Leaf / leafmotor / leafbike high efficiency 1500w motor

[John in CR]

Fanciful imagination??? Your ridiculous refusal to understand such a simple concept is astounding. The thing I have a real problem with is that it turns into erroneous advice, and that's why people burn up motors since they have no idea of the real current limits. I've never burned one up, despite for 12yrs having higher performance than virtually anyone on the forum, and climbing steeper hills hauling heavier loads, and doing that all at a cheaper cost than the vast majority.

A 3 turn motor will meet the needs of the overwhelming majority using the common voltage range of 24-48 volts, and throw in 72V for the guys wanting really high top speed. I begrudgingly added the 6t as an option just for those who want to go really slow and 24V is still too fast. That would result in widely know current limits, not an unknown current limit for every different wind, which would mean the end of burned up motors.

FYI, the DD hubbies I started with in 2008 were from the factory that holds the Chinese patent for the now so common 46 magnet 51 slot motor (like Leaf, MXUS, 9 Continents, etc), and they sold exactly 1 motor winding, a 2 turn, which is a bit too hard on cheap controllers due to the low inductance. The resulting Kv is also a bit too high even at 24V for those wanting to go slow without running a tiny wheel. With a $125 combo including motor, controller, moto rim, and DC/DC converter, I was climbing mountain roads just as efficiently as your slow wind, while carrying heavier loads and probably enjoying better acceleration. The real limiting factor back then was controllers, and there's a lot more better bargain controllers available now. Just don't try driving a heavy DD hubbie with a controller meant for a crappy little geared hubbie.

 

[ZeroEm]

I need to read back thru but did anyone buy and get the 4T leafmotor they were talking about?

 

[Peter Svancarek]

Hello...I don't want to create new thread since I have similar question...
I want to build tricycle with pedal electric transmission- PEDELEC type. I have build tricycle with chain only transmission and the chain-link is consisting of 2 pulleys and it needed 3 full bicycle chains to connect pedals with rear wheel. So, this is my motivation- to get rid of the chain, and to have possibility of regenerative braking and even reverse drive.

The projected tricycle will have probably about 125 - 130kg with driver.

Due to laws in my country I don't want to make something that would be too provocative, therefore I don't want the max speeds higher than 35km/h and I will drive normally only up to 25km/h on road. I can't do anything with power restriction, as 250W is too low for engine to propel the trike. But I saw the Bike2 presentation which uses 750W engine of BAFANG in their pedal electric transmission. I don't like much the geared hubs, those gears made of plastic... and under high load which will be there when no chain will be there to help...
What I need from direct drive hub motor is torque... which I will get in two ways- motor power, and wheel radius. I have no problem with radius 16 or even 12 inch.

I have been in communication in Leaf company - they think that I should use 2x 1000w engine instead... https://www.leafbike.com/products/diy-bike-conversion-kit/14-inch-48v-52v-1000w-front-casted-electric-scooter-motor-kit-1191.html I don't like the two engine solution much... the mass, the price, the control of two front hubmotor wheels.
They have written me, that this engine has 40 N.m at 40 amps. Which translates to about 225N of thrust(at the mass 130kg this should allow to climb up to 17% hill??? No more than 15% hill is around, and I don't need to use that route anyway). But at 48V and 40A the power input would be nearly 2000W??? Also, they have written that they can customize winding for lower speed- does that mean that it will give the motor higher torque? I thought that different winding will only change usable voltage/current ratio. So, if more turns of thinner cable is used then I would be able to use higher voltage but lower current. I don't understand this much.

The 1500W hubmotor is unable to utilize less than 20 inch rim. That is pity.... maybe I would be able to get there 16 inch rim but it would be impossible to lace such wheel. I would need to make some kind of aluminium rings, but to make them concentric would be hard and to set it nearly impossible, so 20 inch is the lowest I could do without going into unnecessary problems.

I asked about their controller- they don't use sine wave controllers- they use square wave instead. That is lowering the power and efficiency of engine, I think... more heat generated is not good thing. But they got up to 90.5%efficiency even with square wave controller- impressive. It should be possible to use different controller.

So... what are your thoughts about this? Would be one hubmotor 14inch/52V with 40amp controller enough? I'm not sure about overheatings.
With regards Peter Svancarek

 

[thundercamel]

I wouldn't try syncing power between left and right hub motors. This is a tadpole trike, not a delta trike, correct? Easy option would be a hub motor in the single rear wheel, or a BBS02 (or equilivent) between the pedals. Hub motors can be direct drive or geared.

I use 1500w motors in 26" and 700c wheels, and it's plenty of power to get me around. 1500w in a 20" wheel would be even better, as long as it's the faster 4 turn wind. Speaking of choosing windings, that's a can of worms for discussion. It changes the Kv or RPM/volt of the motor. Lots of people think it's a major decision based on your battery voltage, wheel size, and hill grades, but it's a safer bet to go with the faster winding so you don't limit your top speed. More windings doesn't make a better hill climber and barely changes efficiency while doing so. Stick to the basic facts like this.

Sine and square wave controllers have similar efficiency, believe it or not. Yes, one 20 inch 52 volt 40 amp controller would be plenty, and won't easily overheat without a huge hill to go up. Would probably overheat the battery first, depending on what battery you choose.

