Carbon Cyclocross Drop Bar Commuter Q100C

[MonkeyWrench]

My latest build, a carbon frame Foundry Harrow with a fast wind Cute Q100C:





Backstory
After many great miles commuting on my 9C DD mountain bike, I was ready for a change of pace. My ebike experience had actually gotten me started into the world of road cycling and I had been trading off between the ebike and the regular road bike for my commutes. I've been riding the DD mountain conversion ebike for about 6,000 miles since 2014 and the road bike for about 4,500 miles since 2016.

In September 2017 we moved to a new place about 16 miles from work which doubled my commute. Gave me the excuse to put together another build based on the great little Q100 "Cute" motor as seen on some great builds on ES.

My goals for the build:

• Drop bars

• Lightweight

• Keep it more of an assist, so minimal impact to pedaling

• Disc brakes to cope with winter slop

• Large tires (for a road bike anyway!)

• Speed enough to supplement my already fairly high cruising speeds

I found a nice Foundry Harrow cyclocross bike on Craigslist. This bike checked all the boxes and has been a real pleasure to ride. Did my first century (100 mile) organized ride on it last summer pre-electrification. The carbon frame, fork, and 32 mm tires add up to the roadie equivalent to downright cushy

I was pretty torn on which wind to pick for the Q100. I had read cautions that the 328 RPM wind in a 700c wheel would be trouble. But, I also saw some encouraging folks such as Kepler and chas58 relate that the high speed wind works well if you use as an assist. I didn't want to get stuck with a bike that was too slow! I was used to my ~30 MPH mountain conversion. Took the chance and bought the 328 RPM option from BMS battery. Laced it into a Velocity wheel with some bladed spokes to kinda match the Mavic Ksyrium front wheel. Used my spare 6FET controller from em3ev. For now I've been running x2 leftover 6s 5 Ahr Turnigy lico/lipo (12s @ 5 Ahr = 222 Whr nominal). This has been just fine for my commute with charging at home & work, although I have an 18650 pack build planned to shed another pound while increasing range.

Cycling Experience
The bike works absolutely fantastic! If you are a regular cycle commuter or road cyclist and are already used to gutting out the hills on just leg power you will probably be fine with the 328 RPM motor in the 700c wheel size. The slower wind would have been tapped out at a slower speed than I like to occasionally sprint up to. I was actually pleasantly surprised with the how much torque the little Cute has, I expected it to be absolutely gutless on acceleration but doesn't seem so. Using low sag lipo probably helps somewhat. Obviously not a 3 kW DD but I'm feeding it about 900 W peak and it does great for what I want out of it. The key, as always, is to keep the average power consumption within the thermal limits of the motor. Even with my now customary 25-30 MPH sprint the last few miles to home I've only felt the motor get slightly warm.

I ride it very much as an assist overlaid onto my normal effort. It helps tremendously getting back up to cruising speed after the many stop/starts on my route. Most importantly, it gives me a decent workout while peak shaving the real heavy effort stuff, and keeps my average speed up higher than I can manage on the regular road bike. I highly recommend a build like this (or any ebike, really) for those potential road bike convert folks out there- ride your ebike on your recovery days, or those times you would otherwise get in the car.

It pedals just fine with motor off. A couple weeks ago a friend and I went on a 30 mile ride before work, he was on his regular road bike. I used about 15 Whr showing off up a hill, other than that didn't use the juice at all. No problem. Obviously you can notice the +9 lb and just a bit more freewheel drag, but that small amount doesn't discourage riding it unpowered.

Personally, my preference is to NOT use PAS for a build like this. I'm constantly on & off the "throttle" blending in just the right amount of assist. I drive myself nuts trying to button push a PAS unit to match what I want from the motor (I've tried). With the bike being so darn efficient when the motor is off means more fluctuation in desired assist compared to a build like my DD mountain bike where I am on the throttle just about 100%.

Performance/Efficiency
Although I expected the drop bar bike to be efficient, this build has done better than I hoped. After about 700 miles on the build I'm seeing about 7 Whr/mile on average consumption, with my average speed over the commute being ~18+ MPH. For comparison my 60+ lb DD mountain bike on 2.2" tires was consuming about 22 Whr/mile with average speed of approximately 22 MPH (lots of stop/start).

