What do the "Guru's" say?

[markz]

I have been looking for the vids and info of Justin and other "Guru's" talking about a wide range of, everything motors.

Basically a few things bug me. The main.... Many people whine about trying to stay legal so they dont get thrown in the Gulag by "The Man".

Another is trying to wrap my brain around the aspect of KV, winding and torque.

I did it to help me out, but hopefully help others out too. Just spent a couple hours or more combing over it.

Justin
https://endless-sphere.com/forums/viewtopic.php?f=2&t=14482&p=218275&hilit=myth#p218275

The 6x10 winding won't really have any more torque than the 7x9 or 9x7 windings. You'll only get marginally more torque off the line and at a stall because the controller and phase lead losses will be somewhat less, but the effect is going to be pretty small, and can be negated with the faster winds by using heavy 10 or 12 AWG phase wire between your controller and the motor. As soon as you reach any appreciable speeds, then the slow 6x10 winding would have LESS torque than the faster windings for a given controller/battery combo.

Justin
https://endless-sphere.com/forums/viewtopic.php?f=2&t=24593&p=381600&hilit=myth#p381600

Hey Ken, as with all cases of the same motor option with just a different winding, if you are going up a hill where both motors are running the controller at the current limit, then you will get a marginal amount more torque from the slower motor due to 2nd order effect. This is exacerbated a bit by the fact that the HT3525 has a slightly higher copper fill factor than the HS3540 (63 strands vs. 60 strands). However, if the hill is not steep enough to cause the controller in the low speed motor to run at its current limit, then the higher speed motor will do the climb faster hands down.

If the myth continues that the slower speed motor winding leads to a higher torque motor, then ARRG I will want to roll in a grave. Crystalyte is not doing the scene a favour by using a High Speed / High Torque naming convention. It should be HS/LS for high speed, low speed. Since speed is already implied by the last two digits (40 and 25 kph respectively), then it's redundant anyways and H3540 and H3525 would be better.

Justin
https://endless-sphere.com/forums/viewtopic.php?f=2&t=7891&p=980986&hilit=myth#p980986

You'll notice that (ableit after some lobbying) Crystalyte is no longer referring to the motors as HT3525 and HS3540, but just H3525 and H3540? The original scheme with HT supposedly meaning "High Torque" and HS supposedly meaning "High Speed" was only propagating this same misinformation that the different windings result in different motor torque capabilities, and that there is a tradeoff between speed and torque. The H3540 and H3525 motors are wound differently, yes, and they are both fundamentally capable of exactly the same speeds and torques, it's just that the 3540 winding does it at a lower voltage and higher current than the 3525.

Justin
https://endless-sphere.com/forums/viewtopic.php?f=2&t=64907&p=984783&hilit=myth#p984783

John answered this pretty well but there are a few additional points I'd like to make. One is that the Crystalyte motors do NOT necessarily all have the same copper fill, and usually the very fast wind motors end up with a lower stuffing because of the physical challenge to deal with hand winding a huge parallel strand count. So I'm pretty sure that the H3548 is this way, much like how the Crysatlyte 5303 had a lower copper fill than the 5304 because they used the same stranding but just did 3 turns instead of 4 turns. This is where the "X x Y" designation, confusing as it is, at least has some benefit that you can see the actual total copper strands. So the Nine Continent 7x9 windings clearly has a bit more copper than the 10x6, (63 strands vs. 60) so you'd expect somewhat better torque all else, but the 9x7 was identical.

When you compare two motors that do have the same fill, like the slower 7x9 with the faster 9x7, you still get a difference in the torque output off the line, because the faster winding motor needs more current to produce the same torque, and outside the motor, more current means more losses in the motor controller and motor phase leads (but not the battery leads, as the battery current stays the same).

