Cute Q100 lightweight builds slow mtb, fast road

chas58

10 kW
Joined
Mar 19, 2013
Messages
712
Location
Detroit, Michigan, USA
I’m building two bikes. Power is 36V10Ah:
1) Mountain bike (slow speed) which I would like to top out with pedal assist at 20. Motor is slow wind (210) Q100. Goal: Motor optimized for 5-20mph.
2) Road bike (higher speed) 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 (328) Q100. Goal: Motor optimized for 15-25+ mph. Note: this motor is not recommended for a 26”/700c wheel because it will not be happy below 15mph. We'll see how it goes.

Both bikes are about 23lbs with the hub motor. Battery either on a small camelback style backpack or on a rear rack. Those bottle batteries look nice, but I hear they don’t have much power (i.e. not much current capacity).

Stay tuned for more..

Current picture of slow speed build - the mountain bike with Q100 201rpm motor.
View attachment 9

And the the road bike with the 15-25mph motor:
View attachment 8

View attachment 6



------------ 2016 update ---------------------

Turbo drop sm.jpg
Road Bike V2.0: Road bike updated above with Drop Bars and small 1.6kg battery.

View attachment 6
Testing the road bike. 25+ mph on 36v, with a 25 mile range!

STRAVA test 25mph sm.jpg

battery.jpg
Above shows approximate size of the battery.

------------ 2017 update ---------------------
Loving the lightweight battery.

The Klein is loving the snow on its new studded tires!


Built up a full suspension stealth build to go off road (gravel, double track, snow, single track).

snow bike 4.jpg
20170226_125519-01 750.jpg
20170306_204544-01 750.jpg
20170226_160106-01 750.jpg
 
chas58 said:
Those bottle batteries look nice, but I hear they don’t have much power (i.e. not much current capacity).
Only the cheap 8.8aH ones seem to be weak. The 10.4 aH ones are better or the 6aH high discharge ones.
 
I'd recommend the smaller bottle batteries, or 10 ah pingbattery for a 15 amps controller at most. So if you want more, 20-25 amps, you need more battery or more c rate.

If trying to keep it light as the only goal, then 5 ah of RC lipo will work. Unfortunately, to have some power, and some range, you just have to pack a larger battery.

My new battery just arrived yesterday, all my huge stash of batteries is now old and dying fast. 14s 20c lipo, 10 ah. It's barely 520 watthours, and in practice (undercharge and stop early) more like 400 wh.

It's just barely enough to serve my needs, 15 mile range, 20 if I really ride super slow. With the grocery store 5 miles away, I will make that trip without going so slow. Soon as I can, I'll add some more, hopefully a second identical pack. Or at least add 5 ah more.
 
Yeah, to bump up the speed of the slow wind motor, I could either go 12s lipo (maybe a pair of 6s2p-8ah packs like Dev8h made), or a 13s4p Li Ion pack (46.8V 8ah) with a high C rate. That is only 2.6kg.

Waiting on the rim to build up the 328rpm 700c wheel. It will be interesting to see how that turns out, although that combo certainly is not for everyone. I can ride 25mph sustained if I really want to – so I’m looking for a motor that can match that and help out at those speeds. (clearly I am not the typical ebike rider).

I am fine with 14ah. I don’t need the torque, I just need speed. I have 2000 watts peak torque in my legs, so I don't need help accelerating.
 
I’ll post a link to the kit I got, but their website seems down. I ordered from Greenbikekit.com (GBK). They sell the same motors that BMSbattery (and that elifebike) sells, but seem to have better feedback than the BMS battery guys. They can also pack a bit more in a box before charging you extra shipping, so I got an extra motor. Hint: they can send you two front wheel builds for the shipping price of one! Unfortunately I am building two rear wheels, so I am getting the 26” wheel Chinese built, and the 700” bare motor that I will build with a nice deep V wheel. For the cost of building and shipping a second wheel, I would rather get the motor with free shipping and build the wheel here. (Shipping alone on the wheel build is $100-$150)

Don’t expect much customer support as these are basically just distributers/wholesalers. You are going to need a voltmeter to troubleshoot potential problems, so be prepared to get one of these if you don’t have one. You are not going to get anything useful for instructions, just a simple wiring diagram. It took me 4 days (and lots of troubleshooting) to get the bike running after the kit was installed. If you don’t have the inclination to figure this out by yourself (with help from forums), buy it from North America (assuming that is local to you).