 

[Peter Svancarek]

I wouldn't try syncing power between left and right hub motors. This is a tadpole trike, not a delta trike, correct? Easy option would be a hub motor in the single rear wheel, or a BBS02 (or equilivent) between the pedals. Hub motors can be direct drive or geared.

Thank you, it was mine opinion as well. It will be tadpole. The mass distribution will be approximately 33% per wheel. I'm aware of geared hubs, but I thin'k those wouldn't be good for this application... Unless I would change all the plastic gears for metal. And even then, when looking on their construction, I think they would have problems with cooling at higher load.
I don't want to use BBS02 because I want to get rid of the chain.

I use 1500w motors in 26" and 700c wheels, and it's plenty of power to get me around. 1500w in a 20" wheel would be even better, as long as it's the faster 4 turn wind. Speaking of choosing windings, that's a can of worms for discussion. It changes the Kv or RPM/volt of the motor. Lots of people think it's a major decision based on your battery voltage, wheel size, and hill grades, but it's a safer bet to go with the faster winding so you don't limit your top speed. More windings doesn't make a better hill climber and barely changes efficiency while doing so. Stick to the basic facts like this.

Thank you for sharing your experience. So the 1500W in 20inch wheel looks solid. I can choose winding according to the motor fill- to maximize amount of copper conductors in it.
What about 1000W hubmotor in 14 inch wheel? That engine is smaller and lighter. I tried to approximate the motor characteristics and fill them into simulator. It told me that that motor should climb 15% hill at speeds about 25km/h which is plenty for me. Of course, I approximated a few things I didn't have data for(like number of poles) so the reality may be worse. But still they wrote that it should provide 40Nm which is in my opinion plenty enough for 14 inch wheel(over 225N thrust). The controller they suggested would make it go to about 2000W, but for a few minutes at max it should survive without problems.

Sine and square wave controllers have similar efficiency, believe it or not. Yes, one 20 inch 52 volt 40 amp controller would be plenty, and won't easily overheat without a huge hill to go up. Would probably overheat the battery first, depending on what battery you choose.

Again thank you. I thought that Sine Wave controller is better because I have read about it... it looked logical, since when the engine changes to generator it produces sine wave naturally.
The worst climbing I can think off has about 500 meters of length with hill up to 14-15%. I was climbing it regularly on my purely muscle driven bicycle when there was no bicycle lane available. But the lane was build this year so there is no real need of that... unless I would want to try that... there is a few similarly long hills around but with about 8-12% climbing rate. Otherwise the country is relatively flat.

 

[thundercamel]

What about 1000W hubmotor in 14 inch wheel? That engine is smaller and lighter. I tried to approximate the motor characteristics and fill them into simulator. It told me that that motor should climb 15% hill at speeds about 25km/h which is plenty for me.

The Leaf 1000w is a little skinnier, little lighter. 30mm stator vs. 35mm for the 1500w. I don't think the diameter is any different though, and would probably need at least a 20" wheel. I'm surprised you're willing to go with such a small diameter, which must be rough over the bumps at speed. Even Golden Motor MagicPie only goes down to 18".

 

[Peter Svancarek]

What about 1000W hubmotor in 14 inch wheel? That engine is smaller and lighter. I tried to approximate the motor characteristics and fill them into simulator. It told me that that motor should climb 15% hill at speeds about 25km/h which is plenty for me.

The Leaf 1000w is a little skinnier, little lighter. 30mm stator vs. 35mm for the 1500w. I don't think the diameter is any different though, and would probably need at least a 20" wheel. I'm surprised you're willing to go with such a small diameter, which must be rough over the bumps at speed. Even Golden Motor MagicPie only goes down to 18".

https://www.leafbike.com/products/e-bike-hub-motor/14-inch-48v-52v-1000w-front-casted-hub-motor-electric-bike-wheel-1157.html The motor must have smaller diameter.
On the picture is tricycle I build last year- rear wheel is 20"; front wheels are 16". No problems with the sizes whatsoever. In fact, with smaller wheels it has better acceleration, and it glides very smoothly on tarmac. I have driven it also through gravel(it is pretty intensive as the stones are flying all around me ) and less than ideal roads without problems. I also made small wooden bike for steering geometry tests= with 12inch big wheels. Again it was able to drive without problems with roads(thats natural) but also on gravel and field-paths. Of course, the deep holes must be avoided... but the same would be true with larger wheels. Tricycle can't be driven the same way as bicycle, I can't jump with tricycle over the road bumps.

It would be relatively easy to rework rear end of this trike and utilize larger and stronger 1500W engine in 20 inch wheel... but that engine also allows for faster speeds and is heavier which I find unnecessary. With smaller wheel I would have lighter and slower solution still able to get over 35km/h which I wouldn't be able to use much. As I said, there is legal speed of 25km/h therefore thats the speed I will drive with most of the time at max. Well I rode 45km/h on this pedal driven tricycle without problems... but for electric bicycle this law applies.

 

[ZeroEm]

If getting rid of the chain is important stick with the 1500w 4T or 5T motor in a 20" wheel. 25 - 40amps and pick your Voltage to get the speed. 36v seems slow and 48v would work fine. Want more speed go up to 52v all of them should be enough.

