My second e-bike: Reality Check? (Pretty please?)

[Joe Perez]

More of a Star Trek fan myself!

[o00scorpion00o]

More of a Star Trek fan myself!

Haha

To boldly go where no man has gone before, it would take light years to get to the moon on that thing never mind travel the galaxy !

[Joe Perez]

It lives!



Still waiting on the triangle battery, but I finally got all of the mechanicals sufficiently assembled to hook up the controller to a pile of lead-acid batteries which I had lying around (I had to steal one out of the alarm system in the apartment, which I never use anyway) and perform a free-air test. Lo and behold, the motor rotates- and in the proper direction, even. Much rejoicing.

Now, on to this CycleAnalyst which has been feeling neglected for the past few weeks.

[Ykick]

Looks like a great start Joe! But, your workspace is way too tidy, IMO...

[Joe Perez]

But, your workspace is way too tidy, IMO...

I assume you're joking- the garage is an absolute mess right now.

The old Amped bottle battery died just as I'd started stripping down and painting the car, so I had to quickly wrap that up and get it back on the road (I'm presently driving a Miata that's 1/3 shiny blue and 2/3 old, faded sparkly teal), so the fallout from that job is sort of scattered everywhere and has pushed a bunch of things around. There's normally not that much crap lying around on the workbench, and I just noticed that the cords for the angle-sander and hammer drill are lying untidily on the floor. (shame.)

I noticed something interesting about the controller I've got from Cell_Man; on the underside, written in marker, it says "1,00 mΩ." I assume that this is the shunt resistance, but I just find it odd that it came out to exactly 1.00 instead of .97 or 1.02 or something. In my experience, it's extremely unusual for components to actually meet their specified value. Are these devices typically inspected and calibrated individually, or is 1 mΩ just the nominal value?

[o00scorpion00o]

Nice one! Nearly there.

Was it the 12T again ? can't wait to see what you think of it with a good battery!

[Joe Perez]

Nice one! Nearly there.

Well, we're getting there.

One thing I've discovered is that trigger shifters are a pain to deal with. The half-grip twist throttle which I got from Cell_Man sort of fits, though I had to rotate it 180° from normal such that the pushbutton and rocker switch are on the top and facing forward, and even at that I find it ackward. My old thumb throttle didn't fit at all. Not real happy about the way that's all going together at the moment.

Thinking very seriously about swapping the shifter out for a twist-shifter like I had on my old bike. It's a Shimano X4 (1:1) so I've gotta find something that will fit with that quirky arrangement.

I've installed only one of the DocBass torque arms, on the non-chain side. A little grinding to both the torque arm and the frame were required, but it seems to fit like a champ now. The though that it's being held in place with nothing but glue is kind of spooky, but we'll see. On the chain side, I couldn't' figure out how to make the darn thing fit with the derailleur, so for now I've got one of my old e-bikekit shorty arms there. Somehow I don't think I'll be making enough power with this system to destroy anything with that combination.

Was it the 12T again ? can't wait to see what you think of it with a good battery!

10T. After the video which was posted a few pages back, that seemed like the winning combination. We shall see.

[Joe Perez]

First ride today!





Just a quick trip around the apartment complex, as I'm still waiting on the big battery, so for now it's just a 36v pile of old SLA tie-wrapped to the rack. The two white ones are 10Ah borrowed from a UPS, the small black one is a 5Ah unit I swiped out of the security system in the apartment. Even with this mediocre power source, the performance is quite impressive. Compared to the old Amped direct-drive motor at 48v, this one accelerates much faster and more smoothly- it's a torque monster. No idea as to top speed or hill-climbing, that will have to wait for the 52v battery.

The freewheeling geared motor is also great. Apart from being a tad on the heavy side, it pedals just like a regular bicycle. Some tweaking is still required on the rear derailleur- I replaced the SRAM X4 trigger shifter with an X5 twist shifter, because A: I prefer twist shifters, B: it allows me to use my old thumb throttle as opposed to the new twist-throttle that the kit came with, and C: it allows me to "nudge" the derailleur if the chain is having trouble dropping onto the next gear. It's still an 8-speed shifter on a 7-speed gearstack, so I may never get it perfect, but its usable. Worst-case, I have a seven-speed shifter / derailleur combo on the old bike that I can transplant onto this one if need be.