Don’t be fooled by the prices. Shipping is going to about double the price of anything you order, especially if you have a battery. My basic kit cost $320, but was $500 delivered. A small 36v motor is a great starter kit if you like to pedal. I was tempted to get a bottle battery, but these batteries cannot deliver more than 9-10amps. That is tiny (other battery sellers might have bottles with more than 1C capacity, but not BMS and green bike kit).

My Kit: Cute Q100 36v 250-350 Watt motor and battery kit with 36V10Ah (LiFePO4) battery. Controller is a small 14amp, battery can put out 20amps. If I was to do it again, I might have gotten the headway batteries which at 10Ah, can actually put out 100 amps (10c). But that would only be useful with a bigger motor and controller. 20amps should be plenty with this kit.

Kit shipped with DHL (because of the battery) and arrived about 5 days after I ordered it. That was a nice surprise!

This should be an easy build, but never having done this before, I am coming into some problems that make me scratch my head.

Problem #1. The rear “tai light” of the rack mounted battery pack turned on and I can’t find a way to turn it off. With some emails with GBK, I find there is a hidden (almost invisible) switch under the battery handle to turn this light on and off. Never would have found that on my own.

Problem #2: bike is all wired up, and nothing happens. Grrr. Time to get the voltmeter out. Turns out I am getting no power from the battery, even though it has a full charge. So, I take the battery pack apart. There is a key that locks the case to the bike rack, but it turns out that the key has to be in the locked position for the battery to give power. Pretty easy answer. Wouldn’t a simple instruction manual be nice for small crap like this?

Problem #3 turned out to be even more aggravating…
 
Thanks to help from the insightful people here, I managed to get to the problem of my real head scratcher:

Now I have power from the battery (with the key turned on), and still nothing. I have two controllers, and 4 throttles to choose from, but nothing is working I’m not sure if I am wiring something up wrong, or if something is defective (guess which? Yep it is a quality control problem, but not from me).

I’m trying to figure out why it isn't working, if I am doing something wrong, and what is the minimum needed to get this damn thing running.

Here is the basic answer:
- Both controllers obviously have to be wired to the battery and to the motor.
- Both controllers need a throttle (or something to turn them on)
- The CON61 (AKA KU65 with LED meter) is sensored, and needs the halls wires hooked up. Yes, it will not run without this wiring. The CON 62 (AKA KU63) does not required the halls sensors to run.

I’m concentrating on the CON62 as my controller as it is simpler without the PAS, LED sensor or need for the Halls wires. So, after a couple of days of head scratching and really understanding the 3 points above, I am getting closer to the solution. It is pretty frustrating that I can’t get this bike on the road. As I understand the wiring requirements better, I am getting closer to the solution.

The answer it takes me a couple of days to find: Looking at the red/green/black wiring on the controllers and the throttles, I notice the two throttles and the two controllers are wired differently, and that one throttle actually matches one controller (the other throttle and other controller don’t match anything). Of course, the primary throttle and controller I am using for my testing are both wired wrong, and will not work with anything.

So, after days of frustration and investigation, I finally rewire the throttle wires for the CON62 controller and the throttle I have put on the bike, and it runs! Yahoo!

So, Plug and play it is not. If I had to build another bike, I could probably do it in 30 minutes, but this took me days.
 
Thanks for the great thread.

I'm really interested in seeing the performance you get from these two bikes because I'm planning on making a dual hub motor bike with a low speed (210 rpm) motor on the back and a high speed (328) motor on the front. I want to use cute motors to keep the weight down.

