Bafang M620 Ultra motor broken? Low torque problem. Best retailer for US?

[MAF1008]

My Rize RX 2021/2022, which has the 1000W 52V Bafang M620 motor, suddenly lost most of its torque. It still has some power, but on flat ground seems to go no faster than around 20mph, and it no longer has enough torque to go up steep hills. The amount of electricity that goes in, per the screen, varies depending on the amount of torque needed- it can send more current when going downhill at fast speeds, while it sends very little when going uphill even at a low speed. Before this problem started, it could output at 1500W.

I have two batteries, both charged to 100%, and their health is and was fine. It doesn't matter if I use the throttle or not, this is not a sensor issue. I took my RX to a local e-bike specialty store, and they said after examining it and conferring with Rize, it needs a new motor. But they didn't suggest a specific retailer to buy the motor from. Some of the options I found online seem sketchy, and they're all expensive.

Anyone have a specific recommendation for an online retailer selling a replacement Bafang M620 motor for my Rize RX to the United States? Yes, I've googled this and found potential sources, but I was hoping someone might have had experience with this. The best place I've found online seems to be California Ebike, which has it for $824 with free shipping and no tax. Any better retailers?

I'd also hate to buy a motor, and pay to have my local e-bike store replace it, and then that's not even the problem. Has anyone else had a similar problem, whether for a Bafang M620 or any similar mid-drive? I assumed it wasn't the controller because I think the controller would either work or not work at all. It's also not a speed limit issue, because the lack of power is a problem even when starting from a stop, and when trying to go up a hill even at low speed.

 

[JRA]

Bafang Ultra M620 G510 barebone motor-greenbikekit.com BBS, ebike batteries, Bafang M620, Bafang M600, Bafang M500, Bafang M510, KT controller with display-GreenBikeKit.com

Bafang Ultra M620 G510 bare bone motor for replacement;

www.greenbikekit.com

This is what I used when I drowned my original motor. The UART version is preferable because it can be tuned easily via the available programming. IIRC CA eabike only offers the CanBus version. Also you will want the 52v as well. They shipped fast and are known to be reputable.

 

[MAF1008]

Thanks. I'm pretty sure I have the CANBUS version so I'd need a replacement motor to also be CANBUS, no?

Also- someone wrote on Facebook where I posted this that I should just have the motor itself repaired. This person said the problem is almost certainly the stator or the controller board. I checked, and Greenbikekit.com has the stator for $100 plus $40 shipping. Not bad. The controller is only $115 there. Shipping for both is $50. So $140-265 for the parts is much, much more digestible than $840 for buying a whole new motor.

But I've never serviced or even opened up my motor before. So not sure if I can do this myself, or even if I have all the relevant tools.

 

[ElevenAD]

Thanks. I'm pretty sure I have the CANBUS version so I'd need a replacement motor to also be CANBUS, no?

Also- someone wrote on Facebook where I posted this that I should just have the motor itself repaired. This person said the problem is almost certainly the stator or the controller board. I checked, and Greenbikekit.com has the stator for $100 plus $40 shipping. Not bad. The controller is only $115 there. Shipping for both is $50. So $140-265 for the parts is much, much more digestible than $840 for buying a whole new motor.

But I've never serviced or even opened up my motor before. So not sure if I can do this myself, or even if I have all the relevant tools.

If the original motor still has low miles this is no question the rout i would take before shelling out for a new motor, just saying that is a big price difference.

 

[Gionnirocket]

Thanks. I'm pretty sure I have the CANBUS version so I'd need a replacement motor to also be CANBUS, no?

Also- someone wrote on Facebook where I posted this that I should just have the motor itself repaired. This person said the problem is almost certainly the stator or the controller board. I checked, and Greenbikekit.com has the stator for $100 plus $40 shipping. Not bad. The controller is only $115 there. Shipping for both is $50. So $140-265 for the parts is much, much more digestible than $840 for buying a whole new motor.

But I've never serviced or even opened up my motor before. So not sure if I can do this myself, or even if I have all the relevant tools.

