500w BPM kit from BMS Battery

[John_S]

I'm considering getting the 48v 500w rear BPM conversion kit from BMS Battery. I want to convert a bike for my dad to ride. I already own an e-bike myself. I'm concerned about the legality issue of the 500w kit, however. If I were to buy this kit, do you think is it possible that BMS Battery would be willing to put a 250w label on the motor at my request? Have they done this for any of the rest of you guys on this forum? Thanks.

 

[Tabs]

The general opinion on here is that the geared motors are best for all-around everyday use,if the 500w bpm is geared id just go for it but if its not id go for 250/350w geared motor,nothing to stop you putting your own sticker on the 500w motor

 

[1boris]

Xiongda have the same motor and also as a cassette version .and they have been willing to mark it as a 250w 48v motor for me before.email Bonnie at Xiongda and ask for a price for the motor or the complete kit. epost: bonnie@xiongdamotor.com.cn
I got a price for motor only 6 months ago 98 usd for a cst version motor.

ABout the YTW-05, it can be 48V500W, marked 48V250W is ok.
However we only have CE certificate for 24/36V motors.
price:
YTW-05 thread-on freewheels-------93USD
YTW-05 lock-on cassette--------------98USD
20ah controller----------------------------22USD
lacing 700C rim---------------------------35USD
deliver cost------------------------------75USD(one motor kit)
-----------------------------147USD(one 700C kit)
700C 35km/h is ok, with a display and controller can limited it to 25km/h.
The torque is around 40N.m, not sure if it burns for your road condition.
copper inside affects the motor speed, not motor's torque.

 

[Deleted member 4366]

The 48v BPM and it's various clones and derivatives are real brutes - great for people that can't pedal. Does he need that much power?

You won't get BMSB to mark one 250w. They're engraved at the factory. Xiongda are pretty good though. They make a whole range of motors. If you buy the complete kit from them, make sure that you specify a KT controller.

 

[John_S]

Thanks for your replies. If the YTW-05 is the same motor as the BPM from BMSB, and Xiongda can mark it 250W, then that would be the better choice, especially seeing as they do a cassette version which would be my preference. If I do order the kit, I'll make sure it includes a KT controller. What does the "KT" stand for?

 

[Woosh]

What does the "KT" stand for?

Kungteng electronics

http://www.szktdz.com/en/

 

[John_S]

Kungteng electronics

http://www.szktdz.com/en/

Thanks for this information Woosh. Their controllers look to be of very high quality.

Boris, do you know if the YTW-05 comes in a range of winding speeds like the standard BPM does? My dad lives in a hilly part of North Wales, and a version of the motor that has a slow winding speed and therefore high torque is what would best suit his needs.

 

[Woosh]

Boris, do you know if the YTW-05 comes in a range of winding speeds like the standard BPM does?

I don't know John.
The simplest solution for your Dad is the BPM running on 36V 25A. You want low voltage and high current.

 

[Deleted member 4366]

I don't know John.
The simplest solution for your Dad is the BPM running on 36V 25A. You want low voltage and high current.

No. You want high voltage and low current with a low winding-speed motor for best climbing.

 

[antenorareal]

Can you please explain why?
I thought it was the other way...

Enviado do meu SM-G850F através de Tapatalk

 

[Woosh]

A low speed winding is normally not available off the shelf.
If you can specify directly what you want, then it does not matter which voltage you want to run your motor, the factory will make the motor to your exact requirements.
In practice, you can only choose from the range that your supplier carries. The info is on the label, like this:

Ask your supplier which one of theirs is best for what you want to do.
This motor on the woosh zephyr B is used with 20A controller but the motor can be used with a 36V 25A controller,
On the zephyr B, it has a noload speed of about 21-22 mph. If you run it with a 25A controller, the noload speed stays the same but the torque is 25% higher.

 

[John_S]

Woosh, you mention that the Zephyr B (and presumably the Big Bear too) can be used with a 36v 25a controller. Do you happen to stock any 25A controllers? I'd actually be interested in upgrading to a 25A controller for my Big Bear bike if you have any available.

I'll ask Xiongda if their YTW-05 comes in a range of speeds like the BPM does. On Xiongda's website, it says the YTW-05 has a maximum torque of >30N.m., which looks to be lower than some other motors such as the Bafang G06 which is described as having a maximum torque of 80 N.m.

 

[Woosh]

Hi John,
I don't have 25A controller in stock.
The G06 is very good, but for fat bikes.
Again, you'd need 25A to get the most out of it.

 

[Deleted member 4366]

Can you please explain why?
I thought it was the other way...

Enviado do meu SM-G850F através de Tapatalk

48v is more efficient and the lower current means that you ca use a small 6 FET controller.

 

[Deleted member 4366]

Woosh, you mention that the Zephyr B (and presumably the Big Bear too) can be used with a 36v 25a controller. Do you happen to stock any 25A controllers? I'd actually be interested in upgrading to a 25A controller for my Big Bear bike if you have any available.

I tried the 350w (same as 250w) BPM at 22A, 25A and 30A. There was no difference in the power and torque. 22A is the maximum. If you want more power, you have to go to the 500W version, which can go up to about 35A. The Xiongda might be different. It will share the same castings, but could be completely different inside.

The Bafang BPMs come in a range of RPMs. If you look at the markings on the Woosh picture, you will see 26 (XX), where XX is the speed code. It looks like 12 or 13 on the Woosh one. 16 is the slowest at about 180 rpm (36v). The common codes are 15,13,12,10 and 8. I have a code 14 and I had a code 11, so they all exist from different suppliers. The problem is that most suppliers don't have a clue about the code, so they have no idea what they're selling. You have to show them a picture of the marking and ask them what XX they have.

 

[Woosh]

all the BPM on the Woosh bikes have code 13.
Noload speed about 230 RPM
d8veh, which winding code on the BPM sample did you test?

 

[John_S]

Yes indeed. I've seen code 13 engraved on the motor of my Woosh bike. Code 13 seems to be a good compromise between speed and torque.

Regarding my original query, my dad has now decided he wants to get a pre-made bike from somewhere fairly local. He's interested in the bikes that have the BPM motor from the Kudos range. There's a Kudos dealer near where he lives. They look to be wonderful bikes although its a slight shame that they have small batteries.

 

[Woosh]

AFAIK, they also have smaller 15A controllers.

 

[Deleted member 4366]

all the BPM on the Woosh bikes have code 13.
Noload speed about 230 RPM
d8veh, which winding code on the BPM sample did you test?

Code 13 or 12. I can't remember now, but it wasn't a slow or fast one.

 

[Woosh]

Code 13 or 12. I can't remember now, but it wasn't a slow or fast one.

the difference can show up in the ratio torque/cost of the system and performance at low speed.
I don't keep 12-FET 25A controllers because they are too big to fit inside the controller box.