Can you help me to choose a new motor?

[bjumoja]

I am planning to setup a second e-bike to use in the area where I live. I live in an area wilth steep hills and I'm aware of the 15mph rule but when I'm going up hill using my current road legal 250w Bafang 24v motor it's crawling along at abount 8mph with my assistance.

Can any of you guys propose a reliable, powerfull and if possible quite rear hub motor and battery ( plus supplier if you know one ). I will need a motor that will take me over the 15mph rule to allow me to get a decent speed up hills.

Thanks

 

[aseb]

did you check out through the earlier posts eg my similar question. I have similar problems but with 36V battery. Use the search to check through for other posts. It's worth looking through past posts in other ebike forums too.

Could your motor stand a 36V controller and battery?- that'd give a boost. Or look at the kits on ebay.

A play with the simulator at ebikes.ca might be interesting but it doesn't have all available controllers. Pick the closest to yours and its current handling (20A is lowest), use a lower spec motor (eg Golden 500W) and see the effect of increasing Voltage, Controller (Max Amps), and some of the more powerful motors.
What is the maximum rating of your controller- not the 200/250W nominal figure?

 

[NRG]

If you want better climbing ability you need more power, which means a higher current rated controller and probably a larger battery. The Bafang motor will take 36v and this will increase your speed by a quite a lot, however, remember hub motors are stuck in one gear only and when climbing hills they are best kept turning at about half of the top speed on the flat. This is where they give good torque with good forward motion, drop below and the motor generates heat instead of forward motion.

Each motor is wound (configured) for a given voltage and wheel size that will give it's max speed at or near the legal speed limit of 15.5 mph, so by raising the voltage to 36v you will end up with a dilemma as you now need to maintain quite a high speed on the hills compared to before, this may be uncomfortable and not desirable...

Edit to add, you don't want to put too much strain through the gear set on the Bafang motors as they can strip the teeth, keep to 15amp for safe operation....and if pushing it at 20amp make sure you give the motor assistance and treat it gently from standing starts and slow hill climbs. IE when there is the greatest amount of stress on the motor.

 

[NRG]

Thinking about this a bit more it may be a better solution to just go for a BPM motor, controller and battery and be done with it....BMS Battery can supply the kit

 

[bjumoja]

Many thanks guys I will look into this BMS Battery kit.