Cute Q100 lightweight builds slow mtb, fast road

[majornelson]

Chas,

Great build thread. I'm looking to build something similar (but slightly heavier frame). My commute is only a couple of miles and is mostly neighborhood roads.

Still happy with the result? Also, what battery did you buy?

Thx!

 

[chas58]

Yep, it works great.

The 201rpm24v motor at 36volts (300rpm) on the mountain bike works well for me for a flat commute. It pulls to 20mph by itself, and is is happy running at 23mph (average cruising speed) with plenty of pedal assist.

I got a 10ah36v LiFePo4 battery, in the aluminum box with keyed on/off switch. It is a bit heavier than advertised at 10 lbs. A basic lithium-ion battery would be about half that weight. I basically ride it like I ride a normal bike with a higher top speed (22 - 25mph). It has a range of 24-25 miles (again with me providing about half the power).

Battery:
http://www.greenbikekit.com/index.php/36v10ah-lifepo4-ebike-rack-battery.html

Bought within the following kit:
http://www.greenbikekit.com/index.php/36v-250w-gbk-100f-front-driving-e-bike-kit-36v-10ah-lifepo4-battery.html

 

[adamred23]

Does the 201rpm motor give more grunt at lowers speeds at 24v vs 36v, or does upping the voltage just allow the motor to pull into higher speeds? If it did pull harder at 24v at the lower speeds, I may look at setting up a dual controller configuration to use the 24v201rpm motor at 24v at lower speeds, then switching to 36v at higher speeds.

 

[majornelson]

Adamred23,

I'm curious about the low end torque also. Where I am a little confused is the difference between a 24v motor running at 36v vs. a 36v motor running at 48v. I understand by upping the voltage on either I should see higher RPMs... Intuitively, I think that the 48v system may pull harder but I have to be careful not to fry the little motor with more amps.

So I have both a small Bafang (K5) and the Q100, both running at 36v and I have a 48v RC Lipo setup I plan to test them with. I looking for a light duty (read less than 5 miles round trip commute, relatively flat) commuter and city bike. I'll be putting it on a Brooklyn Cruiser 7 speed. Sometime late August...

I hope I'm not disappointed... (I've been spoiled running a 500w 8T Mac with a cell_man 48v 18.5 AH triangle battery. Great speed, range, handling... it just weighs a lot.)

 

[d8veh]

Running at a higher voltage has a similar effect as a proportional increase in the current. The height of each PWM pulse is higher, so more energy is transmitted into the motor with each pulse. When you increase current, the width of the pulses increase. Whether you increase the width or height, the effect is similar, although in practice it's not quite as simple as that, and each has advantages in different circumstances.The Q100 is designed to run on 24v or 36v and it's rated at 350w continuous. If you use a standard 15 amp control, it rough works like this at its rated current of 8 amps:
24v x 8 amps = 200w
36v x 8 amps = 300w
48v x 8 amps = 400w

In practical terms, the voltage is the best way to get the good efficiency from the motor by running at a speed closest to what you ride considering the power it'll be producing.

 

[chas58]

It is interesting to compare these two bikes and these two motors. The clear winner for me (a strong rider in flat terrain) is the 24v201rpm Q100 build running at 36V 300rpm.

The 36V328rpm motor is good on a road bike, but it does growl at low speeds (<10mph). It does seem to have more torque and more “kick” when it engages at moderate speeds. On a fast road bike it makes a fun combination.
The 24v201rpm motor at 300rpm is a lot smoother and quieter. It seems much more flexible and useable, even if it doesn’t seem to have the kick (torque) of the 36v328 motor.

My goal with E-assist was to have 50% power input from me, 50% power input from the motor, and an increase of 5mph top speed of both bikes. That is pretty much what I have ended up with:

Average Cruising speed in MPH:
MTB-P 17.5 (pedal only)
Road-P 20.5 (pedal only)
MTB-e 23 (Max ~25) (e-assist)
Road-P 25 (Max ~28) (e-assist)

The other little surprise is range. For my average commute, the MTB at 23mph has a range of about 24 miles. The road bike at 25mph has a range of 32 miles. The road bike has 33% longer range than the mountain bike. Both bikes are fairly stiff and fast bikes that weigh about 24lbs without battery. Obviously the road bike is a lot more efficient in pedal only or e-assist mode.