Wider motors have more torque.

 

[Peter Svancarek]

If getting rid of the chain is important stick with the 1500w 4T or 5T motor in a 20" wheel. 25 - 40amps and pick your Voltage to get the speed. 36v seems slow and 48v would work fine. Want more speed go up to 52v all of them should be enough.

Wider motors have more torque.

Yes this looks like safe option. I will see what the Leaf will say about that 14nch engine, but 20inch wheel seems most realistic solution right now.
The 36V battery (probably LiFePO4 type, since it has more lifecycles and safety, even if it is a bit less energy dense) wouldn't be that bad- at 40 amps it would go up to 36-38km/h(with 20 inch wheel) which is all I need.

 

[ZeroEm]

by Peter Svancarek
LiFePO4

I am trying to have more battery as not to need to charge for every ride and only charge up to 80-90% and don't drain it to low 40-50% this will extend battery life. It's all how you look at it. Figure out how far is normal for you and how many watts you will need.
Could not tell what would be normal for me. mine varies from 0w - 1200w my battery stores 1800w (never tested it) 1200w was on 50+ mile trips.
peddle but have pas setup where you can make it as easy or hard as you need.

 

[John in CR]

I did a bit of fact finding about the Leaf motor, and it readily shows how Balmorhea has been piling on bad advice by the shovel full. First, according to Leaf's own test report, which was done at 48V, the peak efficiency of the motor tested was 90.7% . The motor used for that favorable report turned 602rpm on 48V for a Kv of 12.5rpm/v, which was like I suggested a 3t wind. Do they even offer such a motor for sale? That peak efficiency point occurred at 89% of no-load speed (549rpm), with power output of 900W, so it's going to take a very small wheel or a super aero form to achieve that.

On Ebikes.ca simulator only the 5t Leaf motor is represented. The highest efficiency that motor reaches is 87.5% and that's with a 72V pack. With a 48V pack the peak efficiency is only 86.5%, and with a normal type ebike the only way to get to peak efficiency without plenty of human power assist is by using an 18" or smaller diameter wheel, because at peak efficiency that winding is only capable of 575W of output. With the 18" wheel not only can peak efficiency be achieved, but it occurs at 90% of no load speed. Larger wheels with a 100kg all up load (rider and bike), present too much load for that little motor and performance and efficiency suffers accordingly.

FWIW my latest build uses a true high efficiency hubmotor with a chain drive gear reduction to drive the 27" OD tire so the motor "sees" an effective wheel diameter of 13" to make it great at climbing any mountain. On flat ground it achieves over 95% of no-load speed (87kph top speed...91kph no-load speed), and that's with 21" motorcycle tires and an all up load approaching 200kg. There's little doubt that this gearing makes it capable of reaching peak efficiency at any throttle position.

 

[Balmorhea]

First, according to Leaf's own test report, which was done at 48V, the peak efficiency of the motor tested was 90.7% . The motor used for that favorable report turned 602rpm on 48V for a Kv of 12.5rpm/v, which was like I suggested a 3t wind.

I think it's a 4T winding given that Leaf's sales rep told me:

1500w No-load at 48V for the 8 turn x 8 – about 293rpm
1500w No-load at 48V for the 9 turn x 7 – about 355rpm
1500w No-load at 48V for the 11 turn x 6 – about 418rpm

(Strand count is listed first, and turn count is second. Extrapolating the series suggests ~500 rpm for 5T and ~600 rpm for 4T.)

Note that 602 rpm with a 29" wheel (which is popular in the First World) implies a free speed (at 48V) of 52 mph. So that in turn implies a free speed at 24V of 26 mph.

Which means, in most of the First World, you'd probably be breaking the laws governing e-bikes at just 24V.

Last time I looked, 24V controllers and batteries were much less plentiful and less cost-effective than 36V or 48V versions. So the wise player in these situations will order a slower winding, to match a bicycle's competencies and prevailing legal limitations to the most economical and widely available equipment.

Those who lived in comparatively lawless undeveloped countries like Somalia etc. can of course do as they please, especially if they like to waste money and time looking for less widely supported equipment.

https://mytanfeet.com/about-cr/tips-for-driving-in-costa-rica/

Know that right of way is more like a suggestion in Costa Rica, many local drivers do not follow it. Same goes for traffic lights.

 

[John in CR]

First, according to Leaf's own test report, which was done at 48V, the peak efficiency of the motor tested was 90.7% . The motor used for that favorable report turned 602rpm on 48V for a Kv of 12.5rpm/v, which was like I suggested a 3t wind.

I think it's a 4T winding given that Leaf's sales rep told me:

1500w No-load at 48V for the 8 turn x 8 – about 293rpm
1500w No-load at 48V for the 9 turn x 7 – about 355rpm
1500w No-load at 48V for the 11 turn x 6 – about 418rpm

(Strand count is listed first, and turn count is second. Extrapolating the series suggests ~500 rpm for 5T and ~600 rpm for 4T.)

Note that 602 rpm with a 29" wheel (which is popular in the First World) implies a free speed (at 48V) of 52 mph. So that in turn implies a free speed at 24V of 26 mph.