Same basic configuration as the last bike insofar as the controller and wiring mounted to the underside of the rack. I had to buy a different rear rack to clear the disc brake caliper, but it's the same model as the last one (Topeak Explorer), and has the same basic dimensions. I'm also ditching the plastic milk-crate, and going with two smaller foldable wire baskets on the side for this bike. They weigh slightly more than the milk crate, but the weight is much lower- better for handling, and a lot more stable when putting the bike up on the centerstand with a full load of groceries. Only one basket is mounted at the moment to leave me with wiring access.





Unsurprisingly, the Cell_Man kit comes with the same crappy white flat-pin connectors that seem to be the standard in the industry.

Good-bye.



Fortunately, we have the proper tooling for Molex Micro-Fit 3 connectors at work, so I've replaced all the low-current interconnects with those, and used Andersons for the high-current stuff. The Cell_Man controller and motor already had Andersons on the phase wiring, but used the crappy connectors on the battery interconnect. I used the same connections on the front end, on the CA, the throttle, brakes, etc.

It's kind of difficult to get a good photo of a black connector on a black wire against black handlebars.




Seems like there are still one or two bugs in the CA3 beta (the temp reading is kind of squirrely right now) but it's definitely working. As a sidebar: with the rear wheel in the air, you can indeed use the rear brake as a dyno load for testing and calibration.

This, however generates heat.

A lot of heat.

As in "Hmm, what's that smell? Oh, my rear brake is on fire. I should probably stop now."




And the DocBass torque arm. I only did the wire-side for now, since I can't quite figure out a good way to put one on the chain-side just yet.




Paul has promised that the triangle battery should be shipping "soon."

The wait is killing me.

[Ykick]

Molex upgrade looks nice! Those cheesy white connectors are a Chinese joke on US IMO. You're gonna get wide-eyed with A123 battery compared to that pitiful SLA though.

Looking good Joe!

[Joe Perez]

First off, a big thanks to everyone who contributed along the way. It's been a long road getting here, but the bike is finally done. First commute today, and I am seriously impressed.

The hills no longer exist. They are simply gone.

When I built the first bike, I thought I was making a wise choice selecting a direct-drive motor based purely upon the motor's size and rated capacity. I now realize what a horrendous mistake that was. This diminutive little planetary motor is an absolute torque monster. Those 15% grades that used to darn near kill me before (and which did, in fact, result in the destruction of the Amped bottle battery- twice) simply aren't relevant anymore. Even though I have the current limit set to only 25A on the CA, I was still gunning it up those hills at 15-20 MPH without the slightest sign of protest from the bike. Motor temp never rose above around 50°C, so I'm apparently not even pushing it all that hard.

Admittedly, it's not much to look at. No penis-shaped holes in the motor or anything:





But this one's a definite winner.


I took the short route to and from work today, covering 9.7 miles and consuming 3.9 Ah with moderate pedaling, so I'm quite happy about the efficiency. Despite the fact that I was burning needlessly large amounts of power gunning it up the hills to see what it could do, range should not be an issue. I'm also finding the throttle re-scaling function of the new CA3 to be quite handy. After I got into work, I re-scaled the throttle (such that full throttle in = 2/3 throttle out) simply to make it easier to start the bike from a stop without wheelie-ing it. I'll be happy when the non-linear rescaling gets implemented (eg, so that the first 10% of throttle input only gives you ~1% of throttle output, and then linear to 100% = 100% thereafter) but for now this is more than adequate.

[Ykick]

Looks like a very practical ride! Clean, tidy, good balance, decent brakes, probably 25 mile range easy. You did good...

[Joe Perez]

Power utilization is getting better as I get back into shape. Yesterday was about 19 Wh/mi, which is just phenomenal considering the hills around here.


Something really strange happened this morning, though, and I'm still a little freaked out by it.

