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Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 23 2019 4:54pm
by The Toecutter
neptronix wrote:
Aug 23 2019 4:35pm
Unfortunately leaf does NOT offer the lighter 27mm, so you'd have to go with MXUS or 9C and pray they'll provide you at least a 4T winding.
Has the efficiency of these caught up with the Leafbike motor yet? What about hysteresis and cogging losses? A few years ago when I researched these motors I remember them being not so great and the Leafbike being the best on the market. I'm now guessing the product landscape has changed a bit.

I highly value the ability to pedal the bike with the motor off and battery drained. It is of utmost importance that the vehicle's ability to move be independent of the electric drive. Effort required for a given cruising speed in pedal-only mode has to be comparable to a normal velomobile; I can tolerate increased mass and increased inertia losses during acceleration vs a normal velomobile, and a small loss in mechanical efficiency from the pedals to the rear wheel, but a good steady state cruising efficiency that doesn't feel like it is a labor to pedal the vehicle when the motor is disabled is what is desired. The Mitas MC2 moped tires, even though they are "low rolling resistance", may prove to be too lossy to pedal efficiently, but that will be something I have to try for myself since the data I seek doesn't exist in the public domain.

It would be nice if someone made a hubmotor with 95%+ efficiency and a weight of under 8 lbs. The technology IS there for such a thing. If only I had the tools to professionally build a motor from scratch... I suppose I could always do like Cedric Lynch during his youth and spend hundreds of hours to make a highly compromised but still functioning prototype of what I have in mind using basic tools laying around the house. It would take a few tries at my friend's shop to get the axle and freehub placement correct so that it would actually work on a bicycle's dropouts and for the gears/chainline to line up properly for it all to function. Have to start from somewhere though...

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 23 2019 5:29pm
by flat tire
I agree. Where are the 95%+ bicycle hubmotors? I will pay 4 digits for one.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 23 2019 5:40pm
by neptronix
I sent a bunch of emails to leafbike to try to convince them to produce a motor with 0.27 or 0.2mm lams, and yeah, that's exactly the kind of motor we need for velomobiles, recumbents etc.

I didn't get anywhere over the course of a few months. What would help is if some of you could ask them about 0.2 or 0.27mm stator motors :) they generally speak good english.

I have not seen an improved ebike DD hub motor since i discovered this motor. :roll: sad isn't it?

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 23 2019 6:07pm
by The Toecutter
neptronix wrote:
Aug 23 2019 5:40pm
I sent a bunch of emails to leafbike to try to convince them to produce a motor with 0.27 or 0.2mm lams, and yeah, that's exactly the kind of motor we need for velomobiles, recumbents etc.


I didn't get anywhere over the course of a few months. What would help is if some of you could ask them about 0.2 or 0.27mm stator motors :) they generally speak good english.
I will send them an email as well, and post it here when I do, along with any replies.
I have not seen an improved ebike DD hub motor since i discovered this motor. :roll: sad isn't it?
Sad as it is, it's also an opportunity. If only I had the financial resources to pursue it. With the Hub Monster out of production, there is nothing to fill the niche of a high-powered e-bike hubmotor that makes minimal heat losses and can put out a ridiculous amount of power per unit of motor weight. There is just nothing there.

Yet the demand is easily a few hundred units a year if the motor is also light enough for use in low-powered applications and inexpensive enough for someone to pay the premium for the extra few miles of range they will get versus the cost of adding more battery.

It's not inconceivable we could have a motor with 95% peak efficiency, less than 8 lbs total motor weight, that could do perhaps 25rpm/V, make 20 kW peak for about 30 seconds, and do 5 kW all day long without melting, while having a strong reinforced case that won't crack and a beefy axle that won't bend when someone puts a cassette with a 9T Capreo ring on the far end and mashes the hell out of the pedals while the motor goes full retard on torque. Some here would pay $1,000+ for such a motor, but truth be told, a motor manufacturer could probably sell such a thing at a profit for under $300 if their sales volume was comparable to that of the Leafbike units.