Here for instance is a comparison with the slow wind H3525 and the fast wind H3540, using a controller with 50 mOhm combined mosfet + lead resistance. Clearly the actual torque output at low speeds is about 10% higher on the slow motor:

Simulator Comparison, 50mohm.jpg
Simulator Comparison, 50mohm.jpg (103.43 KiB) Viewed 1230 times



Now replace the controller on the Faster 3540 winding with one that has fatter gauge wire so that it's only 10mOhm of resistance, and you can see that the torque difference between the two systems almost completely vanishes

Simulator Comparison, 10mohm.jpg
Simulator Comparison, 10mohm.jpg (110.13 KiB) Viewed 1230 times



Hopefully that gives some clarity on why you do both in practice and on the simulator see more torque with the slower motors. It's not that the fast motors produce less torque, but as a system with the same controller and phase wiring gauge then no doubt the motor that draws fewer amps will have less losses outside the motor, and that means more total power flows into the hub.

To me, an apples to apples comparison means that when you select a low turn motor, you are running at a lower voltage and higher current in general, so your phase wire gauge, controller mosfet resistance etc. should scale down accordingly so that the external losses are the same. In that apples to apples sense, motor winding really makes no difference as the graph above shows. The blame for lower torque with the fast motor does not lay in the motor, but in the controller and external wiring.

Justin in a youtube video, by Electric Bike Review Youtube blogger/reviewer.
https://www.youtube.com/watch?v=IxB2j-egWcQ
@ 6:00 and @ 7:50
@11:30 legal and @12:00 power @12:15 cont. amp and rpm.
@18:00 Battery cycles, SOC (Dont charge fully, but to 80% or 90% battery length increases)
@21:00 BMS phantom draw
@27:00 Bosch charger 3 pin, just need 5V to hack and 5.3A charge max.
@29:00 Ah consumed, rather then remaining.
@30:00 skateboards
@43:10 - The old store location, CA,

Video on water ingress
https://www.youtube.com/watch?v=gwlbAJLzI_w

This is more for me, but hopefully will help others out.

I will reserve a few spots for other "Guru" quotes.

 

[markz]

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[markz]

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[dogman dan]

This stuff gets crazy complicated, and I'll never fully understand the way motor winding, voltage, load, and efficiency interacts. I just can't handle the math.

But I am, and will remain the kook here that likes a low rpm hub motor for certain specific conditions.

Those conditions start with you don't want to go fast ever. If you want both fast and low speeds from hub motors, then you will have to choose a motor rpm and rim size that allows that speed without going to awkwardly high voltages. I used to say, just volt up the low rpm motor. I don't anymore.

The other conditions are stuck with a big wheel, like 26" or larger, for reasons stupid or smart or economic, AND the load is way too much. A guy weighing over 300 pounds, or a trailer, AND, you cannot use a large amount of power. Stuck with 1000w or less,, for reasons like you can't afford a good enough battery, or you wish to be actually legal, or whatever.

Lastly long steep hills. Like over 5% grade,, and miles long.

So too heavy, too big a wheel, and too low power. If you are stuck with this, a lower rpm dd hub motor will go farther up those hills than a higher rpm dd or geared motor before the smoke comes out. All will be suffering, but the lower rpm motor will climb it slower, suffer less, and have a better chance of getting to the top.

ITS NOT MORE TORQUE. It's just running slower, and more efficiently under those impossible conditions than the fast wind.

The better solution, is to wise up and lower the gear of the hub motor,, that is,, make the wheel smaller than 26". That works best of all.

 

[spinningmagnets]

There are so many unspoken givens at the start of any conversation about whats "best" around here. New readers may not realize that, as experienced builders are already known for certain preferences. Like don't recommend disc brakes to Chalo, or high volts with multiple stages on small motors to LFP.