I was cruising down Poinsettia Ln. going east on my way into work. Poinsettia is four lanes, divided, with wide bike paths. Very nice road, good visibility. Speed limit is 50 MPH, and I was doing about 30-35 (going downhill with the motor freewheeling, pedaling like a madman.)

So coming up behind me and on my left is an SUV. He passes me and is signalling a right turn. I was going sufficiently fast that he only had maybe a 30 meter lead on me by the time he got to the intersection, at which point he *stopped* and waited for me to pass before making the right turn.

?!?!

The natural behavior for any driver in the US, and even moreso the driver of an SUV, is supposed to be either complete oblivion towards bicyclists, or to act in a way which maximizes the probability that the bicyclist will be killed. So needless to say I was already hard on the brakes and slowing in preparation for the impending assault. But not only was this fellow aware of my presence, he actually YIELDED to me, rather than attempting to murder me.

What is this society coming to?

[richmpdx]

Yes, I occasionally encounter considerate auto drivers who risk getting rear ended by another car because they stop in a situation like that. Of course, on a bike you become essentially invisible to most motorists, so assuming they will cut you off is a survival necessity. I have enjoyed reading this thread. Glad you have achieved the desired results with your build. Seems like a good selection of components and capability to make a reliable commuter ebike.
Rich

[Ykick]

I'm conflicted about drivers who stop in lanes to give right of ways in situations like you describe and other encounters. While it may provide a warm fuzzy feeling about SUV drivers and we should appreciate the gesture it can also create complicated hazardous situations.

One example is gridlock traffic on 4 lane roadways - from the inside lane Mr SUV decides to stop and allow oncoming vehicle to turn in front of them. Unfortunately, what about the box truck sitting behind Mr SUV blocking a clear view of the outside lane?

How about in your situation if Mr SUV wasn't stopping for you but instead double checking an address before executing the turn and then decides to go and takes you out?

Unfortunately most drivers don't have enough common sense and training to account for hazards of granting right of ways. Especially, in unusual compound situations. I do appreciate attentive drivers of hurtling machinery and while their hearts' in the right place, I always assume the worst and plan accordingly.

MSF is the best place to learn how to read and decipher traffic situations.

[o00scorpion00o]

Hey Joe,

Well done, nice build, nice and clean. I knew you would be impressed with the Mac.

Those triangle bags really work a treat, shame you can't get anything like that here.

[Joe Perez]

I declare my Independence... from gasoline!

(Just occurred to me that I haven't driven my car in two weeks.)

[GMUseless]

Hey Joe. Congrats on your emancipation! I just caught up with your build thread today. Glad to see you got a MAC...those bitches are so surprising for how small and compact they are. And crazily efficient as well!

How's your wH/mile holding up?

After two weeks in the saddle...cretainly the build bug has you eyeing some upgrades?

[Joe Perez]

Hey Joe. Congrats on your emancipation! I just caught up with your build thread today. Glad to see you got a MAC...those bitches are so surprising for how small and compact they are. And crazily efficient as well!

Yeah, it really was a shocker, especially moving up from the old Amped system that had been giving me so much trouble. There haven't really been any updates here because there's just not been much to report. This thing is working perfectly, and does exactly what I hoped it would.

There have been a couple of occasions where it felt like I was really straining the system, but then I've realized "hmm. I'm going up a 10° incline at nearly 25 MPH. I could probably slow down just a tad."

How's your wH/mile holding up?

After a full day's commute cycle (10-14 miles, depending on route) I'm averaging in the 17-18 wh/mi range overall. It's higher in the morning, as I'm going mostly uphill, lower in the afternoon. And of course the pedaling effort is much higher coming home from work than heading in, as I'm not as concerned with arriving home dripping with sweat. On the weekends, when I just go out for shopping for for fun, I see as little as 14-15 wh/mi (generally this is less hilly terrain as well.)

After two weeks in the saddle...cretainly the build bug has you eyeing some upgrades?

Not really.