What is the real "no-load" rpm (or speed) of each motor? I'd like to know how the no load speeds compare to the speeds you can actually achieve without pedaling. I'm imagining that your faster (328 rpm) motor will have a very fast top "no-load" speed, but will struggle with wind resistance when trying to go fast in the large (700c) rim. However I should be perfect for your application.

Please report back. I can't wait.
 
Beagle123 said:
Thanks for the great thread.

I'm really interested in seeing the performance you get from these two bikes because I'm planning on making a dual hub motor bike with a low speed (210 rpm) motor on the back and a high speed (328) motor on the front. I want to use cute motors to keep the weight down.

What is the real "no-load" rpm (or speed) of each motor? I'd like to know how the no load speeds compare to the speeds you can actually achieve without pedaling. I'm imagining that your faster (328 rpm) motor will have a very fast top "no-load" speed, but will struggle with wind resistance when trying to go fast in the large (700c) rim. However I should be perfect for your application.

Please report back. I can't wait.
The 201 rpm motor in a 26" wheel will give good power up to about 12mph, and then it starts to reduce. How fast you can go without pedalling depends on your weight, hills and wind. With two 201 rpm motors, your bike will be able to maintain 15mph even up slight hills. I have a 2WD bike with 328 rpm in the back and 201 rpm in the front. It'll hold 15mph in most circumstances, even up a 5% hill, but in favourable conditions, the higher speed motor will take you past 25mph. Once past about 17mph, the slow speed motor is making no contribution, so the overall speed is very dependent on conditions and weight. a 5% hill will have you straight back to 15mph (unless you're light).

With 2WD, you need a battery capable of at least 30 amps. The high-speed motor will be drawing 15 amps most of the time, so it'll get hot if abused, and so will it's controller. It's best not to use it up steep hills for too long.
 
D8veh and mototech have done that, and have some good info, so do a search and there is lots to read.

The 201 motor on a 26" goes about 15 on its own, and is happy dong 17 peddling (and probably supplying half the work). The 328rpm I plan on running mostly above 15mph. I'm in good shape, so 15mph for me is idling, 20mph is a good cruising speed I can hold 25mph if I really want to, but that takes a lot of huffing, puffing, and sweat. So I generally pedal around 21 on the road bike. When I add the motor to it, I'm thinking (hoping) it will be a good complement to me in the 15-25mph range.

FYI, a 26" tire and 700c tire are basically the same diameter if you are using standard sizes like 2.125" and 25mm respectively. Obviously you can make a 26" tire smaller (down to 1") and a 700c tire bigger if your frame will take it. Pedaling these two bikes, the slick 700c (28mm) is about 5mph faster than the knobby 26" tire.
 
Got the 320 in the 700c wheel last night. Here are my initial impressons:

While the 210 motor goes slower than I normally pedal, The 320rpm motor feels like a different beast. The slow motor is lazy and relaxed, like riding a 2 wheeled golf cart. The 320 motor is a speed demon. It likes to go 25mph where the slow motor likes to go 16mph. Big difference. I think for many people something in the middle would be nice, but Cute doesn't offer that. I did see a little Bafang on GreenBikeKit that was 260rpm. That might be nice for some people.

While my initial impression is that the 320 motor fits very nice on a 700c wheel, with the important caveats:
  • Only use the motor above 15mph
  • no sustained hills
  • rider willing to help out with the pedaling to sustain 20-25mph pace

The 320rpm has a no load speed of 30mph (just like http://www.ebikes.ca/simulator/ says), probably would do 20mph by itself, but responds very well to user input to add 5mph or more.

I need some more seat time, but the 320 motor looks to be a nice solution for a fast rider who is willing to do some good pedaling.

Attached thumbnail shows the 201 motor riding at 15-18mph (this morning's commute), and the 320 motor (road bike) riding at 25mph (both with pedal assist):

ebike commute 201.jpg
320 25mph crop .jpg
 
Went for a nice 25 mile ride yesterday at 25mph. It was a good workout like most of my rides, but the difference is that my speed was 5mph faster than normal. That was my target and it worked. Looks like I used 40-50% of a 36v10Ah battery.

