Leaf / leafmotor / leafbike high efficiency 1500w motor

[E-HP]

I'm planning an ebike conversion for my wife using a BMX frame. Actually, I'm planning on a dual purpose bike. I'm hoping to use the same cheap sine wave controller that I'm currently using on my bike, but modifying it to work on 14S (hopefully). I will be using a toque sensing PAS, if these adapters can work with one https://www.amazon.com/Truvativ-00-6415-027-000-American-To-Euro-Bmx-Adapter/dp/B000VT550K/?_encoding=UTF8&pd_rd_w=4u9mu&content-id=amzn1.sym.8cf3b8ef-6a74-45dc-9f0d-6409eb523603&pf_rd_p=8cf3b8ef-6a74-45dc-9f0d-6409eb523603&pf_rd_r=BNAEFTZ1CE64B8V41VS4&pd_rd_wg=u4eD2&pd_rd_r=e0d69fc5-f065-4a6b-a4b9-7ce405e28b93&ref_=pd_gw_ci_mcx_mi
I'll have a 14S Hailong pack under the downtube

I'll use a CA, so I can detune the bike for her use through the CA and soft start on the controller, and it will be a single speed drivetrain, hopefully geared for about 16 MPH at a comfortable cadence, if chainring clearance allows. Short travel suspension fork up front with disc brake, rim brakes out back, Thudbuster LT seatpost. Hookworms front and rear and big cushy seat.

It's alter ego will be a pit bike. For that I'd unlock the speed and 40A to 50A or so, and parallel 14S of 5Ah lipos for extra capacity for darting around, and higher current, while eliminating any voltage sag. It should be able to climb any hill. Probably swap out the cushy seat, LOL.

So I have a couple of questions about the 1500W BMX Leaf, the first just informational, and the second possibly affecting the build, if anyone knows:

• If the axle flats are cut to fit the 14mm rear BMX dropout, is the actual axle a larger diameter compared the the normal Leaf motor?
  If so, it seems like some other things would be affected (bearings, side covers, etc.).

• Seems like custom torque arms will be needed if the frame is aluminum. Is that a safe assumption?

https://www.leafbike.com/products/e-bike-hub-motor/bmx-20-inch-48v-52v-1500w-rear-hub-motor-electric-bike-wheel-1264.html?VariantsId=10397

Thanks in advance for anyone that knows about this version of the motor. :thumb:

 

[amberwolf]

I'm planning an ebike conversion for my wife using a BMX frame.
<snip>
So I have a couple of questions about the 1500W BMX Leaf,
<snip to move motor link here> https://www.leafbike.com/products/e-bike-hub-motor/bmx-20-inch-48v-52v-1500w-rear-hub-motor-electric-bike-wheel-1264.html?VariantsId=10397
<snip>
the first just informational, and the second possibly affecting the build, if anyone knows:
If the axle flats are cut to fit the 14mm rear BMX dropout, is the actual axle a larger diameter compared the the normal Leaf motor?

None of the BMX frames I've personally used have had anything other than regular 10mm dropouts. What specific BMX bike are you using?

The only thing I see specially different on this motor vs other rear motors is it is "Install: spacing of 110mm rear fork", meaning 110mm-wide dropouts vs 135mm of a typical bike frame (rear wheel), and that's typical of the BMX frames I've had, too (has enabled me to use front motors on the rear).

I think there is a mistake in either the pics/drawing or the text of the specs, though, becuase it says "Cable location: shaft end, LEFT" yet the cable seems to come out of what I am guessing is the freewheel side (which would be on the right). I can't actually tell from the images or drawings if there is a threaded freewheel mount, however. That could just be a disc-brake-rotor mount.

If there's no freewheel mount, then you could just use a plain old front motor in the back of a BMX without buying anything special (because that's essentially all this would be, really). Might require spacer washers between dropouts and axle shoulders if the motor is narrower than the frame.

Seems like custom torque arms will be needed if the frame is aluminum. Is that a safe assumption?

I would recommend torque arms on any hubmotor on any frame that doesn't have clamping dropouts to pinch-hold the axle flats.

As for custom...that will depend on your frame's design, if typically available ones will fit or not. I don't see anything in the specs available on that page that shows they wouldn't fit the motor itself.

 

[Chalo]

• If the axle flats are cut to fit the 14mm rear BMX dropout, is the actual axle a larger diameter compared the the normal Leaf motor?

• 
  
  To judge by the videos (in which you can see the axle nuts rather than only the plastic nut covers), the axle seems to be the same 14x10mm size as the front and 7sp freewheel rear motors.
  
