Leaf / leafmotor / leafbike high efficiency 1500w motor

[neptronix]

I've begged the owners of leafbike and also grin for 0.27mm laminations but the answer has been no for years.
There would be limited to no benefit until you get around to a 20" wheel and you're pushing insane power/speed.

0.27mm lams would have some benefit in geared motors and mid drives but i cannot convince anyone to spend the extra $20 to get another few % of efficiency.

 

[ebike4healthandfitness]

I've begged the owners of leafbike and also grin for 0.27mm laminations but the answer has been no for years.
There would be limited to no benefit until you get around to a 20" wheel and you're pushing insane power/speed.

0.27mm lams would have some benefit in geared motors and mid drives but i cannot convince anyone to spend the extra $20 to get another few % of efficiency.

When you say insane power and speed what levels are you talking about?

I ask because Europe allows much higher power levels for their mopeds (4000 watts continuous with no limit AFAIK for peak power) compared to US (though max speed is still only 45 km/h (28 mph)):

STEALTH Electric Bikes Are Now Street Legal Mopeds in EU

Stealth electric bikes from Australia came to EICMA 2021. in style packing 2 NEW homologated electric mopeds, new 250W ebikes, and the older models! The company has shown city traffic-worthy versions of their popular electric

evnerds.com

4000 watt continuous power hub would be great for 20" cargo bikes.

 

[neptronix]

The 35mm wide leaf in a 20" wheel would likely have a 3000w continuous power limit before you even start adding cooling mods. 8kw peak no problem.

45kmh only uses 750w continuous so the only reason you'd need a motor with >3kw rating is if you have to climb mountains.. ferrofluid and a hubsink should handle the thermal part of that problem unless you're taking a huge load up a 10% grade for many km

 

[ebike4healthandfitness]

45kmh only uses 750w continuous so the only reason you'd need a motor with >3kw rating is if you have to climb mountains.

Head winds also matter. In fact going from no headwind to a 10 mph headwind almost doubles power requirements at 28 mph.

Another thing that matters is the form factor of the bicycle. (Example) According to Bicycle Speed (Velocity) And Power Calculator going from an "unsuspended mtn bike" to a "roadster" increases power consumption 32% at 28 mph. This when keeping rider size (6' 170 lb) and tire type (wide high pressure slick) the same.

A "roadster" needs almost 1000 watts to hit 28 mph on flat ground. Throw in a headwind and that number can increase beyond that by a good amount.

P.S. Obviously adding bags to the roadster will only make its power consumption (either with headwind or no headwind) climb even more.

 

[neptronix]

Watt usage of leaf 1.5kw in a regular bike with 20's right at the ridge of the high efficiency band:



375lb ( 170kg ) upright fat bike ( least aerodynamic bike on the simulator )



Going up a 7% hill.



You probably need more like a 2.5kw peak. And a more stout battery than what's specified here.

 

[ebike4healthandfitness]

So 736 watts for 20" non fat mtn bike (in a tuck) at 47.5 km/h.

This compared to 990 watts for 20" fat bike in upright riding position at 45 km/h.

That almost looks exactly like the relationship of an unsuspended mtn vs. roadster in the calculator I posted.

If adding in just one set of rear panniers to the 20" fat bike (let's assume it is in the form of a 20" fat cargo bike) and I would expect power consumption to be at least 1200 watts at 45 km/h. Add in front rack plus bulky bag (like the one shown below) plus front panniers and power consumption would likely be 1350 watts or more.

 

[ebike4healthandfitness]

The 35mm wide leaf in a 20" wheel would likely have a 3000w continuous power limit

If I am at 1350 watts or more just to hit 28 mph on flat ground with no headwind I honestly wonder how far 3000 watts continuous would really take me?

Added cargo weight plus a hill? Even just a small grade with no headwind could eat away that 3000 watt budget pretty fast.

Then the other question becomes how efficient is the 1500 watt leaf bike motor going to be at 3000 watts continuous? Wouldn't the added heat reduce efficiency compared to running 1500 watt continuous or even 2000 watt continuous?

 

[neptronix]

You aren't going very fast in this case so the aerodynamic penalty shouldn't be too much worse than expected.
That's why i added a 25% buffer in and said 2.5kw instead of 2kw

 

[neptronix]

If I am at 1350 watts or more just to hit 28 mph on flat ground with no headwind I honestly wonder how far 3000 watts continuous would really take me?

Added cargo weight plus a hill? Even just a small grade with no headwind could eat away that 3000 watt budget pretty fast.