Which means, in most of the First World, you'd probably be breaking the laws governing e-bikes at just 24V.

Last time I looked, 24V controllers and batteries were much less plentiful and less cost-effective than 36V or 48V versions. So the wise player in these situations will order a slower winding, to match a bicycle's competencies and prevailing legal limitations to the most economical and widely available equipment.

Those who lived in comparatively lawless undeveloped countries like Somalia etc. can of course do as they please, especially if they like to waste money and time looking for less widely supported equipment.

https://mytanfeet.com/about-cr/tips-for-driving-in-costa-rica/

Know that right of way is more like a suggestion in Costa Rica, many local drivers do not follow it. Same goes for traffic lights.

Ok, so the motor test report may be a 4 turn wind. The 3 turn would still be more efficient due to better copper fill, and would be the better choice in the overwhelming majority of the cases.

Regarding 29" wheels, only someone who hasn't learned better or who runs big power with a big motor pushing a light load and doesn't care about efficiency all that much as long as his motor doesn't burn up (like MadRhino), runs any direct drive HubMotor in large diameter wheels which includes 26" wheels too. The resulting gearing is simply too steep. The performance levels I run have absolutely no bearing on wheel size, though running proper wheel sizes is part of what permits me to overclock my systems to such extreme levels and the other part is pushing lighter all up loads than the motor was designed for. Since my new bike is built with off road in mind, it required lower gearing for steep mountain trails, and I wanted to reduce unsprung weight.

As far as the ridiculous so called "First World" comments are absurd. 29ers for street use is just another larcenous marketing ploy by the manufacturers to get you to buy more new equipment. As far as ebikes with direct drive hubbies go, it's exactly the wrong direction to take for multiple reasons.

"First World" what a joke...people getting in fights and worse over masks...people shooting each other in the street for virtually no reason...violent protests for months because criminals get crosswise with police and the protests continue despite justice being served to police who went too far.

Of course as usual you have to attempt to change the subject and get away from the hard facts. eg that peak efficiency with these motors occurs at almost 90% of no-load rpm, so on any kind of normal ebike they can't get to peak efficiency with anything larger than a 20" OD wheel without going down a hill or with a big tail wind. Without running fairly high current for the motor (like 40A battery side for a 5t and a 48V pack) the motor doesn't get much past the peak power point in the curve. Forget about very efficient operation with a big wheel even on flat roads, but where you get in real trouble is on hills, since with a 40A controller the load of just a 5% grade pushes the 5t down to the peak power point, and that's with a 26er. With a 29" wheel things get much worse, since just a 2% grade puts you down to the same point. Steeper on hills of sufficient length puts the motor at significant heat risk, especially as winding resistance goes up with temperature.

 

[Peter Svancarek]

I think it's a 4T winding given that Leaf's sales rep told me:

1500w No-load at 48V for the 8 turn x 8 – about 293rpm
1500w No-load at 48V for the 9 turn x 7 – about 355rpm
1500w No-load at 48V for the 11 turn x 6 – about 418rpm

(Strand count is listed first, and turn count is second. Extrapolating the series suggests ~500 rpm for 5T and ~600 rpm for 4T.)

Note that 602 rpm with a 29" wheel (which is popular in the First World) implies a free speed (at 48V) of 52 mph. So that in turn implies a free speed at 24V of 26 mph.

Which means, in most of the First World, you'd probably be breaking the laws governing e-bikes at just 24V.

Yeah... I'm well aware that there is limit 25km/h and 250W. First is easily measurable, second not so much. But it isn't probably that bad when this can be legal: https://www.jtsbicycle.com/bike2-chainless-hybrid-drive-e-bike-system-shipping-now/
I will be riding at legal max 25kmh. The controllers are programmable(according to videos). Offroad, I would like to have possibility to go up to 35km/h- that would pose also as reserve. I still didn't get answer about 14inch 1000W motor from Leaf company representative which could be overloaded up to 2000W.... (48V 40A input was suggested by representative)

 

[Peter Svancarek]

Regarding 29" wheels, only someone who hasn't learned better or who runs big power with a big motor pushing a light load and doesn't care about efficiency all that much as long as his motor doesn't burn up (like MadRhino), runs any direct drive HubMotor in large diameter wheels which includes 26" wheels too. The resulting gearing is simply too steep. The performance levels I run have absolutely no bearing on wheel size, though running proper wheel sizes is part of what permits me to overclock my systems to such extreme levels and the other part is pushing lighter all up loads than the motor was designed for. Since my new bike is built with off road in mind, it required lower gearing for steep mountain trails, and I wanted to reduce unsprung weight.

As far as the ridiculous so called "First World" comments are absurd. 29ers for street use is just another larcenous marketing ploy by the manufacturers to get you to buy more new equipment. As far as ebikes with direct drive hubbies go, it's exactly the wrong direction to take for multiple reasons.

"First World" what a joke...people getting in fights and worse over masks...people shooting each other in the street for virtually no reason...violent protests for months because criminals get crosswise with police and the protests continue despite justice being served to police who went too far.