I've driven a nail into a wooden board once with a large wrench, but...if I had a hammer, it would have worked better. Plus, if you are going to fix some roof shingles once a week (like riding an ebike once a week), go out of your way to get a hammer. By that I mean, your budget, your user profile, and specific job you want to use the ebike for all influence what is "best"

 

[d8veh]

I don't get why people say that faster wind motors give the same torque as slower wind ones. I can see that it would be similar torque if you changed the voltage in proportion, but say you have a 48v battery and 20 amp controller, then the low speed motor will always make significantly more torque at low speed compared with the high speed one. You can see it on the simulator. Look at the 250 rpm and 350 rpm Ezee simulations. From start the 250 rpm one makes 20% more torque reducing to about 10% difference in the mid-range. If they made the same torque, then they would have the same efficiency and there would be no point in having the low speed one.

I guess that there's a misunderstanding of what's meant when somebody says they give the same torque. "Capability to make the same torque if given the right batteries and controllers", yes. "Make the same torque with the same battery and controller", no.

 

[MrDude_1]

Whats the question here?

 

[spinningmagnets]

If I understand LFP correctly, one of the main issues in low-kV / high turn-count motors is the wire is thin.

If presented with a choice of two non-hub systems where they both have the same top-speed (due to sprocket sizes adjusted for that), he'd rather promote high-amps / low-volts...compared to...high volts / low amps.

Of course without any restrictions on the design, I suspect he likes non-hubs due to the ability of the drive sprockets being adjustable so he can use high-amps AND high volts.

 

[nutnspecial]

This is proper question frame?
https://www.youtube.com/watch?v=jofNR_WkoCE :lol:

*Disclaimer: I am not guru . . . or fox

Very nice OP Markz. Excellent work!

 

[dogman dan]

250 and 350 rpm ezees have that big a difference in copper fill?

 

[MadRhino]

2 motors of the same brand and model, can have differences in coil weight. They can also have many other small differences in how tight and varnished they are, even how true they are spinning on their axle. When they are of different winding turn count, the chances of those differences happening are increasing.

My experience with abusing and frying various hub motors, is that a slow winding will deliver more torque per Amps, but a fast winding will be able to pull so much more Amps that it is capable of more torque. Of course this is at the cost of feeding it that extra current efficiently.

 

[chas58]

I don't get why people say that faster wind motors give the same torque as slower wind ones. I can see that it would be similar torque if you changed the voltage in proportion, but say you have a 48v battery and 20 amp controller, then the low speed motor will always make significantly more torque at low speed compared with the high speed one. You can see it on the simulator. Look at the 250 rpm and 350 rpm Ezee simulations. From start the 250 rpm one makes 20% more torque reducing to about 10% difference in the mid-range. If they made the same torque, then they would have the same efficiency and there would be no point in having the low speed one.

I guess that there's a misunderstanding of what's meant when somebody says they give the same torque. "Capability to make the same torque if given the right batteries and controllers", yes. "Make the same torque with the same battery and controller", no.

Good point. I'm probably guilty of that

I think people are upset that low speed motors are called high torque by some vendors**. That is misleading. Yeah, below 5mph they are going to pull noticeably harder. But, that difference quickly gets to be less than 10%. Personally – I wouldn’t call that “high torque.” And no, it is also not the same torque. I would say the torque is similar once the bike is rolling.

Here is an overlay from the simulator:

**most people here that have been around long enough, know that low speed motors are chosen to keep the motor in a better efficiency range at lower speed, and minimize heat loss and damage at lower speeds. They are usually not chosen for the extra torque. People new to the ebike discussion don’t intuitively know this.

 

[chas58]

I'll just add, that having built the same bike with both a "high torque (200rpm)" and a "high speed (328rpm)" motor, I can hardly tell the difference in torque. Yep, there is maybe a 10% difference, but not enough to sneeze in my experience. The torque is "almost" the same.

 

[markz]

Its all sinking in now. I was hesitant to view my thread, thinking I'd get bashed in some way.

But that graph you linked too above.
You take a high speed motor and you install thicker gauge wire then the torque curve is the same. Lower resistance. But as John in CR posted, in the thread I linked too, he basically said, he would rather have more torque in the higher speed range on the high KV motor, because the low KV motor nose dives at a certain speed. I think its like 20mph or something. That makes sense to me. But I also look at TeslaNV's measurements on the amps a motor can take, and I look at the low and high kv and see a huge difference. This sells me on the fact I want a high kv motor. However the draw back is, if you can call it a draw back, is the high kv motor needs more amps.