With the fast wind at this voltage level the bike easily breaks 30 MPH sprinting with just the right cadence in top gear. Obviously I don't cruise at that speed with average consumption so low. My normal unpowered cruise on the flat of 18-20 MPH turns into 22-25 MPH on this bike.

My baseline commute is just over an hour for the 16 miles on the regular road bike, the e-cyclocross bike shown here cuts that to 50-55 minutes. My higher power direct drive motor mountain bike is 40-45 minutes. Given the current state of Seattle traffic, the ebike wins over caging it for sure on peak hours! Not to mention riding is way more fun, great exercise, and cheaper. Last summer I saw significantly more regular ebike commuters and I only see that trend increasing.

Build List & Links

To sum up the build list, to help those new folks out there:

Bike: Foundry Harrow cyclocross. Disc brakes, clearance for larger tires http://foundrycycles.com/archive/harrow

Tires: Continental Gatorskin 32mm width

Motor: Q100C. 328 RPM, cassette version. BMS battery- https://bmsbattery.com/ebike-kit/651-q100c-cst-36v350w-32-hole-rear-driving-hub-motor-ebike-kit.html

Contoller: 6FET from em3ev, 3077 FETs programmable parameters- https://em3ev.com/shop/6-fet-irfb3077-infineon-controller/?currency=USD (using a thumb throttle with PVC standoff trick others on ES have posted on)

Batteries: x2 6s 5 Ahr Turnigy lico/lipo (good ol standby)- https://hobbyking.com/en_us/turnigy-5000mah-6s-20c-lipo-pack-w-xt-90.html (NOTE- there are better lipo options out there for low power builds- see Turnigy Multistar, I just had these on the shelf)

Packaging: Novara underseat bag rescued from the used bin at the bike shop. Fits the x2 Turnigy lipo and the little 6 FET controller. So far it has been ridden only in winter, will have to monitor controller temps in summertime.

Wheel: Velocity Aerohead, can get them to match the higher spoke counts, with/without rim brakes, good value- http://www.velocityusa.com/product/rims/aerohead-622

Spokes: Sapim CX Sprint, bladed, J-hook, custom lengths- https://www.probikesupply.com/products/sapim-cx-sprint-black-j-bend-spoke-individual (I only chose bladed to match the front Mavic. Normally I like double butted 13/14/13 gauge Sapims which are cheaper)

Brakes: Avid BB7 mechanical road discs. Had to go up a size in the rear to clear the hub with the inboard caliper mount. Machined some caliper spacers on the lathe, but could probably find something equivalent at the hardware store.

My fav spoke calculator: https://www.prowheelbuilder.com/spokelengthcalculator/

Future mods: 18650 battery build, slimmer thumb throttle/button arrangement, carbon battery compartment in front of seat tube. Throw the knobby cyclocross tires back on and get it muddy...?

 

[SlowCo]

Beautiful ebike! 8)
Reading how you use the throttle to let the motor only assist you it might be an upgrade in the future to exchange the controller to a Grin Phaserunner. That has true FOC with a torque instead of a speed throttle function.

 

[ModeratelyFastF]

Awesome bike and post, very helpful and inspiring! Looks like you more than met your design goals.

As you know I'm looking at doing a very similar build. One question that may fit here best: what do you think the likely pros and cons are of going with the q128c, all else being equal (ie same rpm)?

Also curious about noise, can you hear it under normal conditions (I've heard the q128c is particularly quiet)?

Great work again, I hope my build is as successful!

 

[zro-1]

Very nice bike and build! It's nice to see other new light-weight road bike builds popping up. I have to second the Phaserunner recommendation. I've got the Phaserunner and a 328 RPM Q100H on my bike right now, and it sounds like you and I ride our bikes in pretty much the same way. Having the FOC torque throttle from the Phaserunner is perfect for this type of use in my experience so far. I'm also hitting ~30 MPH on my build as well, but having a single speed 46/16 I can't keep up at the top speeds.

I'm looking forward to seeing what you do with the 18650 battery build.

Keep up the great work!

 

[MonkeyWrench]

Thanks guys! I appreciate the kudos. I'm very happy with it.

I hear you on the Phaserunner. It's definitely on my wish list, both for the bump in technology as well as the form factor.

It's nice to see other new light-weight road bike builds popping up.