I modeled that and that's where i got 2kw

Then the other question becomes how efficient is the 1500 watt leaf bike motor going to be at 3000 watts continuous? Wouldn't the added heat reduce efficiency compared to running 1500 watt continuous or even 2000 watt continuous?

Motor Simulator - Tools

It hits 2700w on a 10% grade and is 75% efficient at that point. It could tolerate this for some time with ferrofluid and hubsinks but not forever obviously.

On a 7% grade with ferrofluid and hubsinks you'd be at 80% efficiency which is enough to do indefinetely with ferrofluid and hubsinks.

Mostly the weight is hurting you in this hill climbing scenario and not aerodynamics.

Play with the simulator link provided above, it'll answer further questions.

PS this particular winding on the ebikes.ca simulator is significantly less efficient than the 4T, so i'm being pessimistic here.

 

[ebike4healthandfitness]

You aren't going very fast in this case so the aerodynamic penalty shouldn't be too much worse than expected.
That's why i added a 25% buffer in and said 2.5kw instead of 2kw

Actually the research I saw for power consumption penalty added by one set of panniers (20% penalty at constant speed) was measured at just under 20 mph. Your example at 36.4 km/h (22.5 mph) is actually at a speed higher than this therefore I believe my conservative estimate of 20% (for one set of panniers) at 45 km/h definitely holds at your speed as well. Obviously adding another set of panniers and front rack with bag adds even more power demand. I am guessing an additional 150 watts at 45 km/h but honestly I wouldn't be surprised if it is much more.

But with that noted, why climb a hill at only 36.4 km/h (22.5 mph) when the legal limit is 45 km/h (28 mph)?

Better idea is make sure much more continuous power is available.

 

[Bullfrog]

I drilled holes in mine in ~2014 and proved that with some mild air cooling i could sustain 40mph indefinitely.

The motor is >85% efficient still at 40mph ( ~2000W ) so there isn't a serious heat problem at that speed.

Ferrofluid would be adequate over drilling holes in the motor for this purpose.

Nep,

How many holes did you drill in each side cover and what diameter holes?

What did you use to drill them?

Over the last few days, I went back and read EVERY one of Justin's posts in the "Definitive Tests on the Heating and Cooling of Hub Motors": Definitive Tests on the Heating and Cooling of Hub Motors and along with my experiences trying ATF and Water/Motul MoCool as a cooling fluid, I am finished with anything liquid inside my motors...just too difficult to seal the motor and keep it from leaking. I didn't believe Justin when he told me that cooling fluid will run out of the wiring (due to capillary action) but after getting ATF on my rear brake disc via the wiring, I am a believer.

Now I want to try some "enhanced" air cooling techniques...drill my side covers and maybe put small NACA ducts over the holes with the ducts facing forward on one side and rearward on the other along with a fixed scoop mounted on my frame on the side with the ducts facing forward to direct more airflow towards the motor.

Sending Leaf a message shortly to see if I can buy a set of side covers...I'd like an extra set just in case I want to go back to the original configuration at some point.

Edit...did you separate the side covers from the motor to drill them?

Thanks

 

[Bullfrog]

Has anyone else drilled holes in the side covers of your Leaf motor?

If yes, please briefly elaborate how you did it, how many holes, what diameter, etc.

Thank YOU

 

[E-HP]

Has anyone else drilled holes in the side covers of your Leaf motor?

If yes, please briefly elaborate how you did it, how many holes, what diameter, etc.

Thank YOU

From this thread, pics don't display:

Leaf / leafmotor / leafbike high efficiency 1500w motor

Did ZombieSS chime in? because he showed that PWM = more controller heat = less efficiency. Maybe it's just a few percent? but why lose a few percent of efficiency if you can avoid it, eh? Of course a lower turn count can handle more battery/phase amps. It needs them to produce the right amount...

endless-sphere.com

Definitive Tests on the Heating and Cooling of Hub Motors

The EDF design could also be improved by adding an external duct because the exhasut and intake air holes are on the same side. This causes a decent amount of exhaust air being sucked back into the motor. I had planned to make this with a 3d printer but never got around to actually doing it...

endless-sphere.com

Not on the Leaf, but just for example; includes cooling fans (I'm glad I found this post, since the motor has the same low profile heat sinks that I'll be adding and comparing pre and post temp data against):

Leaf / leafmotor / leafbike high efficiency 1500w motor

Did ZombieSS chime in? because he showed that PWM = more controller heat = less efficiency. Maybe it's just a few percent? but why lose a few percent of efficiency if you can avoid it, eh? Of course a lower turn count can handle more battery/phase amps. It needs them to produce the right amount...

endless-sphere.com

 

[neptronix]

20 seconds in you will see the cooling holes. Yes, i took the plates off, you don't want aluminum debris in your motor. You don't want to accidentally drill into your windings.