I was saving the other 2 spots for more quotes from other "guru's" on this subject. Its more for my benefit, but I thought it would help others out too.

 

[Dauntless]

I was hesitant to view my thread, thinking I'd get bashed in some way.

Oh, you just haven't voiced an OPINION yet. Get going on that and the floodgates will open.

 

[MikeSSS]

I'll throw some babble in here. Torque is twist force. Power is what moves the bike or other vehicle at some given speed. Power needed for a given speed, is the sum of power needed for rolling resistance and power needed for air resistance and power needed for climbing.

Power can be thought of in more than one way. The units for power are foot*pound per second, ft*lb/s, aka ft lb/s, aka ftlb/s.

One way of thinking of power is: power in ftlb/s = torque in ftlb, times rotational speed in radians/second. Radians per second has the units of 1/sec. So, power in ftlb/s = torque in ftlb x rotational speed in 1/s. 1/s is said in words as, per second.

This sounds more complicated than it actually is.

Example: a turning bike wheel that has 20 ftlb of torque, where the rubber meets the road, and is turning at 120 rpm. Stop, wait, we can't use rpm, first convert 120 rpm to 2 rps, revolutions per second. Next convert 2 rps to radians per second. There are 2*Pi radians in one revolution, that is 2*3.1416 radians per revolution. 2 rps = 2*(2*3.1416) = 12.57 radians per second, aka 12.57 1/s. Now we can calculate the power of the bike wheel ... 20 ftlb * 12.57 1/s = 251 ftlb/s. Hmmm, thinking of power in Horse Power units is more familiar, there are 550 ftlb/s in 1 HP. 251 ftlb/s / 550 ftlb/s per HP = 0.46 HP. We can also convert this power to watts, there are 746 watts per 1 HP. 0.46 HP = 341 watts. That's a lot of watts, at the gym I can produce 80 watts for extended time and 220 watts for short sprints. My ebike ride average around 120 to 160 watts from the battery and also some watts from my pedaling.

A second way of thinking of power is this. Consider a bike being towed and there is a spring scale in the tow rope. The tow rope has 10 pounds of tension force in it. F = 10 lb. Power = tow rope force times bike speed. Tow rope force is in lb, bike speed is in ft/sec. A quick but not totally accurate conversion from mph, (mi/hr) to ft/s, is to divide mph by 2 and multiply by 3. So, 10 mph = 15 ft/s. Like I said, this conversion is not really accurate but it is close enough for calculations done in the head. Also, to convert ft/s to mph, divide ft/s by 3 and multiply by 2.

A bike being towed with 10 lb of tow force, and with a road speed of 10 mph, has a road speed of 15 ft/s. 10 lb * 15 ft/s = 150 ftlb/s of power. 150 ftlb/s of power = 0.27 HP. 0.27 HP = 203 watts. This bike has a lot of combined air and tire drag, that's for sure.

The third way of looking at power, concerns power put into the bike and rider during climbing, and released from the bike + rider during descending. Power = combined weight in lb, times vertical speed in ft/s. Note vertical speed, not road speed. To get vertical speed we need road speed and % gradient of the road. Example: a 180 lb rider on a 60 lb bike, has a combined weight of 240 lb. Let's suppose the rider and bike are climbing at 0.3 ft/s vertical speed. Power = weight * vertical speed. Power = 240 lb * 0.3 ft/s = 72 ftlb/s. 72 ftlb/s is 0.13 HP. 0.13 HP is = 97.7 watts. Also note, the climbing power is = the time rate of increase of the gravitational potential energy of the rider and bike, GPE/Time.

When the rider and bike descends, the GPE put into the bike and rider is released and converted into speed, actually it is converted into kinetic energy, KE.