Yes! Trying to spread the word that there is "another way" other than the typical full suspension monster bike- but those are cool too. Should just own one of each flavor to cover all the bases.

 

[zro-1]

That's what I do I've got the powerful FS MTB with the BBSHD for shenanigans and now this lightweight build for regular road use and commuting.

I meant to add that I'm also running 32 hole front and 36 hole rear spoke setups. I really like the velocity deep-v rims with machined sidewalls. I just ordered a matching front 32 hole to go with my 36 hole rear. The braking feels soooo much better on machined sidewalls vs cast and powder-coated cheapo rims. My cheapo front actually has a bulge at the seam which is super annoying and a little nerve-wracking when trying to stop quick at higher speeds.

 

[MonkeyWrench]

Those Deep-Vs are sweet. I almost broke down and ordered a set for this build but that Mavic on the front was too nice to sideline.

A well set up rim brake setup with quality hardware is hard to beat. When I swap out onto my friend's ride with Ultegra brakes I'm always a bit startled at how much authority they have.

Commuting year round in Seattle led me to the discs. Keeping a rim brake clean in the winter slop requires daily rinsing with the hose and frequent actual cleaning and wipe down. Even so, the road grit means a set of pads gets chewed up over a few months!

I have Avid BB7 mechanical road discs on this bike. Although they don't have the initial whoa pony bite the Ultegra rim brakes have, they are more progressive feeling and will get to tire skidding braking force if you put enough squeeze on.

I went for the 32 hole Q100C just because it was available and matched the cyclocross wheel set pretty closely. BMS battery has the 32H option.

 

[zro-1]

In my opinion disk brakes will always be better than rim brakes—both for feel and stopping power. Maybe sometime in the future I'll change out my front fork and hub to get a disk up front, but for our style ebikes, I think good rim brakes are probably enough. You're lucky you've got the disks already.

I also meant to complement you on your first post on this thread. I really liked how you broke down the intro into the sections you did. I may go back and do something similar in my build thread once the bike is complete.

 

[ScooterMan101]

MonkeyWrench,

Good Conversion.

Please post some pictures and diagram of how you connected the Hall Sensor and Phase wires of the controller and motor together . ( What color at the Motor to what color at the controller )
You are now the only the second person I have read that has used a " Infineon " controller with the little Q100 motor. The first stopped posting right after finishing his conversion.

For a little background since, I have not posted a build of my Aluminium Road/Gravel bike ...
I built mine from the frame up , and always having a low budget to work with I went with a flat mountain bar and mountain BB7 brakes .
I do now have the dropbar and shifters, but the flat bar setup works so well with a throttle that I have not yet put them on.
Being Aluminum and using 29 er disc wheels , my bike was at least 2 pounds heavier to begin with compared to yours. I also use 32 mm wide tires.

I have the 201 rpm Q100c motor since I bought the motor from someone that was a little less than 100 miles away from me, and all he had left was a 201 rpm version with 36 spoke hole flange.
I probably ride half the speed as you when not using the motor, 8-9 mph average on any ride on the road bike.
So with the slower wind motor and weak legs and middle age Cardiovascular System, I can only get the bike up to 20-22 mph on the flats with no head wind ... and that is when using a 14s lipo pack ! ( I live in a area with many very serious Road Bike Riders that regularly ride up to 28-30 mph when in a group so I am always left behind )
You are the first to say you are putting up to 900 watts through the little Q100c ( c meaning the cassette version )
The person I bought the Q100c cst from was going to only use the H versions in the future because they are said to be able to handle more watts, and he was even going to make a complete bike using the Q128 because it would handle even more.
So
It is good to hear that little Q100c is holding up at 900 watts , as I only get up to around 650 watts through mine when going up hills.
I have a 9 fet / up to 72 volt " Infineon " controller from Em3ev.com just sitting unused in a box, and for a while I was thinking about putting it on the bike, however the wires would have to be correctly matched with the motor and controller. ( So My interest in how you wired it up correctly ) some other E.S. members that use the same motor , say there would be inefficiencies with higher voltages through that motor , so I have shelved that Idea for now. ( was thinking about a 16s pack ) So I am Even thinking about selling the Motor/controller/display since I want to go faster , and have reached the limit with that motor on a 700c/29er wheel and 14s pack .
For most people in the world the 201 rpm would be fine ... but I live in a area with many , very serious Rodie's .