Of course as usual you have to attempt to change the subject and get away from the hard facts. eg that peak efficiency with these motors occurs at almost 90% of no-load rpm, so on any kind of normal ebike they can't get to peak efficiency with anything larger than a 20" OD wheel without going down a hill or with a big tail wind. Without running fairly high current for the motor (like 40A battery side for a 5t and a 48V pack) the motor doesn't get much past the peak power point in the curve. Forget about very efficient operation with a big wheel even on flat roads, but where you get in real trouble is on hills, since with a 40A controller the load of just a 5% grade pushes the 5t down to the peak power point, and that's with a 26er. With a 29" wheel things get much worse, since just a 2% grade puts you down to the same point. Steeper on hills of sufficient length puts the motor at significant heat risk, especially as winding resistance goes up with temperature.

Thank you for sharing this. I have no experience with electric bicycles. It is why I ask
My feelings about wheel size are the same. Whats more, the smaller wheel the less resistance it provides during acceleration. With 20inch wheel I can out-accelerate at the same speed gear bicycles with bigger wheels. My normal bicycle has 26 inch wheels and I'm not able to accelerate on it as fast as on recumbent with 20 inch. Recently, I bought two 29inch wheel bicycles for my daghters- they wanted such big wheels and acceleration sucks on them, they feel really sluggish. No fun to drive them. when I compare those 15kg bicycles with my over 25kg heavy tricycle, the tricycle is like F1 out-accelerating them without effort

Efficiency without load? Then why they post graphs of efficiency with load? Is it fiction? For example 14inch/1000W hub wheel motor has stated efficiency of 90.5% at 48V, 21amps load https://www.leafbike.com/products/diy-bike-conversion-kit/14-inch-48v-52v-1000w-front-casted-electric-scooter-motor-kit-1191.html. I would use it as rear wheel of course.

LEAF has also this interesting hubmotor https://www.leafbike.com/products/diy-bike-conversion-kit/10-inch-48v-52v-800w-electric-scooter-kit-rear-wheel-1100.html I know it is 10 inch... I think, as rear wheel on suspension it should be still OK (12 inch wheel felt OK on gravel up to about 20mm diameter and field paths). I really don't plan rides in forests They rated the power at 1000W in tech. specifications. The efficiency is rated about 86% which I could live with if it is really at rated loads. Small diameter would suggest large thrust. Active motor diameter is smaller but the motor is probably much thicker... it has 2 times wider tire than 14inch/1000W motor .

What do you think about these options? I don't really need very high power motors... I ask for high torque and speeds up to about 35km/h. I have driven my tricycle at about 45km/h but I wouldn't try that very often, the tricycle was more lively during high power pedalling than I would prefer even in low traffic.

 

[John in CR]

Regarding 29" wheels, only someone who hasn't learned better or who runs big power with a big motor pushing a light load and doesn't care about efficiency all that much as long as his motor doesn't burn up (like MadRhino), runs any direct drive HubMotor in large diameter wheels which includes 26" wheels too. The resulting gearing is simply too steep. The performance levels I run have absolutely no bearing on wheel size, though running proper wheel sizes is part of what permits me to overclock my systems to such extreme levels and the other part is pushing lighter all up loads than the motor was designed for. Since my new bike is built with off road in mind, it required lower gearing for steep mountain trails, and I wanted to reduce unsprung weight.

As far as the ridiculous so called "First World" comments are absurd. 29ers for street use is just another larcenous marketing ploy by the manufacturers to get you to buy more new equipment. As far as ebikes with direct drive hubbies go, it's exactly the wrong direction to take for multiple reasons.

"First World" what a joke...people getting in fights and worse over masks...people shooting each other in the street for virtually no reason...violent protests for months because criminals get crosswise with police and the protests continue despite justice being served to police who went too far.

Of course as usual you have to attempt to change the subject and get away from the hard facts. eg that peak efficiency with these motors occurs at almost 90% of no-load rpm, so on any kind of normal ebike they can't get to peak efficiency with anything larger than a 20" OD wheel without going down a hill or with a big tail wind. Without running fairly high current for the motor (like 40A battery side for a 5t and a 48V pack) the motor doesn't get much past the peak power point in the curve. Forget about very efficient operation with a big wheel even on flat roads, but where you get in real trouble is on hills, since with a 40A controller the load of just a 5% grade pushes the 5t down to the peak power point, and that's with a 26er. With a 29" wheel things get much worse, since just a 2% grade puts you down to the same point. Steeper on hills of sufficient length puts the motor at significant heat risk, especially as winding resistance goes up with temperature.

Thank you for sharing this. I have no experience with electric bicycles. It is why I ask
My feelings about wheel size are the same. Whats more, the smaller wheel the less resistance it provides during acceleration. With 20inch wheel I can out-accelerate at the same speed gear bicycles with bigger wheels. My normal bicycle has 26 inch wheels and I'm not able to accelerate on it as fast as on recumbent with 20 inch. Recently, I bought two 29inch wheel bicycles for my daghters- they wanted such big wheels and acceleration sucks on them, they feel really sluggish. No fun to drive them. when I compare those 15kg bicycles with my over 25kg heavy tricycle, the tricycle is like F1 out-accelerating them without effort

Efficiency without load? Then why they post graphs of efficiency with load? Is it fiction? For example 14inch/1000W hub wheel motor has stated efficiency of 90.5% at 48V, 21amps load https://www.leafbike.com/products/diy-bike-conversion-kit/14-inch-48v-52v-1000w-front-casted-electric-scooter-motor-kit-1191.html. I would use it as rear wheel of course.