Total power required = tire drag power + air drag power + climbing power. On level ground, climbing power = 0. During descent, the rider and bike are partially or completely powered by the decrease of their GPE.

Motors and turns of wire.

When a voltage is applied across a motor, current flows through the motor and the motor rotates. When the motor spins, it not only acts as a motor but it also acts as a generator. The spinning motor generates a voltage that opposes the voltage applied by the controller. Hmmm.

Under load, the motor will spin at an rpm, such that the back voltage that is generated by the motor, is less than the forward voltage supplied by the controller, and so the motor will spin. With no load, the motor rpm will increase until the back voltage generated by the motor, is equal to the voltage applied by the controller. At that point, the rpm of balanced voltages, back V = forward V, will be the motor's maximum unloaded rpm. So, many motors that are run wide open, without load, will reach and be stable at their maximum, unloaded rpm, and no damage will occur. Warning, some motor designs have limited back voltage generation capability. Running this design motor wide open my cause an overspeed condition, such that the motor destroys itself.

High turn motors, like a 12 T, generate a given back V at lower rpm, than do low turn motors, like a 6 T. So, high turn motors operate at lower rpm than low turn motors.

Low turn motors have less length of wire, and larger diameter wire, than high turn motors and therefore less internal resistance than high turn motors. Because the low turn motors have less internal resistance to current flow and also lower back V, at a given speed, than high turn motors ... the low turn motors can develop more power than high turn motors, they may even generate more torque. But, the low turn motors will have their power and torque at higher rpm than high turn motors. High turn motors will have more torque and power at very low speeds than low turn motors. Low turn motors will have more power and torque at medium to high rpm, compared to high turn motors. Besides that, low turn motors will have higher maximum power and maybe even higher maximum torque than high turn motors.

So? Well, if you like to ride at low speeds and/or need good climbing ability, then high turn motors are the choice. If you want to ride at normal speeds and can provide all the pedal assist needed for your climbs, then low turn motors are your choice.

What about geared hub motors? Well, the gears are little and not made of hard steel, so they are better suited to high rpm, low torque use. Huh? Yep, a 12 T motor will be harder on the gears than a 6 T motor. On the other hand, Ozzz posted a thread about his Continental Divide, 2,700 mile, ride. IIRC, he used a 12 T, MAC, geared hub motor and it did the ride for him.

Hope this nonsense is of some use to somebody.

MS

A second

 

[d8veh]

The theory is not that complicated, but it's often difficult to understand it, because people often don't make it clear what' parameters are variable and what's fixed when they compare characteristics. Here's a simple explanation:

If you're talking about a normal 1000w DD motor with a 48v battery and a 25 amp controller in a bike with 26" wheels, the low-speed wind motor will climb steeper hills and climb more efficiently, and the high-speed wind one will go faster and produce more power at high speed to maintain that high speed. The low-speed motor will accelerate more quickly and have more power than the high-speed one until it reaches approximately 75% of its max speed. The maximum power of each motor will be approximately the same.

 

[dogman dan]

I'll go out on the limb again.

The big difference in winds for hubmotors in 26" wheels, is not the torque. But the increase in efficiency, during that period when the vehicle is going less than 10 mph, with a good load in the form of heavy weight or hill or wind, makes a difference. The question is does that difference matter enough to sacrifice 5-10 mph of top speed? For the vast majority, its not worth the difference.

How big a difference? Not much. But if you have to stop on a mountain, pulling a trailer, with the wind in your face, you'll appreciate the lower rpm version. You might make it to the top with either version, or not, depending on how bad you have overloaded the vehicle. But in years of climbing a big mountain with a CA on the bike, I'm convinced the low rpm motor is more efficient overall. Again,,, part of why is you simply get up the mountain a few mph slower. You can see that you are pulling less watts at max speed up the grade, and you should, you are going about 2 mph slower. But when you watch the motor with a heat gun or internal thermometer, you do see the low rpm motor running cooler when you top out. This hill is 5 miles, the last two miles 7-8% grade.

