26" BMX DK Legend Build

This is the kit I bought, it’s marketed as 60v

www.leafbike.com

BMX 26 inch 60V 2000W rear hub motor - electric bike conversion kit

Convert your 26 inch original bike to be ebike with leaf 26 inch 60V 2000W rear bmx hub motor electric bike conversion kit rear drive.
www.leafbike.com www.leafbike.com

I also confirmed with Leafbike that the kit would work with the battery they sell. This is what I bought

www.leafbike.com

60V 30AH electric bike battery - triangle battery

The triangle lithium battery powered ebike with leaf 60V 30AH electric bike battery.
www.leafbike.com www.leafbike.com

I’ll see how I can check the voltage today.
 
The most common causes of what you appear to be seeing:

--wrong phase hall combination. This would be eliminated by disconnecting the hall sensors, if the controller is sensorless capable.

--poor connection (excessive resistance) between controller and motor phase wires. Only one of them has to be a problem to cause this.

--damaged FETs in the controller in one phase, not actually blown but not operating as they should; sometimes it's not the FETs but a gate driver instead.

--Controller current limit settings, if any--if the limit is too low, the motor would stall under any load higher than that limit.

Unlikely to be a battery or battery connectoin issue, if there's no "brownout" under load and the controller is sold to work with this specific battery.


If it's an FOC controller (unlikely) then it won't correctly operate the motor until it has been fully setup and "tuned" to the specific motor, etc. That usually is done via serial cable and PC program, or bluetooth and a phone app...if they don't supply those with it then it's unlikley to be an FOC controller as those would be required to be done by the end user with their specific system parts (unless the seller provides a completely configured kit including battery/etc, which is very rare).
 
After much back and forth troubleshooting with Leafbike they have sent me three items free of charge. The new parts are due to me be here in a few days. I'll do some swapping and hopefully fix the issue.

A replacement 18 MOSFET 60v 40 amp controller (same as what I currently have)
A new 24 MOSFET 60v 55 amp controller
A new LCD screen (LCD-003 on their website)
www.leafbike.com

60V 55A fat snow electric bike motor controller

The leaf 60V 55A bike motor controller is so easy to drive your electric bicycle.
www.leafbike.com www.leafbike.com
 
BallHarder said:
After much back and forth troubleshooting with Leafbike they have sent me three items free of charge. The new parts are due to me be here in a few days. I'll do some swapping and hopefully fix the issue.

A replacement 18 MOSFET 60v 40 amp controller (same as what I currently have)
A new 24 MOSFET 60v 55 amp controller
A new LCD screen (LCD-003 on their website)
www.leafbike.com

60V 55A fat snow electric bike motor controller

The leaf 60V 55A bike motor controller is so easy to drive your electric bicycle.
www.leafbike.com www.leafbike.com
Click to expand...
Hi Ball,

Seems like a big effort now but builds are dynamic pieces of art or junk and how you adapt is the key to getting what you want or get. Sometimes you get results that were intentional other times you get something that will never get finished.

Keep up the diligence and good work, well done so far.

Cryingmadman

“Ideas are easy execution is a bitch”

Marie Antoinette
 
I am happy to report that switching to the silver 55amp controller fixed the issue! This thing absolutely rips.

I only took it out for a quick test ride but it put a huge smile on my face. Lots of torque. I need better brakes.

Thanks for everyone’s help. I’ll post a pic when it’s all tidy but for now here she is.

IMG_4902.jpeg
 
Hummina Shadeeba said:
Two-way throttle is nice w a hub n easy set up. Good brake.
Click to expand...
What on earth is a two-way throttle? Reverse or regenerate? Why haven't I heard about this before? 🤔

I can use this to accomplish some really creative stuff. Me gusta, me gusta.
 
AdR said:
@Hummina Shadeeba -where can I buy this 2way throttle?
Click to expand...

Wuxing Newest Half Twist Throttle,2 Way Functions,Rotating Up Is Braking,Rotating Down Is Speed Up,Factory Sells Directly - Buy Electric Bike Throttle,Hand Throttle,Electric Scooter Throttle Product on Alibaba.com

Wuxing Newest Half Twist Throttle,2 Way Functions,Rotating Up Is Braking,Rotating Down Is Speed Up,Factory Sells Directly - Buy Electric Bike Throttle,Hand Throttle,Electric Scooter Throttle Product on Alibaba.com
x.alibaba.com x.alibaba.com

They will sell even one or two I think. If they won’t I probably have an extra beyond the extra I have for backup I’d sell but ask them first.

Spintend also sell a two-way wheel

Assuming ur esc is capable. Vesc is.
 