It's a really obvious piece of low hanging fruit to exploit that no one is plucking.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 24 2019 9:16am
by neptronix
The Toecutter wrote:
Aug 23 2019 6:07pm
I will send them an email as well, and post it here when I do, along with any replies.
Thanks for putting a vote in as well.
The Toecutter wrote:
Aug 23 2019 6:07pm
Yet the demand is easily a few hundred units a year if the motor is also light enough for use in low-powered applications and inexpensive enough for someone to pay the premium for the extra few miles of range they will get versus the cost of adding more battery.
It's a hard sell because there are so few of us building super long range bikes with small wheels. The smaller the wheel, the more the low hanging fruit design tricks make sense:

1) Reduce the pole count by ~20% and exchange some low RPM torque capability for significantly lower iron losses.
2) I'm sure it's possible to wind a stator flatter and better than leafbike/leafmotor does. It may be useful to change the stator's tooth shape to assist in this. Less poles/teeth also makes this easier. Reducing copper loss in this way would likely increase efficiency more than the jump to super thin lams.
3) 0.2mm lams, to reduce iron losses as far as possible so that said motor could even be happy running in a 16" bicycle wheel at 2000RPM+ without taking an iron loss hit from such a high RPM..
4) Use whatever magnets have the highest flux per lb to optimize weight.
5) Utilize some of the more conservative weight saving techniques justin at ebikes.ca uses on his all axle motors.

I'd imagine that you could have a 11-13lbs 93%-95% peak efficient 1.5kw continuous capable motor at the end of the day. The motor design would sacrifice peak power output for cruising ( low load ) efficiency.

The problem is the same as John in CR faced. There are not enough customers out there who could take advantage of such a motor. So the first step to getting our dream motor is to convert people to the recumbent darkside :mrgreen:

Such a motor would also perform very poorly in larger wheels - 24" and above. So we couldn't depend on anyone other than a very niche market being interested.

A couple of these tricks would benefit larger wheels, but not by much..

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 25 2019 11:15am
by The Toecutter
I've found a Leafbike motor with a 4T wind laced to a 20" rim available locally. When I get my first paycheck in from my new job, I will be paying a visit to look at it and if everything is good, purchase it without having to wait weeks or months for it to ship from China.

I so badly want to put one of these motors in my homebuilt velomobile.

Anyhow, a few simulations, planning to use a 21s4p pack of Panasonic 2170 batteries and a Phaserunner FOC controller at 77.7V, running everything at close to 4 kW peak, with roughly a 1.5 kWh pack.

Full throttle with me pedaling my ass off at 400W, yielding 78 miles range(I don't think I'd do 400W for that long though):

https://www.ebikes.ca/tools/simulator.h ... 100&hp=400

35 mph cruise with me inputting 100W, yielding 148 miles range:

https://www.ebikes.ca/tools/simulator.h ... =60&hp=100

30 mph cruise with me inputting 100W, yielding 209 miles range:

https://www.ebikes.ca/tools/simulator.h ... &kv=13.164


With a 20" wheel and the 30/39/52T crankset I have, I will be needing to source a 56T front ring and front derailleur post extension to get the highest possible gearing, as well as a 7sp freewheel that has a 32-11T spread. This would give me a speed range of 3.3 mph pedaling up a steep gradient at 60 cadence with the motor off, to 42.4 mph sprinting at 140 rpm, motor off or on, and the possibility of cruising at 30 mph in top gear at 99 cadence. Not quite the best gearing,as this will require a Schlumpf HS drive to really take advantage of this configuration's capabilities.

With a Schlumpf HS drive, the motor would then be under-spec'd. I'd then have to order a 3T wind Leafbike motor and a controller that can go to a higher voltage, and re-arrange the pack into 27s3p to take advantage of the gearing combos offered with the Schlumpf drive, which is where I'd start looking at the possibility of 90 mph top speeds and the theoretical capability to cruise on the highway at 55-60 mph with reasonable cadences(although given that it's a short wheelbase tadpole, even when I add full suspension and moped rims/solar race car tires all around, I'm probably not going to want to cruise at more than 45 mph, and only after installing hydraulic disk brakes on all 3 wheels activated with a single pull lever with thicker rotors).