LEAF has also this interesting hubmotor https://www.leafbike.com/products/diy-bike-conversion-kit/10-inch-48v-52v-800w-electric-scooter-kit-rear-wheel-1100.html I know it is 10 inch... I think, as rear wheel on suspension it should be still OK (12 inch wheel felt OK on gravel up to about 20mm diameter and field paths). I really don't plan rides in forests They rated the power at 1000W in tech. specifications. The efficiency is rated about 86% which I could live with if it is really at rated loads. Small diameter would suggest large thrust. Active motor diameter is smaller but the motor is probably much thicker... it has 2 times wider tire than 14inch/1000W motor .

What do you think about these options? I don't really need very high power motors... I ask for high torque and speeds up to about 35km/h. I have driven my tricycle at about 45km/h but I wouldn't try that very often, the tricycle was more lively during high power pedalling than I would prefer even in low traffic.

Peter, I'm a unclear what you mean in comparisons of your trike to your daughters' bikes. If you're talking about human power only, then it's just a matter of gearing to make the same force where the tire meets the road. With a hubmotor the only way to change gearing is with wheel size, so yes a smaller wheel gives you more thrust. If the bikes and your trike are all electric, then you're seeing first hand the performance advantage of a hubmotor in a smaller wheel, which will become even more important in hilly terrain, and you will also get more range with the same battery capacity while traveling at the same speed.

Be careful about motor selection on that website, as the two you linked were not the high efficiency motor discussed in this thread. While those might work fine for you if you travel only flat terrain, the roads and pathways would need to be almost perfectly smooth for such a small wheel to result in a comfortable ride.

Regarding no-load speed, that is the speed the motor can reach at a given voltage with the wheel off the ground, my point is that for a very efficient ebike, on flat ground the bike should be able to achieve a high percentage of that no-load speed, say 85% or higher, and the higher the better especially if you travel in hilly terrain. Earlier in the thread Balmorhea suggested that achieving 75%-80% of no-load speed was good, but I maintain that would be very bad, because the ebike could never reach peak efficiency without going downhill and efficiency would be horrible on hills. That's why there are multitudes of burned up hubmotors running 26" or larger wheels here on the forum, but I challenge you to find a single one overheated to failure in a 20" wheel. While everyone from Texas thinks bigger is better, that's simply not the case, and if Balmorhea thinks a 20" wheel can't be used in a First World country, let's see him say so about Miles' engineering art electric Moulton that runs 20" skinny wheels. Sure big wheels ride smoother on bad terrain, but on ebikes they take up valuable battery space unless you extend the wheelbase significantly.

 

[Peter Svancarek]

Peter, I'm a unclear what you mean in comparisons of your trike to your daughters' bikes. If you're talking about human power only, then it's just a matter of gearing to make the same force where the tire meets the road. With a hubmotor the only way to change gearing is with wheel size, so yes a smaller wheel gives you more thrust. If the bikes and your trike are all electric, then you're seeing first hand the performance advantage of a hubmotor in a smaller wheel, which will become even more important in hilly terrain, and you will also get more range with the same battery capacity while traveling at the same speed.

Be careful about motor selection on that website, as the two you linked were not the high efficiency motor discussed in this thread. While those might work fine for you if you travel only flat terrain, the roads and pathways would need to be almost perfectly smooth for such a small wheel to result in a comfortable ride.

Regarding no-load speed, that is the speed the motor can reach at a given voltage with the wheel off the ground, my point is that for a very efficient ebike, on flat ground the bike should be able to achieve a high percentage of that no-load speed, say 85% or higher, and the higher the better especially if you travel in hilly terrain. Earlier in the thread Balmorhea suggested that achieving 75%-80% of no-load speed was good, but I maintain that would be very bad, because the ebike could never reach peak efficiency without going downhill and efficiency would be horrible on hills. That's why there are multitudes of burned up hubmotors running 26" or larger wheels here on the forum, but I challenge you to find a single one overheated to failure in a 20" wheel. While everyone from Texas thinks bigger is better, that's simply not the case, and if Balmorhea thinks a 20" wheel can't be used in a First World country, let's see him say so about Miles' engineering art electric Moulton that runs 20" skinny wheels. Sure big wheels ride smoother on bad terrain, but on ebikes they take up valuable battery space unless you extend the wheelbase significantly.

Hello
Are you aware of term "Gear inches" or "Gear meters" ? I meant there, that I can set (nearly) the same values of gear meters and therefore I can pedal with close to the same cadence and ridding at the same speed on bicycle with 29inch wheel and 20 inch wheel bicycle. So when I compare these two at the same gear/meters the 29inch wheel bicycle feels sluggish, accelerating at much slower rate than 20inch wheel bicycle. And mind you, the pedalling on classic bicycle is a bit easier than on recumbent for me (still) so I know that smaller wheels are better from real experience. The ride is smoother on bigger wheels- yes. But only on really bad road. And even if I had large wheels on recumbent it wouldn't be much better because I need either to ram the hole on road or to steer away from it(unlike of normal bicycle where I usually just jump over it )
On all recumbents I build I had rear 20inch and front 16inch wheels. And, on wooden experimental for steering geometry experiments I had only 12 inch wheels. There were no problems with that.