As for replacing parts I believe you'll find videos on YouTube. GREENBIKEKIT.COM has a few good videos themselves.
If you're happy with the operation of the CANBUS then you should stick with it, especially if you aren't a DIY guy. I believe more recent versions of the CANBUS are more refined than the initial release that everyone hated.
The UART version allows for end user tuning which is nice but requires some technical skill and you'll also need to change the wire harness, Display and possibly other electrical hardware like the speed sensor so I would research more thoroughly before going that route. None of this is rocket science and fairly easy IMO.
This all said... I'm a UART man myself

 

[JRA]

I was led to believe that when you swap out controllers you need to "clock" the new one to the motor. Maybe not the right term but it does involve a specialized electronic device that I figured in the end I would have no idea of how to use and I am not shy about mechanics. If you could find someone that is knowledgeable about the workings of the M620 motor then a rebuild would be a good way to go and probably save you a few bucks. Otherwise I just found it easier to swallow the cost and get the whole motor as it is easy to replace actually with only one specialized tool, a crank puller, which is readily available and cheap.

 

[Gionnirocket]

I was led to believe that when you swap out controllers you need to "clock" the new one to the motor. Maybe not the right term but it does involve a specialized electronic device that I figured in the end I would have no idea of how to use and I am not shy about mechanics. If you could find someone that is knowledgeable about the workings of the M620 motor then a rebuild would be a good way to go and probably save you a few bucks. Otherwise I just found it easier to swallow the cost and get the whole motor as it is easy to replace actually with only one specialized tool, a crank puller, which is readily available and cheap.

That is another valuable point on replacing the CANBUS controller.
You need the CANBUS tool.

Something similar needs to be done when replacing the UART rotor but you need the 961 Display as a tool.

Anna Lee at Greenbikekit.com is typically helpful answering questions.
[email protected]

And for your viewing pleasure.

 

[MartsEbike]

Thanks. I'm pretty sure I have the CANBUS version so I'd need a replacement motor to also be CANBUS, no?

Also- someone wrote on Facebook where I posted this that I should just have the motor itself repaired. This person said the problem is almost certainly the stator or the controller board. I checked, and Greenbikekit.com has the stator for $100 plus $40 shipping. Not bad. The controller is only $115 there. Shipping for both is $50. So $140-265 for the parts is much, much more digestible than $840 for buying a whole new motor.

But I've never serviced or even opened up my motor before. So not sure if I can do this myself, or even if I have all the relevant tools.

I'd have guessed the stator too.

If you take the cover off the side you might be able to see if your coils are burnt out/discoloured. If so that's probably the cause of your power loss.

 

[mail_e36]

Hi @MAF1008 curious how your motor situation worked out?

 

[MAF1008]

I decided I was so busy that I didn't have time to try to do the motor repair myself. So I ordered a full replacement motor on the morning of May 31st from California Ebike. I ordered from them because the price was similar to that of greenbikekit, but I thought I'd have better luck and receive it more quickly by ordering from a US retailer. It still hasn't shipped, and they haven't been responsive to my email inquiries since last Thursday. I also tried calling yesterday and just got a machine. I'm now worried I've been scammed.

 

[il Munduato]

I decided I was so busy that I didn't have time to try to do the motor repair myself. So I ordered a full replacement motor on the morning of May 31st from California Ebike. I ordered from them because the price was similar to that of greenbikekit, but I thought I'd have better luck and receive it more quickly by ordering from a US retailer. It still hasn't shipped, and they haven't been responsive to my email inquiries since last Thursday. I also tried calling yesterday and just got a machine. I'm now worried I've been scammed.

Surprised... They've been pretty solid in the past.
Hopefully you'll get it soon.

 

[m@Robertson]

I decided I was so busy that I didn't have time to try to do the motor repair myself. So I ordered a full replacement motor on the morning of May 31st from California Ebike. I ordered from them because the price was similar to that of greenbikekit, but I thought I'd have better luck and receive it more quickly by ordering from a US retailer. It still hasn't shipped, and they haven't been responsive to my email inquiries since last Thursday. I also tried calling yesterday and just got a machine. I'm now worried I've been scammed.

