1st Build Q100--performance problems

[motomech]

The Q128 is one of the oldest designs of the current offerings and it shows. It's really wide for a mini and a couple of members here(including D8veh)have commented on it's low power to size ratio.
That leaves the rather confusing array of SWGKH..etc. motors. They are not offered as kits by BMS Battery, so one must look to one of the other Chinese vendors if a kit is desired(the only way to go for a mini I.M.O.)..
One of the best things about the MXUS is it's wheel build and the Cute, while not having the best wheels(they are ok after "tuned-up"), is a well intergrated and well proven kit.
Also, adding oil/oil-cooling to Bafang minis is not a good idea because of the string used to tie the coils and locate the Hall wires.
Lastly, the wires on the Bafangs exit on the freewheel side(as does the MXUS, I use the frt. whl. version). With the Cutes, the wire exit on the brake side.

 

[chas58]

Thanks for all the good input!

Mototech, What battery input were you using when you wrote:
“.With my fast wind rear Q100[stk. controller], my no-pedal top speed is in the 20 to 21 mph range, but with it's "power limited" no-load speed, I am able to input with my bike's 11T/44T gearing up to 25 mph. Very nice “

That sounds pretty similar to my goal for the road bike. That is what I hope to create.

I’m building two bikes. Power is 36V10Ah:
1) Mountain bike which I would like to top out with pedal assist at 20. Looks like it goes about 15-17 now, which is slower than I would normally ride it without a motor on the road. I’ll have to try it out on slower dirt trails, where it might be useful. Motor is slow wind Q100. Goal: Motor optimized for 5-20mph.
2) Road bike which I would like to top out with pedal assist around 26. Wheel build is in process (waiting for rim to be shipped). Motor is Fast wind Q100. Goal: Motor optimized for 15-25+ mph.

 

[d8veh]

Just for imformation, I built a 2wd bike with twin 328 rpm motors. It was very fast and still quite light, but after over-heating, the motors wouldn't start. We took them off and tried lots of different controllers, but they would both only run sensorless with a KU96 controller, and were rough like that. They were smooth with every other controller when they started, but only started about one in ten times. I left the rear motor in my friend's garage in disgust. He recently put in in the back of his bike using a spare KU63, and it runs perfectly. The power isn't really enough to get me going with just this motor, but using the Bafang at 22 amps to get up to speed, then the Q100 takes over, and the bike really flies. I'd guess it's pulling to about 30mph down-hill. This combination of a 201 rpm motor on the front and a 328 rpm one on the back seems pretty good, but I guess it would soon slow dow to 15mph in a head-wind. For two motors, you need a battery that can give at least 30 amps. We're using a 12aH 36v Headway pack from BMSBattery.
Here's the bike:

 

[chas58]

Good feedback.

I think mototech is right, the 270 MXUS might be best for me, although I guess running the 201 at ~48 volts will get me in the 270-300 rpm range.

With the cutes, choosing between a 201 rpm version and a 328 rpm version leaves a pretty large gap. But for normal applications I guess its not really designed to go much over 15mph.

Running the 328 on the 700c wheel will be interesting – I expect it will only work well above 15mph and plan on using my legs below that point.

 

[motomech]

Thanks for all the good input!

Mototech, What battery input were you using when you wrote:
“.With my fast wind rear Q100[stk. controller], my no-pedal top speed is in the 20 to 21 mph range, but with it's "power limited" no-load speed, I am able to input with my bike's 11T/44T gearing up to 25 mph. Very nice “

That sounds pretty similar to my goal for the road bike. That is what I hope to create.

I’m building two bikes. Power is 36V10Ah:
1) Mountain bike which I would like to top out with pedal assist at 20. Looks like it goes about 15-17 now, which is slower than I would normally ride it without a motor on the road. I’ll have to try it out on slower dirt trails, where it might be useful. Motor is slow wind Q100. Goal: Motor optimized for 5-20mph.
2) Road bike which I would like to top out with pedal assist around 26. Wheel build is in process (waiting for rim to be shipped). Motor is Fast wind Q100. Goal: Motor optimized for 15-25+ mph.

I run Lipo 12S which is around 46V with the controllers mod'ed to 17 Amps.
With a 26" drive wheel, both the 201 and the 328 will top out around 21 mph.
The difference is;
The 201 will not gain much by pedaling, no matter how much effort is put in.
The 328, on the other hand, will hang in there longer, but you will need to be a very good cyclist to reach 27 mph. 25 mph is probably more attainable.
The 201 climbs better, the 328 fall on it's face at anything more than 6 or 7 % grades.

 

[chas58]

I'm a very good cyclist. 25-27 MPH on the road bike would be fine.

Still, sound like not many people run a cute at 36v

The 201 will not gain much by pedaling, no matter how much effort is put in.
The 328, on the other hand, will hang in there longer, but you will need to be a very good cyclist to reach 27 mph. 25 mph is probably more attainable.