That 10 inch hubwheel has stated efficiency of 86% at 48/52V at 20A... yes, it is lower efficiency motor.

But this 14 inch hubwheel has stated efficiency of 90.6% at 48/52V at 21A according to the website https://www.leafbike.com/u_file/images/13_06_18/f415a5c455.jpg. Do they provide false data here? at the highest efficiency it has 14.4Nm which with 14 inch wheel translates to 81N thrust. That should be able to propel the 130kg mass up to about 6% hill. The representative suggested torques: If use 26A controller, max about 30N.m, If use 40A controller, max about 40N.m that would be away from efficient currents for this motor. But these torques would be needed only occasionally.

Do you think, I would be better off not to have hubmotor, but to connect the motor to wheel by chain at ratio I need? Mechanically it would be more complicated... and probably less efficient.

With regards Peter

Edit: I got answer fro LEAF. They are getting more and more irritated Well, what to do...
Below is our 5T 1500w motor performance data.
46 pcs 35 Height magnet and 35 height winding rotor.
https://www.leafbike.com/u_file/images/15_01_05/0a32577ead.jpg

Below is our 4T 1000w performance data.
It's the fastest.It works with max 26A controller,if works with 40A will be stronger, if use 5T will stronger.
46 pcs 30 height magnet.
https://www.leafbike.com/u_file/images/13_06_18/f415a5c455.jpg

 

[John in CR]

Do they provide false data here? at the highest efficiency it has 14.4Nm which with 14 inch wheel translates to 81N thrust.

Personally I would always opt for the fastest version of more powerful motor, in this case the 1500W motor but the 4 turn (not the 5 turn which he was incorrect about since that test report is for the 4 turn). I would do that even if I had to put the motor in the small size wheel myself. From what I can tell the weight difference is only 1 kilo, but the more powerful motor in a small wheel avoids stress much better.

 

[thundercamel]

What about 1000W hubmotor in 14 inch wheel? That engine is smaller and lighter. I tried to approximate the motor characteristics and fill them into simulator. It told me that that motor should climb 15% hill at speeds about 25km/h which is plenty for me.

The Leaf 1000w is a little skinnier, little lighter. 30mm stator vs. 35mm for the 1500w. I don't think the diameter is any different though, and would probably need at least a 20" wheel. I'm surprised you're willing to go with such a small diameter, which must be rough over the bumps at speed. Even Golden Motor MagicPie only goes down to 18".

https://www.leafbike.com/products/e-bike-hub-motor/14-inch-48v-52v-1000w-front-casted-hub-motor-electric-bike-wheel-1157.html The motor must have smaller diameter.

Oh wow, I didn't realize Leaf offered motors for tires that small. I was thinking only about the 1500w and 1000w motors for spoked wheels that most people use.

 

[2old]

How about Real World? There are multitudes of 26" steel MTB's like my late 80's Diamondback Axis) which have excellent handling characteristics. I wouldn't consider a bike with smaller wheels since BMX doesn't translate well to the street (and anomalies like Moulton's aren't feasible). The YESCOM 1000w, 48V system, with 52V battery has been an excellent commuter for five years and ascends any terrain in socal with aplomb.

 

[Balmorhea]

29ers for street use is just another larcenous marketing ploy by the manufacturers to get you to buy more new equipment.

I think you mean 27.5". That in-between size is a solution in search of a problem, and unlike 29"/700c, the tires and rims do cost extra.

In places where people ride bicycles for transportation, not primarily for sport or recreation, they've always used the largest available wheels-- either 700c with fat tires (which we now call 29") or the older wheel size standard of 28 x 1-1/2". This gives the best ride quality and lowest rolling resistance for any given kind of tire. These bikes are almost immune to fashion, so they stick with what works best.

What they never do is ride on donut wheels, unless it's for folding bikes that are the only kind allowed on public transit.

Donut wheels for hub motors only make sense if the rider's purpose is to serve the motor's needs, rather than the other way around.

 

[Peter Svancarek]

How about Real World? There are multitudes of 26" steel MTB's like my late 80's Diamondback Axis) which have excellent handling characteristics. I wouldn't consider a bike with smaller wheels since BMX doesn't translate well to the street (and anomalies like Moulton's aren't feasible). The YESCOM 1000w, 48V system, with 52V battery has been an excellent commuter for five years and ascends any terrain in socal with aplomb.

Real world-
Recumbent bicycle (homebuild)- good handling, rear 20" front 16". Acceleration weaker than on tricycle- probably because the stability is not best bellow about 3km/h. Still I can out-accelerate bicycles with larger wheels I have at home. Full suspension. Driving though potholes is not advisable(but it happened a few times when I didn't notice them because the angle of seat made it hard to spot). Driving through loose gravel is a horror. I hate to stop on road lights with it. Starting up the hill from stop is hard... really hard. Steeper hills make it impossible.

