Difference between 250w vs 350w Bafang 8Fun hub motor

[Woosh]

Woosh use the Bafang BPM in our Big Bear, Big Bear LS and Zephyr B. It has more torque at low revs than other popular and smaller geared hub motors making it more suitable for heavy riders.
For reference, the BPM weighs 4.5kg compared to the popular bafang SWXH at 2.75kg. We use the BPM code 13 which is marginally slower (no load speed about 230RPM) than SWXH (about 240 RPM) but has much higher torque (about 50NM at 8mph) against the SWXH/SWXK (about 35NM at 8mph). Bikes built with the BPM need to be restricted to be legal.

 

[Nealh]

The Woosh BPM kit has 20a controller and is pokey with great torque and crusies nicely at 19/20mph (not legal) a 201rpm wind on the road, NLS 230rpm. If you ran it at 48v still legal then you should get a nice 23/24not legal) though expect the FFP to raise their head above the parapet. The LCD if still used is a very simple and basic King meter JLCD, really easy to change parameters. It has speed , wheelsize , odo, trip, battery level and clock.
Mine has 1950 miles on it so far and I have replaced a side plate bearing at 1650 miles as it wore and slapped some more grease in at the same time, 10/15 min minor maintenance job otherwise the kit has bee ultra reliable in all weathers.

 

[Neil5403]

The Woosh BPM kit has 20a controller and is pokey with great torque and crusies nicely at 19/20mph (not legal) a 201rpm wind on the road, NLS 230rpm. If you ran it at 48v still legal then you should get a nice 23/24not legal) though expect the FFP to raise their head above the parapet. The LCD if still used is a very simple and basic King meter JLCD, really easy to change parameters. It has speed , wheelsize , odo, trip, battery level and clock.
Mine has 1950 miles on it so far and I have replaced a side plate bearing at 1650 miles as it wore and slapped some more grease in at the same time, 10/15 min minor maintenance job otherwise the kit has bee ultra reliable in all weathers.

Interesting thanks.
I take it the extra power will affect the range?
I will always use the pas as want the exercise, so although I would like a little extra speed over 15mph on pas, the range is important and needs to be 30miles plus, at least that of my Carrera E

 

[Nealh]

My 2 yo 15ah battery has lost some capacity and only now gets 41.4v max charge but still manages 28 mile range if needed, a new battery should get you 45/50 miles. The 2 yo batt with a Q128c only sees 17/20 miles. Tbh derestricting the Bpm will make very little difference on overall range.

 

[Neil5403]

How does it compare with your oxydrive CST kit?

 

[Nealh]

Both kits are good but different.
Bpm is powerful and torquey coupled with the 20a controller with top speed of 19/20mph@ 36v, you can feel the power less effort peddling is needed.
Oxy has a faster wound 270rpm hub so speed tops out at 24mph but integrated controller is a bit weedy at 15a, the pcb is embedded in silicone and the shunt isn't accessible to mod. Climbing up steep hills is god but slow 6-9mph, up the speed and assist levels then it starts to growl.
The throttle works different the Bpm/Big Bear gives throttle power all the time where as the Oxy throttle is not so good it gives power depending on which speed function you are in. Both have been reliable but for me the bpm edges it.

 

[Neil5403]

Can BPM also be had for rear hub or just front with Woosh ( spelt correctly mr Woosh!! Remove spelling rating!!)
As you say the display is basic on the Woosh. Can it be upgraded to a good display. I do like a nice display...

 

[Nealh]

The Oxy is less adaptable as the controller /battery are integrated eventually when the batteries range reduces I will run the hub with another 20a KT dual voltage controller I have and will probably run it off Graphite lipo. A nice 70/80 mile 21700 battery would be nice in years to come but feel they will be too expensive for e bikes.

 

[Nealh]

Can BPM also be had for rear hub or just front with Woosh ( spelt correctly mr Woosh!! Remove spelling rating!!)
As you say the display is basic on the Woosh. Can it be upgraded to a good display. I do like a nice display...

There is a freewheel screw gear version BPM2, don't think Woosh have them.
I love the King meter for it simplicity, its discreet and small. It does all I need able change cutoff speed and wheel size.

 

[Neil5403]

The Oxy is less adaptable as the controller /battery are integrated eventually when the batteries range reduces I will run the hub with another 20a KT dual voltage controller I have and will probably run it off Graphite lipo. A nice 70/80 mile 21700 battery would be nice in years to come but feel they will be too expensive for e bikes.

The future of battery development will be very interesting and swift with the help of Tesla etc.
What is the output of the Oxydrive inbuilt controller?

 

[Woosh]

I take it the extra power will affect the range?

insofar that the owners of these bikes tend to be heavier and because of the available power, they tend to go faster too, especially in urban areas.
The BPM is otherwise as efficient as other geared hub motors.

 

[Woosh]

Can BPM also be had for rear hub or just front with Woosh.

We have the rear BPM hub on the full-sus Zephyr-B. Due to the very high torque of the BPM, we avoid putting them on un-suspended wheels due to a small risk of breaking spokes. For kits, we leave the decision to our customers.

Can it be upgraded to a good display. I do like a nice display...

Your LCD may not have the same plug. We use Julet waterproof cable system, the most popular cabling system for kits. The LCD also needs to be programmed to talk to the controller. Different controllers (eg KT and Lishui) don't use the same protocol,the parameters stored on the LCD may not be applied correctly to your controller on startup. Generally, you cannot mix and match.

 

[flik9999]

The cyclotricity 250w fronthub kit goes at 19 mph at stock (Dont know how the hell they get away with this, selling a street legal kit that goes to 19 mph). But you can set the max speed to 17 mph with the lcd controller if you want for legal limits.