Cali Ebike is a solid operation but I believe it is also run by a single individual now. I have bought from them repeatedly over many years, most recently a Lekkie 28T chainring I got in a few days just about a month ago. I would try again via email. They usually respond in a day or so. A few months back they had a stock issue with a OneNut and socket I ordered and they held the order waiting for the socket. I inquired and after hearing the situation cancelled the socket order and got a partial refund.

 

[JRA]

I didn't see the 52v UART version listed on CA. eBike and that was why I suggested GreenBikit which does? If you worked out that is what you needed with CA then that is probably the hold up as they have to special order it from Bafang in China. Hopefully you will receive it soon!

 

[MAF1008]

They had the 52v CANBUS version listed, which was the version I needed and what I ordered on their website. I just finally received an email from them saying that they had a miscount and only have the 48V version in stock. I'm going to get a refund. I appreciate that they finally got back to me and didn't try to just steal my money, so they're not scammers, but really, they should have come to the determination that they couldn't ship the order within a few days, or at most, a week. I know a small business isn't Amazon, but sitting on an order for two weeks is not acceptable. And that's aside from listing an item as available when it isn't. I could have received a shipment from Hong Kong already.

I just placed the order at Greenbikekit. Hopefully it ships soon. I have a feeling they will ship it within a day or two.

 

[MartsEbike]

I just placed the order at Greenbikekit. Hopefully it ships soon. I have a feeling they will ship it within a day or two.

GBK are normally pretty good, but i did just wait a week for them to dispatch my last order. Add another week or so for delivery from china and it adds up to quite a wait!

 

[il Munduato]

Wasting two weeks sucks... They should have at least checked inventory when the order was received. Especially on a high price/low inventory item of which I can assume they typically don't have 100 motors sitting on a shelf.
I've gotten stuff from GBK relatively quickly but it was mostly light weight items like covers and gaskets. <2 weeks
Looks like the best US retailer is in China.... Hang in there.

 

[kevinmccune]

thats the trouble with these electric razor motors,stick a good g060 or g062 on the back and dont look back( if you have a cassette or freewheel a good 060 with at least a 25 amp controller has a lot of grunt currently have a new 24' x4 comfort cruiser i am putting together,finally had to give up on the lightweight hero bikes,just turned 68 and the past couple of months have knocked the daylights out of me.

 

[il Munduato]

I just ordered a motor and controller from GBK and they shipped in one day.
Anna was super helpful and responsive.
Motor (UART quiet gear) and Controller serial number dates are May 2024 build.
I chose slow boat from China as I'm in no rush so I'm planning on up to 30 days travel time.
FedEx handles the last leg from Cali to NY.

 

[DDBB]

I've read a fair amount of ultra motors needing replaced on this and other forums. Is there any sort of life expectancy for these motors? I've got a little over 1,000mi. on mine. Haven't opened it up yet as it's still very quiet

 

[il Munduato]

I've read a fair amount of ultra motors needing replaced on this and other forums. Is there any sort of life expectancy for these motors? I've got a little over 1,000mi. on mine. Haven't opened it up yet as it's still very quiet

>4000mi on my current motor and it's working perfectly. Opened it up at 1000mi to grease it with Mobil SHC100 and everything looked fine at that point. The motor is quieter now then when new and I have the older motor predating the release of the "quiet gears".
My order is for another project.

That said it really comes down to how you use it. If you know it's limitations and treat it as designed "an ebike motor" I can see it lasting a very long time.
If you ride it like a rented (mule) motorcycle... You'll be one of those on here asking "how do I fix this ***"

>11000mi on my BBS02B without a single issue. And don't get me wrong, I don't baby my bikes and do take them off road with some very steep climbing and put my suspension to full use...
I just understand that it's a bicycle and not a gas powered motorcycle.