Need advice - a good 250W-ish 24V motor

Hi, I'm going now for a second ebike project. My better half, having seen the light, decided she wants an ebike too.

I already have a 24V battery in a pretty good condition, Samsung 22F cells with a nominal 8Ah of total pack capacity. I'm hopeful this would be good for 30km/19miles of mild assistance, maybe more.

Here's what I need:
*likely a 26" rim
*the whole bike doesn't need to go over 25kph/16mph, but it should be capable of offering some assistance up to 20kph
*I rather have more torque than max speed for uphill assitance
*regen braking is not important, bonus if I get it; lightweight is more important

I need then a motor that does 200RPM on 24V and a decent controller to go with it. Most of the things I find on amazon or ebay are either 36 or 48V with no info on the winding or the RPM.

Opinions, advices? Geared/gearless? Which one?

First off, a 24 V system is practicly useless, even on a low speed "assist" bike. Here's why;
Geared mini motors come in 3 speed ranges, they are;
The "201" low-speed motor.
The "260" mid-speed motor.
The "328" high-speed motor.
The voltage rating of a motor is not important except it's effect on the speed rating, usually measured as rpm @ 36V. So we will talk about 36V motors.
Using the Ebike CA sim., we get these speeds for a 24V battery powering a bike w/ 26" whl.s.
201 = 11 mph
260 = 13 mph
328 = 16 mph

On paper, the high speed motor looks to be just what you want, but there is a fly in the ointment. It will be very slow to get going and it will be a poor climber.

It is always better to use the highest Voltage w/ the lowest speed motor to get the top speed desired, it will be more efficient and a better all around performer.
For example, the 201 low-speed motor on 36 V will top out at 16 mph and climb hills decently.
A 201 on 48V will top out @ 18-19 mph and , with a lighter person, climb pretty much any hill one would encounter.
But since you have the 24 V battery, it can be done w/ the 328, just make sure the battery is in good enough shape to be worth while. And if it's a SLA batt., forget it.
We are talking about a bike w/ very low power, so a frt. mount, geared mini would be the easiest install and still be safe. One good source would be;

https://bmsbattery.com/ebike-conversion-kit/591-q100-36v350w-front-e-bike-motor-wheel-conversion-kit.html

Controllers range from fancy "sine wave" models w/ a display and "torque imitation" PAS to plain ones.
The sine wave you would be looking at is;

https://bmsbattery.com/ebike-kit/546-s06s-250w-torque-simulation-sine-wave-controller-ebike-kit.html

Note that that controller is rated 24V/36V, it adjusts automaticaly to the batt. Voltage.

A very good "plain" controller would be;

http://www.ebay.com/itm/24V-36V-250W-6MOSFET-ebike-Electric-Bicycle-Brushless-Motor-Controller-with-LED-/322385783474?var=&hash=item4b0fb0aab2:m:mgxcwDHTuIgK4sxrLPhfyrQ

Since the shipping is only $8, it is NBD to order septerately. This Co. is Elifebikes, the other recommended vendor from China. I don't see that they offer a motor/wheel combo, already built, which is what you want. But using their Ebay store, you can split your order between BMS Battery and Elifebike and not incur too much costs in shipping.

You could do some reading on controllers and what they offer.

This kit would be perfect:
https://bmsbattery.com/ebike-kit/291-q100-24v250w-350w-front-driving-e-bike-kit-ebike-kit.html

Normally, I'd say that you need several levels of PAS, but at 24v maximum power all the time will be fine. If you/she finds it too much, you can always swap the controller for the S-KU65 and three-level LED display. The S06S and LCD is much better and works at both 24v and 36v, so when it comes to the time to replace your battery, you can get a 36v one for 50% more power, if you want.

Hey guys, thanks for the feedback. I understand better what's required, but it's not quite what I need. Basically I'd say the last suggestion is good, but I need it in RWD.

I do understand at 24V it's hard to make the speed I need, especially if you want any kind of torque - and torque is the main objective. So I'll get on searching a 200RPM motor (under 36V as it seems), which should translate into 200x24/36*0.8 = about 11mph loaded speed; not a lot, but serviceable. Hopefully I can cram enough torque in this setup to give a decent boost.

@d8veh - I see you're on the pedelcs forum, too. You're sure bmsbattery ships to the UK?

If bmsbattery is a good option for me, then I'm looking at the Q100H or Q128H RWD

motomech said:

First off, a 24 V system is practicly useless, even on a low speed "assist" bike. Here's why;
Geared mini motors come in 3 speed ranges, they are;
The "201" low-speed motor.
The "260" mid-speed motor.
The "328" high-speed motor.
The voltage rating of a motor is not important except it's effect on the speed rating, usually measured as rpm @ 36V. So we will talk about 36V motors.
Using the Ebike CA sim., we get these speeds for a 24V battery powering a bike w/ 26" whl.s.
201 = 11 mph
260 = 13 mph
328 = 16 mph

On paper, the high speed motor looks to be just what you want, but there is a fly in the ointment. It will be very slow to get going and it will be a poor climber.

It is always better to use the highest Voltage w/ the lowest speed motor to get the top speed desired, it will be more efficient and a better all around performer.
For example, the 201 low-speed motor on 36 V will top out at 16 mph and climb hills decently.
A 201 on 48V will top out @ 18-19 mph and , with a lighter person, climb pretty much any hill one would encounter.
But since you have the 24 V battery, it can be done w/ the 328, just make sure the battery is in good enough shape to be worth while. And if it's a SLA batt., forget it.
We are talking about a bike w/ very low power, so a frt. mount, geared mini would be the easiest install and still be safe. One good source would be;

Q100 36V350W Front E-Bike Motor Wheel RPM 201

Q100 36V250W-350W Front Driving Disc Brake, V-brake and rim brake compatile E-Bike Motor Wheel. You can select S06P, S06S or LSW-675 controller for this motor.

bmsbattery.com

Controllers range from fancy "sine wave" models w/ a display and "torque imitation" PAS to plain ones.
The sine wave you would be looking at is;

https://bmsbattery.com/ebike-kit/546-s06s-250w-torque-simulation-sine-wave-controller-ebike-kit.html

Note that that controller is rated 24V/36V, it adjusts automaticaly to the batt. Voltage.

A very good "plain" controller would be;

24V/36V 250W 6MOSFET ebike Electric Bicycle Brushless Motor Controller with LED | eBay

When you press 6Km/h button and hold it, the ebike will run at 6Km/h speed as your walking speed, and you don't have to push the bike advance since it can run with your normal walking speed. 36V 250W Max.

www.ebay.com

Since the shipping is only $8, it is NBD to order septerately. This Co. is Elifebikes, the other recommended vendor from China. I don't see that they offer a motor/wheel combo, already built, which is what you want. But using their Ebay store, you can split your order between BMS Battery and Elifebike and not incur too much costs in shipping.

You could do some reading on controllers and what they offer.

Click to expand...

HI . how does a currie motor 24 v (on the side of back wheel) compare to climb hills to a

Q100 24V250W-350W FRONT DRIVING E-BIKE KIT​