  Hypothetically, that would give you the option of making a torque arm that locates the axle in a vertical orientation, perpendicular to the slot, rather than horizontal with the flats parallel to the slot.

 

[E-HP]

• If the axle flats are cut to fit the 14mm rear BMX dropout, is the actual axle a larger diameter compared the the normal Leaf motor?

• 
  
  To judge by the videos (in which you can see the axle nuts rather than only the plastic nut covers), the axle seems to be the same 14x10mm size as the front and 7sp freewheel rear motors.
  
  Hypothetically, that would give you the option of making a torque arm that locates the axle in a vertical orientation, perpendicular to the slot, rather than horizontal with the flats parallel to the slot.

• 
  
  It would be nice if they used a BMX frame for the video, instead of some random frame for a larger bike/wheel. The problem I see, if the video is accurate, is that the axle is too short, even without torque arms, to get the axle nut to fully engage, and that's on a frame with pretty narrow dropouts, from what I see. Plus, notice that the nuts are only hand tightened https://youtu.be/IuWft5737yQ?t=51
  
  Everything I've read online says the BMX rear axle standard is 14mm. You can see in this example that I'm considering.
  
  
  
  
  I found this video of something similar to what I'm thinking of, but using the 1000W Leaf BMX motor:
  https://www.youtube.com/watch?v=b2lOQ7KGgd8&t=5s

 

[Chalo]

Everything I've read online says the BMX rear axle standard is 14mm.

All BMX bikes used 3/8" (9.5mm) axles until the 1990s, when 14mm axles were introduced. Since then, both standards have coexisted, with most high quality, current production bikes settling on 14mm rear and 3/8" front axles.

 

[E-HP]

Everything I've read online says the BMX rear axle standard is 14mm.

All BMX bikes used 3/8" (9.5mm) axles until the 1990s, when 14mm axles were introduced. Since then, both standards have coexisted, with most high quality, current production bikes settling on 14mm rear and 3/8" front axles.

Thanks! So it seems like the BMX Leaf may be designed for old school BMX bikes, and I might need to get creative using a newer frame. If so, I could either make some steel 10mm spaced dropouts with the slot parallel the existing, or rotate the axle so the 14mm dimension works with the existing slot, and add a normal torque arm to keep the axle from rotating. Maybe I'll start looking at early 90's steel BMX frames, but there are more suspension fork options for the newer frames with 1 1/8" headsets.

 

[amberwolf]

The problem I see, if the video is accurate, is that the axle is too short, even without torque arms, to get the axle nut to fully engage, and that's on a frame with pretty narrow dropouts, from what I see.

Unfortunatley their drawing doesn't actually specify axle length (or hardly any other dimensions),
https://ueeshop.ly200-cdn.com/u_file/UPAR/UPAR801/images/18_09_18/8b61a9212b.jpg

But based on what little they do show, I would guess that the actdual shoulder to shoulder axle distance is 100mm, then they're using washers to make it 107mm (per the drawing's lines) or 110mm per the "spec" on the sale page.

A guesstimate of the distance from the shoulder to the axle cap end is about 45-50mm, as it seems about the same distance as that from the centerline to the shoulder.

If the axle caps are the same size as the ones I've had on ohter motors, they probably stick out from the axle ends about 10-15mm (not counting the part that's actually overlapping the axle). So if we subtract about 15mm, that leaves about 35mm usable axle length on each side. If the dropouts are 5mm thick, and the nuts are 10-12mm thick, then there's 35mm - 17mm = 18mm left for washers and torque arms, which ought to be enough. If it's only 45mm, then that's just 13mm left...whcih should still be enough.

But that's a lot of guesswork.


If you end up getting one of these, please post up the actual dimensions of it--I've got an odd trike here that Cvin would like to add a motor to for someone, and this motor is the only presently-available one that might fit it...maybe.

Everything I've read online says the BMX rear axle standard is 14mm. You can see in this example that I'm considering.
https://images.craigslist.org/00l0l_ggBBlB84nMSz_0CI0hD_1200x900.jpg

Interesting. I guess I've been "lucky" in that everything I've run across has happened to be the old "10mm" version (mostly I used to pickup the used BMXes to their relatively strong small wheels on my trailers, but now I build them with bigger wheels and a suspended-deck frame so it's been a while).