I was thinking of suspension, at least on the front. It all depends on how fast you plan to go. In my experience if you want to travel at road speed you're in motorcycle territory, and you'll want the things that a motorbike has, like suspension. Coming off a bike at 30+mph is a life altering event.
 
gromike said:
I was thinking of suspension, at least on the front. It all depends on how fast you plan to go. In my experience if you want to travel at road speed you're in motorcycle territory, and you'll want the things that a motorbike has, like suspension. Coming off a bike at 30+mph is a life altering event.
Click to expand...
When I was considering the BMX route, I found very few frames that supported disc brakes or could fit a suspension fork. I think there were maybe 2; 24” models.
The bike was going to be for my wife. I switched my plan toward certain model years of the Specialized 24” Hotrock kids bike. Has disc brake posts, super low top tube, and enough room for a shark pack under the downtube without interfering with suspension travel (I was considering going with 20” rims for better climbing, which makes clearance even less of a problem). With higher rise bars, it would look a little BMX-like.:p Top tube distance similar to a large BMX frame, but with longer chain stays.
If it was for me, I might still consider a BMX since I already have an ebike, but for her, stopping is important and there are parts of the bike path that are fairly bumpy due to tree roots under the asphalt.
I still haven’t pulled the trigger on building it, since she only shows lukewarm interest. That means I’ll need to look for a decent paint color in case it turns into mostly my bike.
 
I'm done with this hub motor/wheel. It's not going to work for my bike and I'm tired of trying to force it.

I got it to work for a little bit with the upgraded controller but even with the torque arm it doesn't feel stable or safe since the axle is much too small for the frame.

I'm now on the hunt for a mid drive motor that will be compatible with my 60v battery if anyone has any suggestions. I reached out to Luna cycle and they said only up to 52v for the BBS02 and BBSHD motors.

Leafbike truly screwed me with their deceptive marketing of a "BMX" kit. Caveat emptor I suppose.
 
Sounds like you still have some other fabrication options to explore, some which don't even involve welding.

If that bike doesn't have a standard english thread bottom bracket then it's likely to never accept a mid drive without fabrication.

Nobody really converts BMX bikes because they aren't designed for high speed at all. No gears, wimpy brakes, wimpy fork interface, uses it's own bike standards, BMX is a pain in the ass.

Consider getting a mountain bike with 26" wheels ( hub motors like smaller wheels )
 
Watching your TA fabricating progress on the TA pictorial page I think it was, it looked like you were on the right track. Those clamping TAs should be holding that hubmotor very firm.

What exactly is happening? Dropout slot too sloppy (even clamping)? Loose or unsecure mounting to frame? Should have asked there, but did you make them out of aluminum? (Steel would be better, but harder to work with)(however, not with the right tools)

Sure , that big motor at 60V in a BMX frame is going to be a handfull, but thought that was the effect was what you were after?
 
99t4 said:
Watching your TA fabricating progress on the TA pictorial page I think it was, it looked like you were on the right track. Those clamping TAs should be holding that hubmotor very firm.

What exactly is happening? Dropout slot too sloppy (even clamping)? Loose or unsecure mounting to frame? Should have asked there, but did you make them out of aluminum? (Steel would be better, but harder to work with)(however, not with the right tools)

Sure , that big motor at 60V in a BMX frame is going to be a handfull, but thought that was the effect was what you were after?
Click to expand...
It worked for a while. Now the wheel only twitches when you turn the throttle. I'm not interested in getting stranded or having the wheel come apart. I have had enough concussions.

I took it back to stock and I guess I'll try to sell the Leafbike junk on Offer Up. What a waste of money and time.
 
Hummina Shadeeba said:
What was wrong? I’ve used those torque arms in two other bikes and work no problem
Click to expand...
I don't know. It worked for a little while but eventually the wheel only twitched when you turned the throttle. Not worth getting stranded (or worse). I'll try to sell the Leafbike junk on Offerup for half what I paid.
 
Hummina Shadeeba said:
leaf motors are generally well regarded. Maybe it’s a simple fix you’re missing
Click to expand...
Might be. I’ve wasted enough time and money. They marketed the kit as a 26” BMX Kit even though the drop outs don’t match.

Then, they suggested I just fabricate a part. If I wanted to fabricate stuff I wouldn’t have bought the kit.

Then, the controller they sent wouldn’t work with my battery and motor so they sent a new, larger controller.

That worked for a little while and now it doesn’t. I’m cutting my losses and I’ll try to sell this junk.

It’ll be hard to sell because it is 120mm wide and a 26” rim which basically ONLY fits a BMX bike (except for the drop outs of course).
 
BallHarder said:
Might be. I’ve wasted enough time and money. They marketed the kit as a 26” BMX Kit even though the drop outs don’t match.
[...]
It’ll be hard to sell because it is 120mm wide and a 26” rim which basically ONLY fits a BMX bike (except for the drop outs of course).
Click to expand...
BMX bikes had 3/8" axles for almost all their history. Just because yours is impaired by fashion doesn't make your motor wrong.
 
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