I wouldn't do this again, i'd use ferrofluid and hubsinks. We have a lot of crap on the road that i don't want getting into my motor. We also have occasional dust storms.

These cooling holes allowed me to do 45mph continuous for very long periods of time - maybe indefinitely.

 

[Bullfrog]

From this thread, pics don't display:

Leaf / leafmotor / leafbike high efficiency 1500w motor

Did ZombieSS chime in? because he showed that PWM = more controller heat = less efficiency. Maybe it's just a few percent? but why lose a few percent of efficiency if you can avoid it, eh? Of course a lower turn count can handle more battery/phase amps. It needs them to produce the right amount...

endless-sphere.com

Definitive Tests on the Heating and Cooling of Hub Motors

The EDF design could also be improved by adding an external duct because the exhasut and intake air holes are on the same side. This causes a decent amount of exhaust air being sucked back into the motor. I had planned to make this with a 3d printer but never got around to actually doing it...

endless-sphere.com

Not on the Leaf, but just for example; includes cooling fans (I'm glad I found this post, since the motor has the same low profile heat sinks that I'll be adding and comparing pre and post temp data against):

Leaf / leafmotor / leafbike high efficiency 1500w motor

Did ZombieSS chime in? because he showed that PWM = more controller heat = less efficiency. Maybe it's just a few percent? but why lose a few percent of efficiency if you can avoid it, eh? Of course a lower turn count can handle more battery/phase amps. It needs them to produce the right amount...

endless-sphere.com

20 seconds in you will see the cooling holes. Yes, i took the plates off, you don't want aluminum debris in your motor. You don't want to accidentally drill into your windings.

I wouldn't do this again, i'd use ferrofluid and hubsinks. We have a lot of crap on the road that i don't want getting into my motor. We also have occasional dust storms.

These cooling holes allowed me to do 45mph continuous for very long periods of time - maybe indefinitely.

Thanks again guys.

I found a video that showed a guy disassembling his Leaf motor and I could see the inside of the side covers have ribs that divide it into 9 pie sections. Unless I change my mind after opening my motor, I plan to drill fairly large diameter holes in pie sections 1,2,4,5,7,8. That will give me six holes and three pie sections without holes...so everything will be symmetric...plus it will be stronger than if I drilled large holes in all 9 pie sections.

Nep, I hear ya on the dirt/trash on the road and I don't disagree. That is one reason I chose to try ATF and water/MoCool. Since I know I am going to need additional cooling, for me it comes down to a choice of Statorade or drilling the covers and adding at least a fixed scoop mounted to my bike frame. Statorade has a carrier fluid that is similar to kerosene based on everything I have read and kerosene will slowly evaporate leaving the sold particles of Iron behind. Over time, it may be difficult to keep the correct liquid to solids ratio (viscosity may increase) plus I'll need to seal the side covers...hopefully since so little Statorade is required, it won't ever get into my wiring and leak via capillary action.

I don't like drilling holes due to the contamination and Statorade has the challenge of evaporation plus leaking so since I have never tried additional air cooling before, figured it is time to give it a try. Hopefully I can get an extra set of side covers so if I ever want to go to Statorade without drilled side covers, the extra set will allow me to do it.

Right now I am waiting on the XT90 to 6mm ring adapter so I can connect my battery to the controller...hopefully everybody will be safe from further questioning until the adapter gets here .

Below is a pic of the inside of one of the side covers I found via one of the links that E-HP provided:

 

[ebike4healthandfitness]

In an effort to answer my question in post # 2774 ---> Leaf / leafmotor / leafbike high efficiency 1500w motor

How about comparing Clyte 4xx to Nine Continent 28xx?

Clyte 4xx: 40mm wide stator at PCD of 172mm (i.e. same PCD as Mac Motor/GMAC).

Nine Continent 28xx: 27mm wide stator at PCD of 232mm.

Weight of Clyte 4xx: 6.5 kg
Weight of Nine Continent 28xx: 6.1 kg

According to all the reports I have read here at ES both motors have essentially the same performance at the same wheel diameter.