 

[Cowardlyduck]

I'm not going to find it, but if you search back in this thread around 2016/2017 you should find when I ordered my Leaf for my Stealth Fighter with a custom made axle with wider shoulders to fit it.
Didn't cost any extra from memory, just ask them and they may make it for you like that.

Cheers

 

[E-HP]

I'm not going to find it, but if you search back in this thread around 2016/2017 you should find when I ordered my Leaf for my Stealth Fighter with a custom made axle with wider shoulders to fit it.
Didn't cost any extra from memory, just ask them and they may make it for you like that.

Cheers

Thanks for the tip. I think I recall reading about requesting a longer axle too somewhere either on this thread, or another, I can't recall. Of course I forgot about that when I ordered mine. I won't forget next time. :wink:

 

[AdR]

Anyone has any issues running the leaf 1500W in a 20 inch rim.

 

[Chalo]

Anyone has any issues running the leaf 1500W in a 20 inch rim.

You'll need to lace the wheel radially (no spoke crossings), but there's no reason not to use a 20" wheel. Figure out what to speed you want and whether you will have enough power to go that fast, and then tell them what speed/wheel size or RPM you want at the time you order. They'll give you a winding count that works to do that.

 

[neptronix]

Anyone has any issues running the leaf 1500W in a 20 inch rim.

Shouldn't be any... maybe too much torque..

 

[AdR]

Thx@Chalo/Neptronix. Bought the motor in a 24 inch wheel when I thought I needed to go 40mph .After using the grim motor sim, a 20 inch wheel showed better performance/efficiency at 30mph which is a better speed for me. with tuning on a phase runner controller the kva is about 11.65 with efficiency about 87% at 30mph.

 

[wilsgrant]

Hey Gang,

I recently purchased the 1500w nominal leafmotor kit listed here: https://www.leafbike.com/products/beach-snow-fat-bike-kit/20-inch-48v-52v-1500w-rear-hub-motor-beach-snow-fat-tire-bike-conversion-kit-1233.html?VariantsId=10018

The kit arrived with a controller labeled 45a. The listing states 40a. I would have been happy with either of these power levels, but instead after installing the kit I found that the controller is limiting itself to 1500 watts (less than 30 amps).

I am running on 52v, simple math shows I should be getting at least 2340 watts. So, I am only getting 64% of the expected performance. Unfortunately this makes a pretty big difference going up hills. I would not have gone with a DD hub motor with only 1500w peak of performance.

The display settings for max amps and watts seem to make no difference. I made sure it was set to 2500w and 45a but I still only get 1500w. Then to test to see if these settings even do anything I set them to 300w and sure enough the controller still peaks at almost exactly 1500w.

Here is where it gets weird. I contacted Leafmotor support and they seem to be trying to gaslight me by saying 1500w is normal for their 45a controller. Has anyone else had this experience with their kits? Would really appreciate any suggestions. Thank you very much for reading.

 

[Rix]

Hey Gang,

I recently purchased the 1500w leafmotor kit listed here: https://www.leafbike.com/products/beach-snow-fat-bike-kit/20-inch-48v-52v-1500w-rear-hub-motor-beach-snow-fat-tire-bike-conversion-kit-1233.html?VariantsId=10018

The kit arrived with a controller labeled 45a. The listing states 40a. I would have been happy with either of these power levels, but instead after installing the kit I found that the controller is limiting itself to 1500 watts (less than 30 amps).

I am running on 52v, simple math shows I should be getting at least 2340 watts. So, I am only getting 64% of the expected performance. Unfortunately this makes a pretty big difference going up hills. I would not have gone with a DD hub motor with only 1500w peak of performance.

The display settings for max amps and watts seem to make no difference. I made sure it was set to 2500w and 45a but I still only get 1500w. Then to test to see if these settings even do anything I set them to 300w and sure enough the controller still peaks at almost exactly 1500w.

Here is where it gets weird. I contacted Leafmotor support and they seem to be trying to gaslight me by saying 1500w is normal for their 45a controller. Has anyone else had this experience with their kits? Would really appreciate any suggestions. Thank you very much for reading.

Yah, even the link you provided to the website indicates 1500w for controller out put. I am not familiar at all with the system's computer monitor that's included, does it have a menu you can access to search/adjust settings? It may not and may be dependent on external support (lap top with app) to change settings. Maybe its limiting output based on measured watts? So 30amps with a 52 volt system. A 36 volt system would need 40-45 amps to achieve 1500w output. I just don't know, but these are things to consider.