So, running the ultimate configuration I'd like to have off of a 3T Leafbike motor and Phaserunner controller, increasing the battery size 22s4p, pedaling my ass off at 400W, controller possibly abused at 70A battery current and 90A phase current with a stout heatsink on it, it could reach a 90 mph top speed:

https://www.ebikes.ca/tools/simulator.h ... 0&kv=21.51

Cruise at 45 mph, 100W pedal input, yielding 98 miles range:

https://www.ebikes.ca/tools/simulator.h ... 0&kv=21.51

With almost 6 kW peak, I'd be looking at 0-60 mph in under 10 seconds. With a 90 mph top speed, which requiring only 118 cadence in top gear with the Schlumpf drive engaged, that would be very car-like performance with human power accounting for at least some of the propulsion through the vehicle's full operating range, and close to 10% of its load at 90 mph pedaling hard. At 45 mph, the efficiency would be the equivalent of more than 2,000 miles per gallon, and at 90 mph, more than 500 MPGe(not that I'd trust its safety at 90 mph!). The best part of the whole thing would be there would be no dependency on the motor or any range anxiety. At the flick of a switch, it's a normal velomobile that accelerates like a heavy HPV, but could still keep up with the cars on flat ground on city roads.

Not bad for a $200 Chinese motor. :mrgreen:

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 26 2019 11:10pm
by neptronix
You'd like the 3T, for sure.. :lol:

Here is a simulation of the 3T 30mm i have..

https://www.ebikes.ca/tools/simulator.h ... 20&kv=21.5

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Aug 27 2019 12:21pm
by The Toecutter
neptronix wrote:
Aug 26 2019 11:10pm
You'd like the 3T, for sure.. :lol:

Here is a simulation of the 3T 30mm i have..

https://www.ebikes.ca/tools/simulator.h ... 20&kv=21.5
Yeah, you're going to want full suspension and hydraulic disc brakes all around for that... :twisted:

Your simulation, at 33% throttle, also gives you 126 miles of range at 30 mph and 12 wh/mile at that speed. What kind of 76V 20AH battery will you be using?

When I get my next check, I'm going to pick that 4T motor up. That will be the first part needed to get me going on electric power, and depending on what the U.S. and China do regarding trade(or war with Iran), these motors may become hard to come by if the worst happens. My friend has his truck legal now and I just need to find a day to pick up the plastic I need to finish the next body shell prototype. Once I have the motor, controller, battery, charger, torque sensor, computer, and all the odds and ends to make it work as an EV, I will be adding a Schlumpf drive to get gearing for pedaling at the high end on a 20" rear wheel. I'm for sure going to lace the motor to a moped rim when the local bike shop is able to do that for me(they only do wheels in the winter), with 13ga spokes, and try a Mitas MC2 tire on just the rear wheel, continuing to run Marathon Greenguards on Velocity USA recumbent rims up front. I'll get to know whether or not it rolls easily enough unpowered for my needs, being that I want it ridable with the motor disabled. If I can maintain a 20 mph rolling average for 30 miles with the 4T motor and the next body shell installed while the drive system is shut off, I'll consider that good enough on that basis. Close to 60 mph top end with the motor on is also going to be plenty of speed for this trike.

Upgrading to handle 90 mph is going to take a lot more than just the right motor. Once I have it working as an EV, I can upgrade to rear suspension to turn it into a full suspension trike, put in some hydraulic disc brakes, then get moped rims laced up for the remaining wheels and try out some solar race car tires all around, build a roll cage out of tubing with my friend's tubing bender, and if the coroplast shape is correct regarding aero and other requirements I can make the same shell out of a more permanent material. THEN I will take it around and test it at its limits at top speed and see how that does.

Once everything is to my liking, the very last step will be swapping out the 4T to a newly ordered 3T wind Leafbike motor, given that the only advantage it will really give me is car-like top speed. I don't imagine I'll be using that speed often, but it would be a fun capability to have if I ever needed it, or for just hooning about in places where it is safe to do so.

Until then, the 4T wind still offers plenty of potential top speed for my needs, and I won't need to wait months for it to come in from China.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 01 2019 6:16am
by Tony01
I'm looking for a cheap 4-7kw peak front hub to complement the rear hub. Are the cheap 1000w and 1500w aliexpress DD motors the same as the leaf motors? This seller doesn't know how to give me accurate info about the product. Can only tell 30h and 35h but weights apparently are all at 6kg, and confuses phase wire gauge with motor cable length, smh. around $160.
https://www.aliexpress.com/item/32977867079.html

Which motor will do 5-6kw peaks lets say 3 or 4 hard pulls in under 3 minutes? As I understand the 1000w are 6kg and 1500w are 7.x kg? Can I get away with running a 1000w for lets say 5kw peaks? 3 pounds difference is a big deal.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 01 2019 7:55am
by qwerkus
TDCM takes custom orders. All the big names here in Europe (Stromer, Klever and so on) using DD hubs get their motors there. Maybe we could design a forum motor, 27mm large diameter DD hub, 5Kg max with thin laminations, and ask TDCM to produce it ? Won't be cheap though. Wenling 9c (producer of the RH212) also takes custom orders, and is much cheaper. All we need is around 100pcs collective order and someone willing to manage it. At $100/pc + costs for a new mold, we are talking USD12000 investment, plus maybe $1000 for the container shipment. If you sell them $200/pc, you'd still make a profit...

