Bafang 350w 280rpm vs Q100h 350w 260rpm

Hi,

 

I am considering upgrading my current 36v q100 350w 201 rpm rear hub. I am currently running the motor on 36v but will change to a 48v battery any day now. Where I ride is mostly flat but with strong winds. My current q100 is really at its limit when there is a strong headwind, which makes pedaling hard.

 

My weight is 80kg and my wheel size is 26 inch. I am considering the following motors:

36v Bafang bpm2 350w 280rpm rear hub

36v q100h 350w 260rpm rear hub

36v q128h 800w 201rpm rear hub

 

Only comparing the two 350w motors, which would be recommended for taking on strong headwinds?

 

What would my expected max speed be with each of the three motors given some normal pedaling and no wind?

 

Thanks!

350W at 260RPM has too low torque against headwinds.

My recommendation for 350W motor is 230RPM on 26" wheels.

I have tried the Q128 800W 48V kit from bmsbattery, it's a good motor and about 1.3kg lighter than a 350W Bafang BPM.

https://bmsbattery.com/ebike-kit/776-q128h-48v800w-rear-driving-e-bike-motor-wheel-ebike-kit.html

Interesting. But I thought the q100h 260 rpm had 30% more torque than q100 201 rpm?

no, it's the other way round. More Volts = more torque, more speed.

Slow winding: more torque.

are you sure, the bms battery claims 30% more torque for q100h. of course i should compare motors with the same rpm to begin with.

 

what is the difference in terms of speed and torque between a q128h at 36v vs 48v given that i run it with a 48v battery?

I only rode the test bike fitted with q128 48V 800W, not the 36V version. If you compare a 20A 36V controller against a 20A 48V controller on the same Q128 motor, you get 30% more torque at the same speed and 30% more speed at the same torque, or a combination of the two (15% more torque at 15% more speed). But if you use two different motors, it will not be straightforward, you will need to test ride them to compare.

Be careful with the ratings (Bafang 350W vs Q128 800W), they are just for labelling.

 

Interesting. But I thought the q100h 260 rpm had 30% more torque than q100 201 rpm?

 

Sorry I missed the H in your post. I don't know the difference between the Q100 and Q100H.

Edited December 9, 201510 yr by trex

I belive D8veh tested the q100 vs q 100H and reported not much difference in real life.maybe 10%

I have only tested tthe q128H motor and are very impressed with it.It says 201 rpm,but the motor I tested had a top speed of 34kph so I think it is closer to 260 rpm.Strong climbing and takes a lot to get hot

 

https://bmsbattery.com/ebike-kit/776-q128h-48v800w-rear-driving-e-bike-motor-wheel-ebike-kit.html

thanks to both of you for the info. q128h seems like a good choice, my only fear is that it will eat much more battery than the q100 and thus significantly decrease my distance.

 

1boris, do you know if you tested the 48v or 36v version?

 

i have a 36v/48v controller with max 17a. Do i need to upgrade to more amps if i buy a q128h?

thanks to both of you for the info. q128h seems like a good choice, my only fear is that it will eat much more battery than the q100 and thus significantly decrease my distance.

 

1boris, do you know if you tested the 48v or 36v version?

 

i have a 36v/48v controller with max 17a. Do i need to upgrade to more amps if i buy a q128h?

 

The motor on the link i posted only comes in one version 36v 201 rpm.But the listing of the rpm must be wrong.Its around 260 rpm.I tested the motor with 48v 18amp and it worked great.top speed throttle only about 43-44 kmh.But I could pedal it faster on the flat

if you are interested by the Q128H, check first if your existing controller has Hall (your motor cable has 9 pins instead of 3 pins). If you are interested in going for 48V, buy the whole kit from bmsbattery. This 48V kit is certainly a good for the money and I think 48V is the way to go for hub kits.

On the negative side, the LCD3 is fiddly to get right, the motor needs a 9-pin extension cable to go between the motor connector and the controller (supplied with the kit but is too long, leaves about 2ft of motor cable to lose). The kit also does not come with external speed sensor, I think it shows speed from pulse counting.

Trex, this is my new controller. it has a hall cable but i am not sure about the 9 vs 3 pin. Would you please explain?

 

Just seen this a bit old now so I expect you will have worked it out now ?

Hall motors will have a multi pin (9) connection and non hall just a 3 pin connection for the 3 phase. Most 9 pin connectors (male) will mate in to a female wire connector usually along the rear frame stay (most tend to be on the right except Xiongda left) at the other end of the female wire connector the wires terminate as 5 hall with a block connector , 3 phase wires blue, green & yellow are fairly standard and the ninth may be white and not used.

<<<I belive D8veh tested the q100 vs q 100H and reported not much difference in real life.maybe 10% >>>

Yes, I agree with that. It is thought that the "H" gets it's extra power handling from higher quality magnets.

I have used every Cute version and here is my take on them;

Q100H 201(actual no-load rpm @36V=230) vs. Q100H 260(actual no-load rpm @ 36V=260). There is little difference felt on the road. The 201 "jumps" off the line a little better, both climb about the same. On 48V, the 201 tops out @ 19 mph, the 260 @ 22 mph. Except for off road or use in a 700cc wheel, I would pick the 260 every time. Both will live happy on 48V/20Amp. This is about the most powerful system I run on the frt. whl.

For rear whl. fitment,there is a choice of free wheel vs. Cassette. For cassette, the Q100C is available in 210 or 328 speed ranges, and standard(non H) configuration. Aside from being down 10% from the "H" and having less than optimum gearing, the stator on the "C" is 20% narrower, so down 30% from "H" model in power handling. The Holly Grail for us Cute users would be a Q100HC "260", bit such a thing doesn't exist. It is thought that the 260 gears would fit the latest "C" models, but those gears are only available by buying the complete motor.

The Q128 offers a better cassette option;

The Q128C is offered as a 328 in a 48V motor. This would be approx. 290 rpm @ no-load, so @ 36V, it would be a 260 rpm no-load. A mid-speed motor, not a high speed, like the 328 @ 36 V.

One thing I have not been able to determin concerning Q128 fitment is, clearance when used w/ a 140 mm brk. rotor. We think ois is very close and a 160 rotor might have to be used. A member on ES is waiting for a Q128C to check this.

Excellent Motomech thanks for you input, re the 128c 328rpm 48v any idea of mph it will do if run at 36v.

Excellent Motomech thanks for you input, re the 128c 328rpm 48v any idea of mph it will do if run at 36v.

Same as a Q100 260. In a 26" wheel, around 19 mph.

You can see @ the Ebike CA sim. Use the Outrider standard as a sub for the Q100H 260. They have the same no-load motor speed and performance profile.

 

http://www.ebikes.ca/tools/simulator.html

Edited March 25, 201610 yr by motomech

I went on my bike Q128C 201rpm/36V version with 48V battery on strong winds 2 weeks ago. Motor has no problem whatsoever to maintain a 30kph+ speed. With or without human assistance. Drains battery though.