 

[majornelson]

What are you using for your battery and how many Amp Hours?

I'm fascinated by the Q100. It is stealthy and doesn't weigh that much. I just finished a new build with a Q100 201 rpm motor on a steel cruiser style bike. Running 5 AH of 44v Lipo (which charges to 49v - not certain why it's listed at 44v (22v x 2) ). Commute to my work which is only a 5 mile round trip.

My build started at about 41 lbs (bike + Brooks B67 + wood crate) and is now around 52 lbs. Feels lighter than it sounds. PAS only... Does around 18 mph on the flats tops. Wants to go a little slower but I can get about 20 miles out of the 5 AH with a little pedaling. My goal is not to sweat on the way to work in slacks...

Some pictures and comments here (scroll halfway down for pictures):

http://endless-sphere.com/forums/viewtopic.php?f=6&t=52559&p=794208

Both you and d8veh were inspirations for my recent build! It's great to see what others are doing to push it.

 

[chas58]

Your bike looks beautiful! You have a nice set up there!

The Q100s are great if you like to pedal and don’t need the motor’s help much to climb a steep hill. It is very stealthy and light (but no torque monster).

I bought a 201rpm with the intention of going lipo, but stayed 36v for size and lightness. The lightness ease of use a 36v Lithium-Nickel-Manganese-Cobalt-Oxide, or LiNiMnCoO2/NMC is my current favorite. I haven’t bought it yet, as I am using a 36v10AH LiFePo4 battery. Works fine, just weighs a ridiculous 10lbs (that is almost half the bike weight without battery).

 

[fa001313]

I'm a bit in the same boat. Going to convert my 700c CX bike (21lbs) and i in doubt wether to use the 36v-328rpm version or the 201rpm-24V version and run it on 36V.
I mainly ride on relatively flat roads but i'd like to be able to do an occasional cross track.

Wich motor would you prefer and is there a hug difference in torque between the two motors (in low as wel as high speed).
Great builds you have btw.

 

[chas58]

I think running the 24v 201rpm at 36volts (300rpm) is the clear winner of the two. Neither has a lot of torque. The 328rpm version growls at low rpm – I’m assuming this has something to do with the compound gearing. Its only real advantage is a bit more speed on the top end (assuming you are providing lots of input too). Neither will do above 20mph by themselves, so you have to pedal to keep them in their sweet spot. The 328 is only good for a bike that you are going to provide most of the input below 5mph, and one that spends almost all of its time in the 15-25mph range (80% of the time above 20mph). That is most of my riding and it does well with that.

For most bikes, getting that one or two MPH of top end isn’t worth it for the 328rpm version.

A cross bike would be great for this type of setup!

 

[majornelson]

I have the 36v version and a 44v lipo (2 6S lipo in series) battery setup. Any guess as to how this differs from your 24v / 36v battery setup? My thought is lower top end but a little more torque... I'm really not certain, though.

 

[d8veh]

I have the 36v version and a 44v lipo (2 6S lipo in series) battery setup. Any guess as to how this differs from your 24v / 36v battery setup? My thought is lower top end but a little more torque... I'm really not certain, though.

A lot more torque and less top speed. For me, this is the best combination, because the motor has the power to work on its own and it's still relatively efficient through most of its range. Pedaling helps, but isn't so as essential as it is with the 328 rpm version. The 24v 201 rpm version also works very well with 12S.

 

[meelis11]

Very useful information in this thread! Thanks
Although I bought GNG mid drive and are really happy about its power and torque, I am still liking these small hubs. I want to try one of these
That is probably best thing if someone wants to make stealth lightweight ebike that average Joe does not know it is bike with steroids

Meelis

 

[chas58]

Yeah, it looks a lot like an internal geared hub, where the gears are used for shifting, not like an internal geared e-bike hub.

A 36v 15amp Q100 doesn't have lots of torque (whichever winding you use). More power = more torque. Increasing the voltage is one way to do this, and a popular way is to increase the current by soldering the shunt as d8veh has explained in the past.