Recumbent tricycle(homebuild)- very good handling and excellent stability. Excellent acceleration. I was nearly thrown from it a few times during hard turning, but tricycle didn't lift wheel, rear 20" front 16". Rear suspension only, but it is enough, big apple tires are enough on front wheels when the wheel gets less than 40 kg of load. Able to drive without hands(in straight line). Driving through loose gravel is without problems, steering without problems, rear wheel can slip and slip if pedalling too hard on easier gears. I made 180 turn on gravel too when I tried to steer on it. I pedalled too hard so rear wheel slipped- but it was sooo much fun. The loose gravel was flying around me Pure fun. Start and stop, without getting feet from pedals. If you are tired pedaling up the steep hill, simply press brakes and wait till you are bit rested, then simply pedal again. Without getting feet from pedals!

My old steel cross bicycle, all 26" wheels, good handling. No suspension. Feels sluggish in comparison to much heavier recumbents, especially trike. Driving through pot holes not advisable, jumping over them is preferable! Loose gravel is dangerous! I didn't try to do fancy things like never, still I nearly fell down a few times.

Daughters new bicycle all 29" wheels. Front suspension, 15kg(quite light). Handling feels very, very sluggish. Hard to turn, the steering battles against it. Driving through potholes is not advisable. Jumping over is preferable. Driving on gravel is as bad as on my old bicycle. Acceleration is worst I ever experienced on bicycle.

Adding electric motor would duplicate the result, possibly enhance acceleration on recumbents, especially on two-wheeled one.

 

[john61ct]

my latest build uses a true high efficiency hubmotor with a chain drive gear reduction to drive the 27" OD tire so the motor "sees" an effective wheel diameter of 13" to make it great at climbing any mountain.

Do you mean the (what was designed to be a) hub motor is mid-mounted?

Have you got a build thread you could link to?

 

[2old]

How about Real World? There are multitudes of 26" steel MTB's like my late 80's Diamondback Axis) which have excellent handling characteristics. I wouldn't consider a bike with smaller wheels since BMX doesn't translate well to the street (and anomalies like Moulton's aren't feasible). The YESCOM 1000w, 48V system, with 52V battery has been an excellent commuter for five years and ascends any terrain in socal with aplomb.

Real world-
Recumbent bicycle (homebuild)- good handling, rear 20" front 16". Acceleration weaker than on tricycle- probably because the stability is not best bellow about 3km/h. Still I can out-accelerate bicycles with larger wheels I have at home. Full suspension. Driving though potholes is not advisable(but it happened a few times when I didn't notice them because the angle of seat made it hard to spot). Driving through loose gravel is a horror. I hate to stop on road lights with it. Starting up the hill from stop is hard... really hard. Steeper hills make it impossible.

Recumbent tricycle(homebuild)- very good handling and excellent stability. Excellent acceleration. I was nearly thrown from it a few times during hard turning, but tricycle didn't lift wheel, rear 20" front 16". Rear suspension only, but it is enough, big apple tires are enough on front wheels when the wheel gets less than 40 kg of load. Able to drive without hands(in straight line). Driving through loose gravel is without problems, steering without problems, rear wheel can slip and slip if pedalling too hard on easier gears. I made 180 turn on gravel too when I tried to steer on it. I pedalled too hard so rear wheel slipped- but it was sooo much fun. The loose gravel was flying around me Pure fun. Start and stop, without getting feet from pedals. If you are tired pedaling up the steep hill, simply press brakes and wait till you are bit rested, then simply pedal again. Without getting feet from pedals!

My old steel cross bicycle, all 26" wheels, good handling. No suspension. Feels sluggish in comparison to much heavier recumbents, especially trike. Driving through pot holes not advisable, jumping over them is preferable! Loose gravel is dangerous! I didn't try to do fancy things like never, still I nearly fell down a few times.

Daughters new bicycle all 29" wheels. Front suspension, 15kg(quite light). Handling feels very, very sluggish. Hard to turn, the steering battles against it. Driving through potholes is not advisable. Jumping over is preferable. Driving on gravel is as bad as on my old bicycle. Acceleration is worst I ever experienced on bicycle.

Adding electric motor would duplicate the result, possibly enhance acceleration on recumbents, especially on two-wheeled one.

You're a lot braver than I am since I wouldn't ride a recumbent or trike in socal; too many SUV's with drivers that are distracted. Probably no safer on a 26" bike but it feels like I have better vision and visibility. May just be me though. I'm riding less on the road and more off road.

 

[John in CR]

my latest build uses a true high efficiency hubmotor with a chain drive gear reduction to drive the 27" OD tire so the motor "sees" an effective wheel diameter of 13" to make it great at climbing any mountain.

Do you mean the (what was designed to be a) hub motor is mid-mounted?

Have you got a build thread you could link to?

Yes a HubMonster mounted on the swingarm as close to the pivot as I could get it. https://endless-sphere.com/forums/viewtopic.php?f=28&t=108000 Currently not much in the way of pics. I'll remedy that while I have it apart to neat up and trim the non-essential steel, and paint it as well as fab a cover.