Riding the bike with the 328rpm motor is like riding a tandem with a very strong rider, riding in a paceline with very strong riders, or riding down wind. Its a lot faster than I usually ride. And yes, it was a good workout too. The motor by itself will probably do 20mph, but with some good input from the rider, 25mph is a good speed (no load speed is 30mph). Certainly the motor boggs down and is not very happy below 10mph, but from 15-25mph it really shines on a road bike.

As much as I was dissapointed with the standard 36V 250 watt hub motor (which at 200rpm and a max of 18mph, isn't giving me much boost), the 320rpm version is just a blast to ride. With a small 14amp controller, it is a nice complement to my legs. It boosts my normal road bike speed of 20mph up to 25mph. If this is what the Specialized Turbo is like, that must be a fun bike. Of course my custom Specialized turbo is more than $6,000 cheaper and weighs 20lbs less. But the specifications are pretty similar. The difference is that my build isn't a hill climber and really should not be used below 10-15mph. But as a higher speed cruising motor, it is a nice complement to a pair of legs. Its not for everyone though.
 
Oh yeah, the single speed 120mm frame worked fine. I just got a bearing (1/2" ID 3/4" OD) from the hardware store to replace one of the spacers that comes with the Q100. Chainline with a freewheel fit naturally. Really though, with a 120mm frame size, you can easily squeeze a 135mm in there (the Q100 is probably closer to 130mm anyway, maybe 125 if you don't need to use the nut on the axle)
 
Great report chas. I'm really getting a good understanding of what these motors can do now. I think you found an excellent way to use the 328 RMP cute motor, but it seems to me that most users would do best with the slower RPM version.

For me, I learned that I can't rely on it as a solo high speed motor to achieve 25+ mph alone. I will need a bigger motor with more watts.
 
great motor.... for a 120mm opening, you may need to massage it a little, but it will fit.
 
migueralliart said:
So does this mean one can buy one of these motors for a rear 120mm spacing and it'll fit?

I was thinking lightweight single speed for my next endeavor.

Yep, see my post here:
http://endless-sphere.com/forums/viewtopic.php?f=3&t=48848


Works well with 42x16 gearing and a 201rpm motor on a 26" wheel and 16 mph.
Note, you can't go smaller than 16t on the single speed freewheel, so for speeds more than that you will need a good sized chainring.

I am still tweaking, but currently I have it with a 46x16 gear. At 25mph, that is about 120rpm on my legs. Good practice for me at high RPM cadence (which I need for racing).

nice chainline running as a single speed (note, this has the "bearing" from the hardware store that I used to replace one of the spacers that came on the motor, but the wheel fit fine in the dropout just stock out of the box (had to spread the fork about 10mm) with a good chainline either way.
chainline.jpg
 
Beagle123 said:
Great report chas. I'm really getting a good understanding of what these motors can do now. I think you found an excellent way to use the 328 RMP cute motor, but it seems to me that most users would do best with the slower RPM version.

For me, I learned that I can't rely on it as a solo high speed motor to achieve 25+ mph alone. I will need a bigger motor with more watts.

Yep, you are right.

In this application (700c wheel), it really bogs down and is unhappy below 10mph. But for me personally getting up to 10-15mph is a piece of cake on this bike (it is light and stiff). That will not be the priority for everyone.

This 328rpm motor really shines from 15-25mph, while the 201rpm motor is happy from 0-17mph.

Bafang makes 250rpm versions of the SWX series motor. With the ability to do 20mph, that would be a good compromise between the Q100 at 201rpm, and 328rpm. The other option is to run a 36v 201rpm Q100 motor at 48v to give 260rpm (~20mph loaded)
(or running a 24v 201rpm Q100 will give you 300rpm unloaded)

Or for both speed and torque, get a bigger heavier higher wattage (higher amp) motor.
 
chas58 said:
Bafang makes 250rpm versions of the SWX series motor. With the ability to do 20mph, that would be a good compromise between the Q100 at 201rpm, and 328rpm. ... Or for both speed and torque, get a bigger heavier higher wattage (higher amp) motor.