That is a cooler motor up the hill, when all else was the same. Same hill, same weight, same controller, same battery, same weather.

It's a big hill, and measuring the wh taken to get to the top, the difference is really quite small. Its a mountain, and you never get up it cheap. It's about 50w less to the top using the slower motor. Sounds like not much, and it's indeed it's not much. But 50wh worth of less motor heating can be crucial. With 50 miles with no water, no plugs, nothing but burning desert on the other side of that mountain, 50 wh more range on the other side is mighty nice. It might mean pedaling the last two or three miles to a plug, or not. But most don't try to ride an ebike across a desert like that. So the 50 wh usually does not matter at all.

 

[MadRhino]

...The units for power are foot*pound per second, ft*lb/s, aka ft lb/s, aka ftlb/s.

Sorry Mike, it is the unit for torque that is (Nm) in metric system or (ft lbs) in US system
The unit for power is the Watt or HP

 

[chas58]

...The units for power are foot*pound per second, ft*lb/s, aka ft lb/s, aka ftlb/s.

Sorry Mike, it is the unit for torque that is (Nm) in metric system or (ft lbs) in US system
The unit for power is the Watt or HP

I think Mike had it right. Mad Rhino looks to be mixing units.

Torque is a force that causes rotation. Thus it is lever arm x force (ft-lbs)
Power is torque over time. 1HP = 550 ft-lb/s (foot-pounds (torque) per second). (i.e. 745.7 watts).

So yeah, power is HP. HP is ft-lb/s.

Torque is the force, Power is that force causing movement, velocity.

Interestingly without movement you can have high torque and no power.
An electric motor creates its highest torque at zero RPM, but it has zero power at zero rpm. WIth no movement, there is no power.
You can see that in the graph above, where we have a peak of 80 Newton-Meters torque at zero rpm and thus zero Watts power.

 

[dogman dan]

Foot pounds for US, but the rest of the world measures torque in newton meters.

 

[MrDude_1]

Foot pounds for US, but the rest of the world measures torque in newton meters.

Its ok. we just change whatever they say into ft-lbs, Fahrenheit, or miles... then answer with those units. :lol:

 

[markz]

But then you just go a tad slower up that hill in a fast wind. Then both are equal.
Efficiency is a good angle to look at.
There is another angle I will look into, and see what the "Guru's" say. Its late and I am yawning like crazy, but it has to do with Amps per something, wind, strand. Off to sleep I go.

I'll go out on the limb again.

The big difference in winds for hubmotors in 26" wheels, is not the torque. But the increase in efficiency, during that period when the vehicle is going less than 10 mph, with a good load in the form of heavy weight or hill or wind, makes a difference. The question is does that difference matter enough to sacrifice 5-10 mph of top speed? For the vast majority, its not worth the difference.

How big a difference? Not much. But if you have to stop on a mountain, pulling a trailer, with the wind in your face, you'll appreciate the lower rpm version. You might make it to the top with either version, or not, depending on how bad you have overloaded the vehicle. But in years of climbing a big mountain with a CA on the bike, I'm convinced the low rpm motor is more efficient overall. Again,,, part of why is you simply get up the mountain a few mph slower. You can see that you are pulling less watts at max speed up the grade, and you should, you are going about 2 mph slower. But when you watch the motor with a heat gun or internal thermometer, you do see the low rpm motor running cooler when you top out. This hill is 5 miles, the last two miles 7-8% grade.

That is a cooler motor up the hill, when all else was the same. Same hill, same weight, same controller, same battery, same weather.

It's a big hill, and measuring the wh taken to get to the top, the difference is really quite small. Its a mountain, and you never get up it cheap. It's about 50w less to the top using the slower motor. Sounds like not much, and it's indeed it's not much. But 50wh worth of less motor heating can be crucial. With 50 miles with no water, no plugs, nothing but burning desert on the other side of that mountain, 50 wh more range on the other side is mighty nice. It might mean pedaling the last two or three miles to a plug, or not. But most don't try to ride an ebike across a desert like that. So the 50 wh usually does not matter at all.