 

[MonkeyWrench]

Hi ScooterMan101-

Regarding phase and Hall connections- I've been lucky. It was a direct color match between the 6FET em3ev controller and the Q100C from BMS Battery. I also had a direct color match between the 6FET em3ev controller and a 260 RPM SWXH from elifebike aka PSWpower. The color matched for both the phase connections as well as the Hall sensor connections.

Hopefully you will have the same luck with the connections, if not there are many good threads on ES that can help troubleshoot.

I hear you regarding the experience with the slower wind. Undoubtedly better up hills when you get bogged down but can't keep up the pace on the flats. I don't have experience overvolting the little motors and defer to the other ESers on the outcome of that.

Bear in mind that I pedal 100% of the time, usually at or near my personal peak output. The fast wind Q100C is more of a supplement rather than a base propulsion power source. It helps me push my average cruising speeds up and commute time down while still getting a heart pumping, sweat when it's 35F out, kind of workout.

So, while I am able to pull peaks of ~900W that is definitely more of a burst power level. I am not sure how well the Q100C would do for extended high power runs without serious pedal input. Here is an example of probably the highest speed longest duration "duty cycle" cruise power level I have ridden to date:



As you can see there is a fairly long (6 mile or so) segment where I am averaging a pretty decent speed. This is all while I'm pedaling pretty hard and using the motor to keep the speed up. I am probably putting in 150-200W leg power. I'm also not at 100% throttle unless I want to boost up to the 30+ mph range. So, going back to the simulator, assuming 85% throttle setting and 150W of leg power puts the bike at about 27 mph. This scenario sees about 500W power into the controller/motor, which is operating at 77% efficiency. This means 385W actually get put to the ground and the motor needs to dissipate only 115W. The little Q100C has no problem dissipating that kind of waste heat in my experience. I've actually noted my controller warming up (still not "hot") while the Q100 remains cool on my rides.



It all comes down to where you are operating on the efficiency curve and how much power you are feeding it versus the ability to reject the heat to ambient. The wasted power generates heat, and if that rate of heating exceeds the motor's ability to shed it to ambient you will see continued heat rise until it melts down. Pretend there is a space heater of XX Watts inside that tiny motor casing and you get the idea.

This is why, as many others have found, when you operate the motor well below it's peak efficiency point (say, up a long steep hill) and continue to feed it high power it can take only a matter of minutes to drastically overheat. But, if you save the high power level for closer to the peak efficiency point of the motor (aka higher road speeds) it can tolerate much longer bursts, up to steady state operation. You can see this effect in the simulator by either adjusting the percent grade upwards (keeping throttle at 100%) or by manually dragging the speed bar down while keeping 100% throttle which simulates acceleration. You can see how the efficiency drops and just how much more of that power gets converted into heat which must be dissipated.

One really great tool with the Infineon style controllers is the 3 speed switch input. With the em3ev controller you can tweak the programmed settings of what % throttle each speed is set to (need the program cable). That way, you can find the right cruise speed for the motor that matches the power level you want to provide with your legs, and that won't result in too high of motor temps for the routes you are riding. So, if you find that the Q100C fast wind is heating up too much try dialing back the max speed % until you find a good operating point for both you and the power system.

Then you'll be able to smoke those mere human roadies! Or they'll buddy up to you and put you at the head of the pace line.

PS- is your sig based on some Nightwish lyrics? Got to see them in concert once, good stuff.

 

[ScooterMan101]

MonkeyWrench,

Yes the text in my sig is based on a Nightwish song .
We have had many days of rain lately and I was frustrated about not riding much , so had just recently put that on my sig. Looks like starting Wednesday we are going into spring weather so I will be taking that off my Sig soon.
I come from the Rock and Roll and Heavy Metal Band ... generation,
However
I just this month found out about Nightwish.
Another song, Ghost Love Score performed at the Wacken Open Air 2013 is probably up there in the top 10 or 20 top Rock and Roll songs of all time.
How could I not have heard of them before ? They are one of the Best Rock/Metal Bands Ever !
I live in the U.S. that is why I did not know of them, never once heard them on the Radio , nor Paramore either for that matter.
It is only by listening to a song on youtube, then seeing other songs/artists on the right side of the page that I find out about Bands like those . even Within Temptation, I found out about them by typing in on youtube ... Isle of Man TT , a great video to see what the Isle of Man TT race looks like with the song faster added.