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 08 2019 12:18am
by The Toecutter
So I've arranged to take a look at and possibly purchase a used Leafbike motor kit with 4T wind this coming weekend.

I will have the opportunity to plug it up to a battery pack and test it. What items and potential problems should I be on the lookout for?

I don't plan to use the controller/display that comes with the kit long term, just as a placeholder to get me going when I find some sort of used/nearly free battery to use with it. I'm mainly concerned with the motor itself because once I get an appropriate controller, battery, and computer to allow such, I am planning to start off running it at a 4 kW input from the battery.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 08 2019 8:25am
by thundercamel
Without opening it, you could verify the 13.16 rpm/volt unloaded speed of the 4T winding...

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 08 2019 10:40am
by ZeroEm
At 4K the tempter sensor needs changing or need to put one in if not using the kit to match the one you will be using. That is if you want to motor to last.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 08 2019 11:16am
by The Toecutter
ZeroEm wrote:
Sep 08 2019 10:40am
At 4K the tempter sensor needs changing or need to put one in if not using the kit to match the one you will be using. That is if you want to motor to last.
Any recommended models of this temperature sensor?

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 08 2019 11:49am
by ZeroEm
Don't know enough to recommend. I know that the leafmotor handles 2k well but above that you need to watch the tempter. I bought pair of leafmotors at the same time. One came with a sensor installed and the other did not. The one with the sensor will not work with the CA3 but at least the wire is in the shaft. I have not opened this motor up to change the sensor I bought one from Grinn that I will be putting in. I know the stock sensor works with the leafmotor kit but not the CA3. I guess it depends on which LCD/computer you use and get a compatible sensor. Some have run at high watts and over heated the motor and weakened it.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 09 2019 2:21am
by Dumsterdave
ZeroEm wrote:
Sep 08 2019 11:49am
The one with the sensor will not work with the CA3 but at least the wire is in the shaft.
so what could we use to show a readout of the temperature instead? im looking for a cheap and easy option. I have a leafmotor with the temp sensor installed by leaf.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 09 2019 7:37am
by spinningmagnets
Here are some temp sensor options
viewtopic.php?t=25502

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 09 2019 10:31am
by The Toecutter
ZeroEm wrote:
Sep 08 2019 11:49am
Don't know enough to recommend. I know that the leafmotor handles 2k well but above that you need to watch the tempter. I bought pair of leafmotors at the same time. One came with a sensor installed and the other did not. The one with the sensor will not work with the CA3 but at least the wire is in the shaft. I have not opened this motor up to change the sensor I bought one from Grinn that I will be putting in. I know the stock sensor works with the leafmotor kit but not the CA3. I guess it depends on which LCD/computer you use and get a compatible sensor. Some have run at high watts and over heated the motor and weakened it.
Is it possible at all to make the one with the built-in sensor work with the CA3 by removing the sensor? I plan to use a CA3 with the one I get and need to make sure it is compatible, whether right away or with modification. I do not plan to use the stock controller for the kit in the long term.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 11 2019 10:34am
by ZeroEm
The CA3 needs a 10K NTC thermistor and I believe the one in the leafmotor is a 100k. anyone correct me if I am wrong.
If your motor is wired then open it up and replace the thermistor. That is what I plan to do with my 7T Rear leafmotor.
This was discussed somewhere I will look for it.

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 11 2019 12:17pm
by pwd
Leafbike tends to be all over with their temp sensors. My first one was KTY 84-130. For my second order, I requested a 10K NTC but they installed a 100K NTC. I had to swap it out for a 10K NTC so it worked with my eBay temp display. The Cycle Analys works with linear sensors as well:

viewtopic.php?p=1151914#p1151914

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Posted: Sep 11 2019 2:42pm
by The Toecutter
Thank you all for the info. The seller wants to meet a few weeks from now. I'll have plenty of questions that they may not know the answer to, but since it is possible to take the motor apart to install new components for my requirements, then I know I can make it work regardless of what it has in it.