 

[dogman dan]

All hub motors are more efficient going slow. If the load is light, I can get the same wh/mi from my 6x9 as from my 9x7. Both in 26" wheel. Simply ride the same speed, and the difference in efficiency will be very hard to detect.

Where the low rpm effect works well is when forced to go slow by load. Take those same two 1000w systems and load them up. Add a trailer with 50 pounds in it, then ride through a city with plenty of stop signs, and some hills. Now you will see an obvious difference in efficiency. Enough stops, and it can reach 20% different. It's the difference in efficiency on all those stops that makes the difference. Repeatedly going less than 5 mph for a few seconds with a big guy or trailer, or whatever adding a lot of weight.

This is why E-bike kit sells the lower rpm DD motor for those with bikes that will weigh over 300 pounds. Tandems, trailers, cargo bikes. These generally are folks who don't intend to ride faster than 20 mph. Nobody buys that kit and comes back complaining the motor burnt out. This is good for us, no returns despite the heavy loads. Takes a lot of weight to burn out that motor in 9x7, but in 6x9 its even harder.

 

[thunderstorm80]

I thought I should reply too.
Guys, please listen to Justin
For the same motor family, they have the exact torque and power density.
You see "better" results with the slower wind because it needs less current to do so - and less current means lower resistive losses on the wire, ANY wire, and inside ANY controller.
This is where the 10% improvement come from.
The "price" is that the slower wind motor needs a higher voltage to do so.
If you compare two different winding motors with the simulator, you must provide the appropriate conditions for each of them (higher voltage&lower current and vice versa), otherwise your comparison is not fair!

If you want to build a system and maximize it's power-density and it's efficiency of converting between electrical and mechanical energy, here is the ultimate TRUTH, step by step:

1. Pick the highest voltage pack that is compatible with your controller, taking regen and "hot off the charger" voltages as the max values!
2. Choose the slowest winding motor that will still give you the top speed you desire.
3. BUT - the problem with slower wind motors, is that if you use a trapezoid controller like the Grinfineon, it can fry the motor's delicate phase-windings as it has no control over the phase current.
If you take a small Grinfineon (like 20A version), then you will be power limited for no reason...
4. Buy a phaserunner! With it, you control your phase-current, and dump the pointless battery current limit, giving you new horizon of available powers at higher speeds.
Read Justin's reply to what I wrote about the debate between phase-current limit to the useless input-power limit:
https://endless-sphere.com/forums/viewtopic.php?f=30&t=83239#p1226767
5. If you choose the H3525 that has one of the slowest windings out there, combine it with a high voltage (around 80V) with the Phaserunner, you lower ALL your wiring losses, controller heat losses (it's MOSFETs operate at very modest current as you don't need much to propel the H3525), and therefore decrease your overall losses. You maximize the Phaserunner power density, as well as the motor's.

Here are the numbers from my new E-bike build that runs 9C+ 2706 on the front, and ezee250rc on the rear. I use phaserunner to operate each motor.
I can cruise on flats at 60-70Km/h, while operating only on the 2706 with powers around 2KW. (twice than it's input-power "rating")
I climb any uphill, even those 12% we have here, at speeds of 50-60Km/h, using both motors - at powers of 4KW. Yes, four thousand watts
It's about 2000W at the ezee, and 2000W at the 2706. No, neither of them overheat, and they are barely warm to the touch after a long mountain climb at those conditions.
It's because I work by phase-current limits rather than battery current limits, and I exploit the fact that if my phase-current reaches a limit, and therefore my torque reaches a limit - but since Power=Torque*Angular-speed - I can get those high powers at higher speeds - which is where they are also needed...

If I would think back - I would have bought the 2707 (slower wind) instead of the 2706 - so I could exploit more sustained torque from the phase-runner with less heat losses. (especially at regen)