Where can one purchase just a geared hub motor wheel, not a kit?

AxialFlux

Member
So, me and my infinite wisdom, put a 500w geared hub motor on my Townie for street use, and a 1000w direct drive hub motor on my mountain bike for trail use. I was hoping that the extra wattage would make up for the lack of torque in the DD motor, but alas, that is not to be. Went on a 7 mile test on some trails today, and the direct drive motor, while working great on the flats, really suffers on hills. I'd like to find a 29" 500w geared hub motor for this, but the only ones I am finding are shipping from China. I have a camping trip coming up the week of Oct 12th, and would love to have it in by then. I did get a quote from the company I bought the 1000w kit from, and they advised it would be cheaper just to get a new kit from a US shipper.

On another note, I need to check my programming (LCD3), as it seemed like I had more power using the throttle than using the PAS. I did check, and I do have the PAS Power (C14) set to 3, which I believe is the strongest setting.
 

JES2020

Active Member

AHicks

Well-Known Member
Yup, that's what I would do too. 750w Bafang is a good plan - unless you can find a MAC 10t or 12t. Those are 1000w+ and pretty much the ultimate. Went through this myself. Started with a 750w direct drive I found gutless, then to a 1500w direct drive, which was much better but still not what I was looking for. Then I went with the Mac 12t geared hub, which is just over the top (just right!). 35a KT controller has no trouble with it. Problem is now, the supply of MAC motors has dried up. Now it's all about the GMAC's - which are much more expensive, AND complicated.

As far as the controller issue, if you are pedaling when you hit the throttle, you are going to get everything available from the battery and controller - subject to the parameter settings (like C14).

If you stop pedaling prior to using the throttle, you'll find it MUCH more responsive to lower throttle settings and all the way up to max.

Does that answer your question?
 

AxialFlux

Member
Yes, I think so. I think the geared hub motor on the Townie is just a different animal. Using the PAS on it, I get the same speed/torque as if I am just using throttle, and the DD motor just doesn't feel this way.
 

JES2020

Active Member
Yup, that's what I would do too. 750w Bafang is a good plan - unless you can find a MAC 10t or 12t. Those are 1000w+ and pretty much the ultimate. Went through this myself. Started with a 750w direct drive I found gutless, then to a 1500w direct drive, which was much better but still not what I was looking for. Then I went with the Mac 12t geared hub, which is just over the top (just right!). 35a KT controller has no trouble with it. Problem is now, the supply of MAC motors has dried up. Now it's all about the GMAC's - which are much more expensive, AND complicated.

As far as the controller issue, if you are pedaling when you hit the throttle, you are going to get everything available from the battery and controller - subject to the parameter settings (like C14).

If you stop pedaling prior to using the throttle, you'll find it MUCH more responsive to lower throttle settings and all the way up to max.

Does that answer your question?
Hey Al, Does your 35 amp KT have 3 or nine pin motor connector? I have heard that anything above 30 a needs a 3 pin just wondering if you know anything about that.
 

AHicks

Well-Known Member

JES2020

Active Member
That's interesting. I just learned how to swap a 9 pin to direct connect of three big wires from that website. BUT what is being lost form the other wires not being connected? Also do you know what the difference is between sine wave and square wave?
 

Thomas Jaszewski

Well-Known Member
difference is between sine wave and square wave
Just a Google away,


SineWave FOC Vs Square Wave Controllers -- Which One Is Better?
09 Sep , 2020

- 0 Comment(S)
Which is better: Sinewave FOC vs Squarewave Controllers?
An analogy for the difference between squarewave (or Trapezoidal wave) and sinewave is like pushing a bowling ball down the street. Sinewave uses a smooth constant push the whole way, while squarewave attempts to simulate the same forces but uses constant jabbing/nudging instead of an even "push".
The loss of energy to sound (harmonic losses) in square wave controllers which is caused by the transitions between each of the 120 deg phase differences makes your regular cheap square wave controller less efficient.
Sinewave (or Field Oriented Control FOC) controllers are generally more expensive because it requires alot more computational power to output a sine waveform to drive the motor efficiently.
This image has an empty alt attribute; its file name is sinewave-squarewave.jpg




Square wave on the other hand is simple in its computation requiring just the 3 phase on/off signal to drive the motor in a time sequence. Here is how it works for a square waveform driven motor as it goes through its rev.

Here are the pros and cons of a sinewave vs square wave controller:
Sinewave FOC ControllerSquarewave Controller
Pros1. Lower noise and heat generated
2. Smoother fine speed control. Allows riders to maneuver turns without braking too hard
3. More efficient at lower speeds going up slopes
4. Smoother acceleration
1. Cheaper due to less computational power needed
2. No need to do motor tuning and matching
3. Produces more punch or torque during acceleration
4. Low motor efficiency at normal speeds due to noise and heat
Cons1. Higher price due to more sophisticated motor control
2. Inefficient at high speeds
3. Motors and controller needs to be paired and tuned
1. Noisier motor with more heat generated
2. Non-linear punchy acceleration
3. Voltage sag at high speed or acceleration may result in overheating or shutdown

