The new d-Series BionX (monster) motor

[Cephalotus]

This isn't a joke or a fake.

BionX introduced a huge (and slim) direct rear drive hub motor, the new d-series :

weight: 3,9kg

continous power: 250% more than previous BionX motors...

officially sold as a 250W motor in Europe.

http://products.wheeler.ch/media/catalog/product/cache/10/image/2300x/602f0fa2c1f0d1ba5e241f914e856ff9/i/m/image_1820.jpg

http://products.wheeler.ch/media/catalog/product/cache/10/image/2300x/602f0fa2c1f0d1ba5e241f914e856ff9/i/m/image_2164.jpg

https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-prn2/1277639_561827043853210_848638553_o.jpg

 

[t3sla]

View attachment 1

View attachment 2

 

[Architectonic]

With a hub motor of that diameter, I'd want some decent performance!

More info:
http://www.bionxinternational.com/en/news-events/news/article/?tx_ttnews[tt_news]=125&cHash=691dafffb6484f084509d265f279d293

Seems to be a "non structural" motor cover.

 

[mlt34]

with a motor that slim, the efficiencies can't be very high. The usable magnetic flux coming from the flat part of the wire turns is going to be pretty small compared to all that wasted copper in the ends of the turns. This seems like someone thought more about appearances than functionality when they designed it.

A 250 watt motor that is 250% more powerful than the previous generation? What does that say about the last motor?

 

[Cephalotus]

with a motor that slim, the efficiencies can't be very high. The usable magnetic flux coming from the flat part of the wire turns is going to be pretty small compared to all that wasted copper in the ends of the turns.

Probably not if the coils itself are rather small (and if you have plenty of them)

A 250 watt motor that is 250% more powerful than the previous generation? What does that say about the last motor?

It's about higher torque. Maximum torque is not so different: 50Nm vs. 40Nm, but continuous torque has significantly improved from 9Nm to 25Nm, at least the spec. sheets do say so.

A 250W sticker is very important in Europe. If you are involved in a bad accident with an illegal motorcycle you will have a significant financial problem propably for the rest of your life. A legal motor (with CE sign) is highly recommended in that case. Nonetheless the 250w is only "permanent power" with no further definition, so my old legal BionX Systems (G1 motor and SL motor) will take up to 30A at 48V which is almost 1500W of battery power for peaks.

The 250W is not the problem in Europe, the 25km/h (+tolerance?) is the limiting thing. There are legal 45km/h options, but you can't built them on your own. Everything beyond that is an (electric) motorcycle that needs propper insurance, license plate, drivers license, etc...

We have millions of e-bikes in Europe now, so I asume that it is a signifikant marekt.

Bionx had huge quality problems in the past on currently the Bosch systems are clearly the market leaders, also because of perfomance when climbing steep and long hills. The d-series is aimed at that market, I assume.

For those that want to built electric motorcycles with 5000W motor power a bicycle-look and some (pseudo) pedals other motors surly are more relevant.

To built a legal DIY pedlec in Europe a motor with a CE sign and a 250W sticker is what you need.

For me the BionX offers the option to have two consoles. A legal one with 25km/h limit (+tolerance) and another one for riding in other situations without a speed limit, which translates to around 40-45km/h topspeed in a 29" wheel.

 

[cal3thousand]

So it's not an axial flux motor but it's still a huge diameter? Or is it?

 

[Cephalotus]

I upgraded my speed pedelec (legal up to 45km/h) to the BionX d-series.

Main reasons:

the 9x freewheel is quite loud and does not last long in an speed pedelec when you mostly ride on the small sprockets
a cassette with smaller steps (like 11-12-13-14-...) could be useable when you ride/pedal at high speed
the SL motor gets to hot at high speed (and uphill)
The SL motor does not reach 45km/h when the 48V (13s) battery is at 50% SOC.

In a test ride with the d-motor the bike was able to reach more than 50km/h when the battery was at 90% SOC. I will limit this to 45km/h to not lose of the insurance. Acceleration was very good, this is definitely not a 250W motor as the EU sticker says. The SL motor also had much more power than just 250W.

Complete rear wheel (d-motor, spokes, rim, tire, braking disc, 9 speed cassette, ...) weights around 6.1kg, the original wheel with the bionx SL and a more heavy weight 9x freewheel is 5.8kg.

You can hear the motor slightly, there is some minor humm.

In the city test ride was not able to get the motor hot, console said that motor controller temperature was just slightly above 40°C at 17°C outside temperature.

Quite interesting is the temperature of the plastic motor housing, see picture...

 

[Cephalotus]

This was a short uphill test drive at 3-7% slope with around 1000-1100W power at the wheel (estimation from http://www.kreuzotter.de, this includes my own moderate pedal power)



You can see peak electric power at around 1500W and continuous electric power at around 1000W. This is an EU legal "250W" motor.

View attachment 3

Downhill the hill was not steep enough (3-7%) to get significant amount of recuperation at 40km/h, mostly it was air resistance. Sadly there was significant traffic, so I had to stop upheill and downhill...



It was a cold rainy day, motor didn't get hot, I assume you can use this power continously under this conditions, ...



Motor controller temperature shown on the BionX console was never higher than 42°C. The the smaller BionX motors do get significantly hotter on that hill.

 

[Punx0r]

It would be good to know the performance limits of this motor compared to the more common ebike hub motors. I guess heat dissipation will be quite a lot worse because of the plastic covers.

 

[Cephalotus]

I can't tell you exactly.

1000W continous electric power at higher speed in cold weather conditions seems to work well as long as the battery lasts...

At low speed (and much lower efficiency) on steep hills it could be different.

The main problem with cooling the copper in direct drive motors is the air gap between stator and motor housing, I assume the motor housing material itself is a much lesser problem.

BionX motors throttle somewhere between 70-95°C measured directly on the motor controller board inside, the BionX d in that test drived measured just 42°C maximum. From my experince the older BionX SL motors would have been somewhere above 70°C in such a ride...

Overheating the SL Motor on hot summer days in my Speed pedelec (45km/h) was my main reason to try the d-series BionX, other reasons have been to reach 45km/h with an half empty battery and the use of cassettes instead of freewheels...