If I were to wager a guess I would expect a 35mm wide stator direct drive hub with the same small diameter as the Mac Motor/GMAC would do very well. Obviously it wouldn't be as powerful as 35mm wide stator at 232mm PCD but not all bikes need the power of a 232mm PCD 35mm stator DD motor. Furthermore, the smaller diameter PCD allows for more lacing options to (and for) smaller diameter rims which are becoming more and more popular these days.

P.S. Looking through the Leaf bike catalog I found this 10" scooter kit with direct drive motor:

10 inch electric scooter motor - bike conversion kits

Convert your 10 inch scooter to electric scooter with leaf 10 inch hub motor bike conversion kits.

www.leafbike.com

So I'm guessing they already have a motor with the characteristics I mentioned in this post.

 

[ebike4healthandfitness]

Here is a picture of the Vector Vortex:


What if Instead of that big 232mm PCD Direct drive motor it instead used a smaller ~172mm PCD 35mm stator DD Leaf bike motor? This to allow for a protective shroud around the motor instead of it being exposed like you see above?

At what level of development does it need to be at in order to beat Stealth B52s (which has 50mm stator, .35mm laminations and PCD of 232mm) in the EU class 1 moped category (which limits continuous power to 4000 watts and top speed on public roads to 45 km/h but has no limit AFAIK to max (i.e. peak) power)? Currently B52s is listed at 2500 watt continuous power and 6200 watts peak power:

STEALTH Electric Bikes Are Now Street Legal Mopeds in EU

Stealth electric bikes from Australia came to EICMA 2021. in style packing 2 NEW homologated electric mopeds, new 250W ebikes, and the older models! The company has shown city traffic-worthy versions of their popular electric

evnerds.com

.27 mm laminations?

.20 mm laminations?

 

[Bullfrog]

Here is a picture of the Vector Vortex:

View attachment 351074
What if Instead of that big 232mm PCD Direct drive motor it instead used a smaller ~172mm PCD 35mm stator DD Leaf bike motor? This to allow for a protective shroud around the motor instead of it being exposed like you see above?

At what level of development does it need to be at in order to beat Stealth B52s (which has 50mm stator, .35mm laminations and PCD of 232mm) in the EU class 1 moped category (which limits continuous power to 4000 watts and top speed on public roads to 45 km/h but has no limit AFAIK to max (i.e. peak) power)? Currently B52s is listed at 2500 watt continuous power and 6200 watts peak power:

STEALTH Electric Bikes Are Now Street Legal Mopeds in EU

Stealth electric bikes from Australia came to EICMA 2021. in style packing 2 NEW homologated electric mopeds, new 250W ebikes, and the older models! The company has shown city traffic-worthy versions of their popular electric

evnerds.com

.27 mm laminations?

.20 mm laminations?

My understanding is that Stealth is now using the Crystalyte H55xx motor and for a rough approximation it should give you about 1.5 times the power of a Leaf motor...my crude estimate is only based on the difference in stator widths...35mm for the Leaf and 55mm for the Crystalyte. The specs on the Crystalyte motor are available here: pmdc cc

Weight is the opposite...the Leaf weighs ~16.2 lbs and the Crystalyte weighs ~19.8 lbs. I got both numbers by emailing the manufacturers.

FWIW, it is probably more appropriate to use the stator diameter instead of the PCD when making comparisons. They are usually related fairly closely but depending on the design they could be significantly different.

I wouldn't pay too much attention to the rated power/wattage, read this for an explanation:

Futility of Motor Power Ratings

Laminations thinner than .35mm are going to be pretty difficult to find and if you can find a motor that uses thinner laminations, they are probably going to be pretty pricey.

This video from Grin Tech is very good and Justin touches on all the different losses in an electric motor. It is fairly long and I had to watch it a couple times to absorb and understand everything:

Is there a particular goal you are trying to accomplish or are you just curious about the theory?

 

[Bullfrog]

When asking questions about why any manufacturer doesn't upgrade stuff, you have to remember the mighty Dollar (US and Chinese) makes the world go around and there are a LOT more ebikes sold in China than any other country on this planet. $10 is not that much to most of us but when you are running a business and trying to make a profit it is a different story. For example, if it cost $10 to upgrade a widget that means it will cost $10 million per year if you produce a million widgets per year. If you ran a business, would you be willing to spend $10 million with no guarantee you will recoup your investment much less make a profit?

We as Americans forget that a global perspective can be very different from our perspective and since we make up less than 5% of the worlds total population, our perspective can be almost irrelevant when it comes to world wide sales .

OK I am finished ranting...and I do appreciate and want to thank Neptronix/Everyone that has attempted to get Chinese manufacturers to make improvements.