I have the Bafang SWXK (front purchased from greenbikekit) and SWXH (rear purchased from elifebikes). So far I have only installed the SWXK (on my wife'ss bike) and ridden the SWXK. They have the same no-load speed and are similarly sized so I assume the will perform similarly. Both weigh 2.9 kg, and both give 27 mph no-load speed in a 700c wheel with 12s lipo near the top of charge, ie 49.5 volts. In actual use the SWXK is quite strong. I'm using it sensorless with the small greenbikekit controller and the shunt soldered to up the amps a bit. With 12s lipo at 20 amps, I can take a 9% grade at 12 mph and I'm over 250 lbs. It gives a bit above 21 mph with no pedaling and about 24 mph with moderate pedaling. Under load it is a bit growly, but at cruising speed it is almost imperceptible. We have seen no signs of overheating, but it has been under 70 f here so far this year.
 
Back from my hiatus…

Things are finally coming together nicely after all this research and work.

The road bike is just wonderful, but the mountain bike was kind of pathetic. Given that 15mph is a casual walking pace for me, using a motor that pulls to 15mph, and has a no load speed of 18mph is just adding dead weight to my bike.

However, that is not really a surprise though. Just doing the math shows something similar. The 201 rpm motor was originally targeted for a 12s lipo battery which is proven to do ~20mph.

Then I had the brainstorm. Instead, why not try using the 201rpm 24v at 36 volts? That should give me a no load speed of 27mph (300rpm) and fit my needs pretty close. So instead of getting a lipo battery pack, I ordered up the 201rpm 24v hub, and just swapped out the core of the 201rpm36v wheel.

Of course, this is what d8veh suggested many months ago in the first place. :-O

Results: very nice. It’s just what I am looking for!

Tested motor speeds at no load:
210 = 18mph no load; 15mph loaded
201 24v = 28.3 mph noload; 20mph loaded
328 = 29.0 mph noload; 20mph loaded.

Interestingly the 328rpm36v motor has almost identical performance characteristics to the 201rpm24v motor running with 36v.

Both of these last two motors pull to 20mph on their own, have peak power at at 23/24mph, and are still doing 300W at 25/26mph. Since they are still pulling strong at 26mph, that gives me incentive to pedal and make up the 5mph difference.

As for overheating, the 201rpm 36v motor (noload speed 18mph) begins to run into risk of overheating below 7.5mph, while the 328rpm 36v motor begins to run the risk of overheating below 12mph. So, a torquey hill climber this is not.

Bottom line – since I like to pedal and have a relatively flat commute, I can cruise at 25mph. With 14amps, these motors are pretty low on torque, but they do roughly double the power output of my legs. All of that in a pair of bikes that weigh about 24lbs (not including battery). Makes for a nice pedal assist rapid commuter.
 
Problem #4 Crappy Chinese wheel builds – D8veh warned me of this…

The China wheel is really a crappy build. I noticed some spokes were loose, but because of the heavy gauge of the spokes, none of my spoke tools worked. I kept riding the bike, but unfortunately most of the spokes unthreaded making the wheel unusable. @#$%$

A couple of hours after this happened, my LBS called and said my spoke wrench was in, so I was able to redo all of the spokes, and also dish the wheel. The original Chinese build was undished, making the tire almost touch the frame (and requiring the brakes to be realigned).

Now the wheel is dished, centered, and properly centered in the frame.

Obviously none of this was an issue on the wheel I had built locally.

Moral of the story:

Chinese parts are inexpensive, but shipping a full built wheel costs a fortune. Its just not worth it for a crappy build. For any future wheel builds, I will just order the motor, and use the $$$ saved with shipping to build the wheel locally. That way I can get any wheel I want, and support local businesses.
 
chas58 said:
For any future wheel builds, I will just order the motor, and use the $$$ saved with shipping to build the wheel locally. That way I can get any wheel I want, and support local businesses.
Or just build it yourself. Wheel building is pretty easy and only takes a hour or so once you've done one. See Sheldon Browns instructions. I like Edd for figuring the length of spokes to order and Danscomp for ordering spokes.
 
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