Regarding putting more volts into the little Q100c motor , I do not think I will be doing this I am already at a 14s pack and from getting just a couple of mph from using 12s pack with it and then using a 14s pack the difference between the 14s and 16s pack I think will still not get me up to speed enough. I only got a few Mph going from 12s to 14s .
I will save that 9 fet controller for another project.

Right now I am waiting for others to develop the little RC motors for use on a bicycle, there are a number of people working on that now , but none yet writting about using the little R.C. motor to the crankset on a road bike, just Large Wattage and Amperage Downhill , and custom E-Bike frame bikes at the present time.
Luna had a picture of what I am talking about somewhere but I think they took it down, it had a little R.C. motor driving the crankset on what looks like a copy of the Specialized Venge Vias Road Bike.
There is a article of a retired man in Switzerland many years ago that did this with his Scott Carbon Mountain bike, but much to my surprise and frustration, no one has yet to do this on a light weight bike , I think this will be the right drive for many of us in the Future , since it is an even lighter weight system than the little Q100c and it uses the bicycles gears so is better than a friction drive for someone like me who likes to ride in the surrounding hills.
I plan on selling my Q100c motor/controller/display once a good RC Mid-Drive for Road Bikes / Light MTB's is developed.

 

[zro-1]

Luna had a picture of what I am talking about somewhere but I think they took it down, it had a little R.C. motor driving the crankset on what looks like a copy of the Specialized Venge Vias Road Bike.
There is a article of a retired man in Switzerland many years ago that did this with his Scott Carbon Mountain bike, but much to my surprise and frustration, no one has yet to do this on a light weight bike , I think this will be the right drive for many of us in the Future , since it is an even lighter weight system than the little Q100c and it uses the bicycles gears so is better than a friction drive for someone like me who likes to ride in the surrounding hills.

Is this the article you were referring to ScooterMan? https://www.electricbike.com/lightest-bike/

 

[ScooterMan101]

Yes that is the latest article on him and his bike, that one was done in 2012.

I saw an article about his bike before that one, it was also very light and had the same drive system , a little RC Hobby motor direct to the crankset, and it looks like he does not even have a freewheel on the crankset ?

The first time I saw an article about his previous bike was about 10 years ago.

And yet we still do not have the answers as to which motor , what kv on the motor, what voltage battery pack, etc.

And even worse , we do not even have a system that we can buy to do that to a light weight Road Bike or MTB , in over 10 years !

That man over 10 years ago is who got me interested in an E-Bike.
and it is the system I am most interested in having even now .

Luna had a picture of what I am talking about somewhere but I think they took it down, it had a little R.C. motor driving the crankset on what looks like a copy of the Specialized Venge Vias Road Bike.
There is a article of a retired man in Switzerland many years ago that did this with his Scott Carbon Mountain bike, but much to my surprise and frustration, no one has yet to do this on a light weight bike , I think this will be the right drive for many of us in the Future , since it is an even lighter weight system than the little Q100c and it uses the bicycles gears so is better than a friction drive for someone like me who likes to ride in the surrounding hills.

Is this the article you were referring to ScooterMan? https://www.electricbike.com/lightest-bike/

 

[calsurfer]

Hey Monkeywrench,
This is a great looking bike and build, it has inspired me! Looking to convert my old carbon cross bike myself. Started a separate thread for that - but have a few basic questions:

Any issues with the carbon frame and the q100? Seems like a low enough power motor that it would not be an issue, but I wanted to check if you were using any torque arms?

I had some feedback that I may need to file down the dropouts to get the motor to fit, which would create an issue converting back to a regular bike. Back in my cx racing days, we would file down the dropouts anyway, for quick tire changes. Wasn't sure if the type of modification required was more than that.

Last question is the controller. The controller you purchased looks perfect, except its on backorder! They sell cheaper controllers on BMS, and then there is the phaserunner...but neither of these seem right for me. I want something simple, but slightly programmable, that rides great.

thanks!

 

[ScooterMan101]

Torque arms on a Carbon Frame is a very good idea even with a low torque motor, put some thick rubber between the steel torque arm and the carbon so as to not rub a hole in the carbon.