So for workhorse controllers that require high efficiency for normal operations like cruising or slope climbing, sinewave FOC is the better option as they will not require such high power consumption.
On the top end, for high speed transactions, square wave controllers with its high torque and punchy drive will be more efficient but you have to accommodate for the high voltage drop by having a higher discharge and higher capacity battery.
So it seems there could be room for a best in class universal controller that will be able to be efficient at both low speeds and high speeds. At low speeds, it will output sinewave and at higher speeds it will configure to square wave. That would be the most ideal controller design but do not expect it to come cheap!
Here is an actual demonstration of 2 equivalent electric scooter setups. 60V 100A output with a 60V 21Ah battery. The only difference is that one is equipped with a sinewave FOC controller and the other with a square wave punchy controller.
This is only a drag race test to see which controller would come out on top over 30m. You would expect the square wave punchy controller to be much faster off the blocks every time which is the case but the FOC controller always catches up within a short distance due to its efficiency.
 

JES2020

Active Member
Mine is not one of the "waterproof" (Bafang) type controllers. The whole thing uses conventional connectors - which have been trouble free since installing. I used crimp on "bullet" connectors that I soldered on for the motor connections. I then slid heat shrink over the connections - without shrinking the tube, for easy maintenance. Similar to this one:

From the website posted:
"This controller is sensorless controller, so just have three big cable for motor wire If you motor have 8pcs wires or 9pcs wires, you just connect the three big cable,also the motor can be run"

(Are they leaving out that you must connect the other wires besides the 3 big cables)?
If you don't connect all the wires I would assume you lose PAS; ebrake; cruise and...
 

AHicks

Well-Known Member
No, I wasn't looking at that very close, or close enough actually. There are "sensored" and "non sensored" controllers in the KT lineup. One must be used with phase and hall sensors (8-9 wires), the other can get away with just using the 3 phase wires. The difference is the one using the hall and phase will start easier, meaning it will get you away from a light better, with less groaning.

Thomas' sine vs. square wave notes are pretty comprehensive (no surprise there)- but I didn't see them mention noise. Maybe I just missed it. Generally the square wave controller runs with a "ringing" noise, where the sine wave is silent. In practice, that's a big deal...
 

Thomas Jaszewski

Well-Known Member
but I didn't see them mention noise.
They did. And from personal experience a sinwave really does significantly quiet a motor. These days I’m using eBikes.ca controllers. I like that the controller can run on the most common batteries. 36v 48v and 52v. No need for any confusing programming.
 

JES2020

Active Member
No, I wasn't looking at that very close, or close enough actually. There are "sensored" and "non sensored" controllers in the KT lineup. One must be used with phase and hall sensors (8-9 wires), the other can get away with just using the 3 phase wires. The difference is the one using the hall and phase will start easier, meaning it will get you away from a light better, with less groaning.

Thomas' sine vs. square wave notes are pretty comprehensive (no surprise there)- but I didn't see them mention noise. Maybe I just missed it. Generally the square wave controller runs with a "ringing" noise, where the sine wave is silent. In practice, that's a big deal...
I see, so it those "extra" wires have nothing to do with PAS Etc?
BTW I ordered a 30 amp KT from China. I'll get it by the middle of Nov, just in time for the snow. I'll have the bike in the basement redoing the quick initial wiring and swap out the controller.

I expect next spring I will have a significant torque increase for my (supposedly) 1500w motor. Right now I think I'm getting 1188 w with a full 54.6 battery and 22a max kt. Vs 1638w w/ the 30 a kt. That's 450 more w of torque !
 

AHicks

Well-Known Member
They did. And from personal experience a sinwave really does significantly quiet a motor. These days I’m using eBikes.ca controllers. I like that the controller can run on the most common batteries. 36v 48v and 52v. No need for any confusing programming.

Difference in tastes. I LIKE the ability to fine tune/dial it in to my tastes. With KT you have the option. They generally run as you get them with the default parameters. Things like PAS sensitivity (how far the crank needs to turn before PAS is activated), adjustable low voltage cut out, max amperage available to the motor, etc. That's all stuff I like to play with. The big thing though, is what they call "imitatation torqe control" which is very well written internal software that limits power to the motor based on PAS level - leaving speed entirely out of the picture. Very similar to running a torque sensor.....
 

JES2020

Active Member
Difference in tastes. I LIKE the ability to fine tune/dial it in to my tastes. With KT you have the option. They generally run as you get them with the default parameters. Things like PAS sensitivity (how far the crank needs to turn before PAS is activated), adjustable low voltage cut out, max amperage available to the motor, etc. That's all stuff I like to play with. The big thing though, is what they call "imitatation torqe control" which is very well written internal software that limits power to the motor based on PAS level - leaving speed entirely out of the picture. Very similar to running a torque sensor.....
I know you can change the PAS level display indicator to affect the power available to the throttle instead of to the PAS. Does that give the throttle the option for more torque than if it's set to display PAS settings?
 

AHicks

Well-Known Member
I missed the part about using a CA3. I may go there someday. Like the day I get a GMAC...

Generally though, I think that display is past due to be upgraded. Not for what it's able to do, way more about appearance. No color available, large size, limited amount of info without changing pages... Newest Bafang and KT displays leave the CA3 wanting - my opinion.