 

[Bullfrog]

Got a response from Leaf regarding purchasing new side covers for my Leaf 1,500w Freewheel motor and they quoted $40 for a set of side covers...not too bad BUT shipping would be an additional $53 so $93 total.

I plan to drill the side covers currently on my motor and only buy another set if someone is willing to send me their old ones...I'll give you $20 and cover the shipping if anyone has a set of side covers for a Leaf 1,500w "Freewheel" (not a cassette) motor they are willing to get rid of .

 

[E-HP]

plus I'll need to seal the side covers...hopefully since so little Statorade is required, it won't ever get into my wiring and leak via capillary action.

Note that you don't need to seal your motor, or even open it. With my MXUS, I drilled and tapped a hole in the sidecover, squirted it in, and plugged it with a set screw. With my Leaf, I opened the motor to add the temp sensor and apply the Statorade. That was a lot more satisfying (pretty cool how it flows by itself). You can see when you apply it that it's not going anywhere, and it's only a few cc's, and not enough to even make it to a seam that would leak. I'll be tearing down my motor to inspect the windings and re-apply Statorade (8k miles, so overdue), hopefully next week. I'm hoping it will look pristine, even after being subject to some mild abuse.

 

[neptronix]

Smart setup, i remember Justin suggesting this. Curious to see the insides!

 

[ebike4healthandfitness]

When asking questions about why any manufacturer doesn't upgrade stuff, you have to remember the mighty Dollar (US and Chinese) makes the world go around and there are a LOT more ebikes sold in China than any other country on this planet. $10 is not that much to most of us but when you are running a business and trying to make a profit it is a different story. For example, if it cost $10 to upgrade a widget that means it will cost $10 million per year if you produce a million widgets per year. If you ran a business, would you be willing to spend $10 million with no guarantee you will recoup your investment much less make a profit?

We as Americans forget that a global perspective can be very different from our perspective and since we make up less than 5% of the worlds total population, our perspective can be almost irrelevant when it comes to world wide sales .

OK I am finished ranting...and I do appreciate and want to thank Neptronix/Everyone that has attempted to get Chinese manufacturers to make improvements.

Don't forget there is a need for higher end ebikes as well. Otherwise we wouldn't be seeing developments in hub motors like Mahle x20 (a tiny integrated wireless torque sensing hub motor.)



Besides what has been mentioned in the thread I think thinner laminations is going to help durability of hub integrated batteries, controllers and sensors as well. This especially in hub motors that are smaller than what we normally see.

I know the vast majority of people here (in this forum) don't like integrated hub motors but I have been seeing them become more popular. You mention the Chinese market we'll here are two that came out in 2023:

P130 ALL-IN-ONE Rear Motor

ALL-IN-ONE: Built-in battery, controller, sensor, connection module, etc.

keyde.com

P160 ALL-IN-ONE Rear Motor

ALL-IN-ONE: Built-in battery, controller, sensor, connection module, etc.

keyde.com

(I also really like how the battery inside the hub motor charges via a 100 watt usb-c pd port--> PD Charger. 100 watt USB-C opens up so many possibilities including power bank usage when not close to a power outlet.)

Note despite being a geared hub motor they are still advertising 90% efficiency (which AFAIK is best in class. Besides this Keyde at 90% the best efficiency I have ever seen for a geared hub motor was 87%). My guess is the extra efficiency is there to keep the temperature sensor from shutting down the integrated controller during high heat conditions.

I've read Keyde has been persisting with these all-in-one hub motors for something like 10 years. If there was no demand for them in the Chinese market and elsewhere I don't we would still see them releasing new versions.

With that noted I don't think there is currently an all-in-one direct drive hub motor on the market.

 

[amberwolf]

My guess is the extra efficiency is there to keep the temperature sensor from shutting down the integrated controller during high heat conditions.

You would not want anything to keep a sensor from doing that, if the system is overheating, it should rollback, shutdown, etc., to reduce heat output to not damage parts. (especially if the battery is inside it).

Making something more efficient to reduce the heat created in the first place would be good, though; if that's what you meant.

 

[ebike4healthandfitness]

FWIW, it is probably more appropriate to use the stator diameter instead of the PCD when making comparisons. They are usually related fairly closely but depending on the design they could be significantly different.

Indeed. A good example would be the nine continents (and numerous other direct drive hubs) that use a PCD of 232mm with a 205mm diameter stator as compared to the PCD of 214mm the Grin all axle motor uses with the same 205mm diameter stator.