 

[wilsgrant]

1500w is the nominal power rating. As you can see on the listing, it shows a 40 amp controller which would imply at least 2,000 watts peak at 52v. Just like how a "1000w" BBSHD does not peak at 1000w with it's stock 30 amp controller, it peaks at over 1700w. The 1000w rating is nominal power.

Per my earlier post I tried adjusting the setting in the display but it seems to have no effect on the controller. It doesn't matter if the display is set to 100w or 2000w, the controller ignores the setting and limits output to 1500w.

So far I am very disappointed in this kit, I ended up paying over $650 for it with the color display upgrade after shipping. Leafbike's response so far has been abysmal. They shouldn't be advertising 40a in the listing and providing 30a limited controllers, that is false advertising, right? And honestly who would want to run such a heavy DD Hub at only 30a 52v? At that point you might as well use a bafang geared hub motor...

Still hoping someone at Leafbike decides to help with this... But so far via email all I've gotten is gaslighting sadly. If anyone else has had this experience or has any ideas I'm all ears. If you are having better results with a non leafbike kit controller I'd also be interested in hearing your experience. Thanks again

 

[neptronix]

I have never touched their controllers and wouldn't suggest anyone do.. the motor needs a 60-80 amp controller if we're talking about the default 4T in a 26" wheel - 60A is where the fun starts.

1500w is the nominal rating of the motor ( realistically more like 1900W per our testing ), not the output of the controller necessarily and without a watt meter confirming the amps/volts then we don't know if the controller is outputting 40 amps or not..

..but i can tell you that 40A is not enough amperage to get the 4T moving in an acceptable manner and it's a shame that they didn't at least sell you a 60A controller with that wind.

 

[Rix]

I have never touched their controllers and wouldn't suggest anyone do.. the motor needs a 60-80 amp controller if we're talking about the default 4T in a 26" wheel - 60A is where the fun starts.

1500w is the nominal rating of the motor ( realistically more like 1900W per our testing ), not the output of the controller necessarily and without a watt meter confirming the amps/volts then we don't know if the controller is outputting 40 amps or not..

..but i can tell you that 40A is not enough amperage to get the 4T moving in an acceptable manner and it's a shame that they didn't at least sell you a 60A controller with that wind.

Couldn't agree with you more.

 

[wilsgrant]

Agreed, providing a 29 amp limited controller with this motor is a joke. I figured 40a-45a would be just enough in a 20 inch wheel for my purposes, but what I was shipped is limited to 29 amps (as confirmed by both displays they shipped (standard B&W one and the color upgraded one I paid for) real-time watts and amps readings, and my butt dyno climbing mild hills) which is not what I ordered and is obviously not enough to enjoy this motor.

Question: If you were in this situation, and Leafbike refused to help, would you consider a Paypal dispute? It seems this could fall under buyer protection of receiving an item that is different than the description.

Can anyone suggest a programable controller kit to use with this motor other than the phaserunner/frankenrunner?

 

[electric_nz]

I measured the 18 FET stock controller at 40A on my watt meter, I’ve shunt modded it to 50A with no worries at all, thinking of going a bit higher to 60A as it doesn’t get warm.

The only issue I’ve had is the top speed limit needed to be changed to 100 from the stock 40kph and for some reason it doesn’t retain PAS settings or odometer when powered off.

I’m looking at trying an eBay 80A controller from the other thread as I don’t use regen.

 

[wilsgrant]

Yeah I think what happened here is they switched from the 40a controller you have that actually outputs 40a to a new "45a" controller that has programming limiting it to 29a. They seem to be clueless about it.

What is the 80a ebay controller that is compatible you mentioned?

 

[electric_nz]

https://www.endless-sphere.com/forums/viewtopic.php?f=3&t=117429&start=25

 

[E-HP]

https://www.endless-sphere.com/forums/viewtopic.php?f=3&t=117429&start=25

I just did a mild shunt mod, that got it from 60A to 67A so far, so shooting for the rated 80A, then maybe beyond.
https://endless-sphere.com/forums/viewtopic.php?f=6&t=97945&start=250#p1735344

 

[Dunlop]

So does anyone know how many turns motor is the default "Off-the-shelf motor"?? I thought I read 5T was standard, and other turn counts needed to be requested, but I can't find it now...
Thanks,
Keith

 

[neptronix]

Re controller suggestions..
I have a fleet of trusty old infineons and an unused phaserunner.. i have not kept up with controller trends at all.
I am not sure who sells infineon clones anymore, and there's better controllers on the market.

Check our motors and controllers section to see what's hot lately, there's a lot of programmable controllers out there that are well known by other people on this forum.