 

[d8veh]

My neighbour has a bike with a low-speed Bafang SWX in the front, and he wanted a bit more speed, so he put the 328rpm Q100 in the back as well. This bike goes really well with the Bafang providing most of the power up to 15mh, and then the Q100 takes over. I think that you could make a nice light-weight bike with a 201 rpm Q75 in the front and the cassette version Q100 in the rear. You only need one battery (capable of 30 amps), but you need two throttles. You can use a Cycle Analyst to split the throttle signal or make a double throttle, or even use two throttles.

 

[chas58]

So, you would essentially have two motors below 17mph, and just the high speed motor pulling above 17mph.

 

[Cephalotus]

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.

Nice bikes. I like the approach...

I have my summer-city-pedelec wich is inexpensive and lightweight (14-15kg incl. rack, fenders, lights, motor) has three option for the front wheel:

- not motor
- cute 85 201rpm
- cute 85 328 rpm

For legal reasons I use mostly the Cute 85 201rpm which is fast enough for 25km/h+ in a 28" front wheel

I tried the 328rpm and I think that it is also usable for going uphill or accelerating (not from standstill, for legal reasons I activate the throttle only after pedaling is detected)

The Cut 85 are even less powerfull motors than the Cute 100.

The key for going uphill or at slow sppeds is to reduce(!) the max A from the controller. 10-12A @ 36V is good for egenrall use, for steep hill 6-8A @ 36V is ideal.

Of course you have to pedal with such bikes, the motor is "just assisting". But going 40km/h at 10A on the flat is no problem if you add your own pedal power.

If you wnat a motorcycle you have to use different motors of course.

My power consumption is aroudn 3-4Wh/km with the 201rpm motor and around 8-10Wh/km with the 328rpm motor. I mostly use a rather small battery with just 200Wh, but this is plenty for my everyday needs. (10s3p Sanyo UR18650E without BMS, those cells do not need balancing)

regards

 

[Cephalotus]

Futue plans:

• swap out the 36v 201rpm motor for a 24v 201 rpm motor (which will run 300rpm at 36v).
  Build a small light 2.0KG 36v8ah battery that can mount in the frame triangle

The 24V 201rpm motor is the same as the 36V 328 rpm motor. In reality the 36V 201 rpm motor has a bit more than 201rpm, more like 220rpm @ 36V.

 

[chas58]

Futue plans:

• swap out the 36v 201rpm motor for a 24v 201 rpm motor (which will run 300rpm at 36v).
  Build a small light 2.0KG 36v8ah battery that can mount in the frame triangle

The 24V 201rpm motor is the same as the 36V 328 rpm motor. In reality the 36V 201 rpm motor has a bit more than 201rpm, more like 220rpm @ 36V.

The internals are different and they perform a bit different as I noted above. I like the 24v at 36v better than the 36v 328rpm motor for most applications.

 

[majornelson]

Saw this the other day:
http://www.bmsbattery.com/48v/166-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

Basically 6.2" x 6.6" x 2.6". Really nice size for a rear rack and it comes in at 7 3/4 lbs (assuming there is truth in lending here ).

My battery consists of four 22v RC Lipo packs (12s2p - 44v and 10 Ah - no BMS) weigh in at 7 lbs... and are basically the same size.

I've been getting about 30+ miles (including pedaling) from my current pack on my front mounted Q100. If this battery does what it says, it's a nice option to RC Lipo...

 

[chrisbr]

Interesting !

I'm a road cyclist and what i want is basically a faster bike to make the longuer rides a bit more easy and fast... and to get there with a bit less of pain..sometimes . (my plan is to have basically the same bike that you have but with gears at the back...still not sure if i'm going for front or back...probably will depend on steath mode...)

The Q100 24v201rpm on a 36v lifepo4 seems a good option for what i'm looking for. On a 700c at what minimum speed do you think a I should pedal before putting the throttle ON ?(without getting the weird noise...i think your posts refer at a 26 inch one...so would it be a lot different on a 700x23?). That way it would also make a good commuter kinda bike if it could "start" before a 12mph, but no big deal anyway...and loosing a few kmh is just a good reason to push more...

