At higher speeds or downhill runs it feels much safer than other brakes. Also, Golden Motor makes a mini hub but it is planetary geared.
alsmith
100 kW
nicko said:
I found this link for you about witches and electric bikes. :wink:
Looks like brooms are out.
The smallest direct-drive (DD) hub-motor right now is the Conhis. I can't imagine any conditions where it would be useful in a 26-inch wheel, even on fairly flat land. I have been curious about it as a possible mid-drive, since DD is quieter than a geared motor. Either way, here it is:
http://www.conhismotor.com/ProductsList.asp?id=113
http://www.conhismotor.com/ProductsList.asp?id=113
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