Also, i would be curious to know how you fitted the throttle on your road bike, I plan to use the same type of handle bars and was wondering if a half throttle would manage to get pass that "90 degre angle" all the way to the stem.... if you have picture or infos on that, it would be great !

ps: new at ebike stuff...this forum is amazing ! learning every day !

great post !

 

[chas58]

Yes, the Li-Ion NiCoMn batteries are a bit lighter than LiFePo4.

“I've been getting about 30+ miles (including pedaling) from my current pack on my front mounted Q100. If this battery does what it says, it's a nice option to RC Lipo...”

Yes, that is what I am thinking. The tradeoff with LiFePo4 is a significant weight savings with about half the cycle life. Be careful with BMS battery though, when pressed, they have told me their 18650 batteries are 0.8 to 1.0C. That is a deal killer for me. Not sure what the C rate is on these – I would guess 1.0 (just a guess). Em3ev has some good higher C rate NiCoMn batteries. I would make the extra investment in those both for performance and for lifespan.

Saw this the other day:
http://www.bmsbattery.com/48v/166-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

Basically 6.2" x 6.6" x 2.6". Really nice size for a rear rack and it comes in at 7 3/4 lbs (assuming there is truth in lending here ).

My battery consists of four 22v RC Lipo packs (12s2p - 44v and 10 Ah - no BMS) weigh in at 7 lbs... and are basically the same size.

I've been getting about 30+ miles (including pedaling) from my current pack on my front mounted Q100. If this battery does what it says, it's a nice option to RC Lipo...

 

[chas58]

The 24v201rpm at 36v is very quiet and starts well from a stop. It is pretty silent throughout its speed range. You can use the throttle at any speed. (this is what I am using on the mountain bike)

The 36v328rmp version growls below 10mph, and sounds unhappy below 5mph.
(this is what I am using on the road bike)

A 26x2.125 tire is the same diameter as a 700x23 tire.

For the throttle on a road bike, I do not have any good solution. The best I can come up with is:
- Use a flat bar so I can use a handle bar throttle
- Use a PAS so a handlebar throttle is not needed.

Currently I have a thumb throttle tacked onto the end of the bullhorn. Its not a very elegant solution. The diameter of the bullhorn is bigger than the diameter needed for the handlebar throttles.

Interesting !

I'm a road cyclist and what i want is basically a faster bike to make the longuer rides a bit more easy and fast... and to get there with a bit less of pain..sometimes . (my plan is to have basically the same bike that you have but with gears at the back...still not sure if i'm going for front or back...probably will depend on steath mode...)

The Q100 24v201rpm on a 36v lifepo4 seems a good option for what i'm looking for. On a 700c at what minimum speed do you think a I should pedal before putting the throttle ON ?(without getting the weird noise...i think your posts refer at a 26 inch one...so would it be a lot different on a 700x23?). That way it would also make a good commuter kinda bike if it could "start" before a 12mph, but no big deal anyway...and loosing a few kmh is just a good reason to push more...

Also, i would be curious to know how you fitted the throttle on your road bike, I plan to use the same type of handle bars and was wondering if a half throttle would manage to get pass that "90 degre angle" all the way to the stem.... if you have picture or infos on that, it would be great !

ps: new at ebike stuff...this forum is amazing ! learning every day !

great post !

 

[chrisbr]

For the throttle on a road bike, I do not have any good solution. The best I can come up with is:
- Use a flat bar so I can use a handle bar throttle
- Use a PAS so a handlebar throttle is not needed.

Currently I have a thumb throttle tacked onto the end of the bullhorn. Its not a very elegant solution. The diameter of the bullhorn is bigger than the diameter needed for the handlebar throttles.

hmmmm so no real solution with an "aerobar" with brakes lever at the end....wish there was some kind of "strap-on thingny" throttle...the only one I saw was a press button, velcro thing, but would give "all out" signal...0w or 250w....not an option here...if i find something I'll come back here an post it.

No PAS for me...not now anyway

Thanks !

 

[majornelson]

the only one I saw was a press button, velcro thing, but would give "all out" signal...0w or 250w.

Do you have a link to the velcro press button? I've actually considered that for my PAS only bike. With the smaller motors, I think a button would be a nice addition to the PAS...