This bike *IS* the upgrade from the last one. Totally new build from the ground up. If I lived on flat terrain, it would actually be massive overkill. As it is, this seems to be the real sweet-spot. I feel like I'm right at the upper limit of having a "motor-assisted bicycle" as opposed to a scooter. Any more power and there'd be no point in having pedals and a chain.



Also, for those who didn't get the joke in my last post, 04 July (date of post) is the anniversary of the signing of the US Deceleration of Independence from the British Empire.

[tyrion]

As a fellow San Diegan considering a Mac motor from cell_man, I really enjoyed reading this thread. Thanks Joe for documenting your thinking, decision, and build.

I'm thinking of going with the 10T and frame battery as well. Also on a Giant (although older model) hardtail mountain bike. I don't have many hills on my commute but there are certainly a bunch around San Diego and I'd like to be able to ride around without having to fear them.

A few questions (if you're still following things):

Could you update on how everything is running after a full summer of use?

What kinds of top speeds are you seeing (without pedaling)?

What size is your frame?

Anything you wish you had done differently? Different battery? Motor? Full suspension? etc...

Thanks again!

[veloman]

Yes the Mac's have great starting torque and seem to do "more" with peak watts than a DD. Great option if you are running lower battery power and have hills or lots of stops. But, my 9c is more efficient at cruising and if I am smart with the throttle I can get better wh/mile, especially with regen in the city.

The other problem I had with Macs is the inability to handle heat and going over 90 degrees Celsius at 20wh/mile in 95 F ambient temps. Even at 15wh/mile the temp would still keep rising above 90 C, and it was only 85 F!

[Joe Perez]

As a fellow San Diegan considering a Mac motor from cell_man, I really enjoyed reading this thread. Thanks Joe for documenting your thinking, decision, and build.

I'm thinking of going with the 10T and frame battery as well. Also on a Giant (although older model) hardtail mountain bike. I don't have many hills on my commute but there are certainly a bunch around San Diego and I'd like to be able to ride around without having to fear them.

A few questions (if you're still following things):

Could you update on how everything is running after a full summer of use?

It's been just absolutely fabulous. The old AmpedBikes system always felt anemic and underpowered, popped fuses at least once a week, and blew the BMS twice. The Cell_Man system, by comparison, has been 100% reliable. The CA3 firmware had a few bumps along the way during the beta phase, but it has now reached a good level of stability, and the closed-loop current mode throttle works wonderfully (eg: push the throttle to 50% of travel, and you get 50% of rated current regardless of speed or incline.)

All in all, the system is working exactly as I'd hoped.

What kinds of top speeds are you seeing (without pedaling)?

I have no idea, as I always pedal. With average effort, I can easily cruise at 25 MPH on level ground, climb moderate inclines at 20 MPH with heavy pedaling effort, and my top speed downhill so far has been 36 MPH.

What size is your frame?

It's a "Large" in Giant's terminology, whatever that translates to in the real world. I'm no bicycle expect. I am about 6'2", and this frame is probably a tad smaller than would be recommended for me, but I've always preferred smaller vehicles, be they cars, motorcycles or bikes.

Anything you wish you had done differently? Different battery? Motor? Full suspension? etc...

Not really.

The motor is just fabulous for my needs. The battery has also been great. If there were a choice to have it wired for 20S4P instead of 16S5P, I might be tempted to go for the extra voltage, but this is honestly a trivial point. Stepping up from an anemic 36v battery to this rugged 52v powerhouse was the difference between night and day.

As to full-suspension... When I first started frame shopping for this bike, I was leaning in that direction mostly because I thought it looked cool. But there are two major factors weighing against it. Battery fitment is one, and the other is that a rear suspension tends to soak up some of your pedaling effort, resulting in reduced efficiency. And having a hard-tail hasn't really been bothersome. In part, this is probably because I tend to stick to pavement and very well-maintained trails (mostly pedestrian walking paths between housing developments and office parks.) I'm not running especially fat tires, either. Given the choice between a rear suspension and having the perfect place to hide a large battery, I'll gladly give up the suspension. It's just not needed for a commuter bike.

[Joe Perez]

Yes the Mac's have great starting torque and seem to do "more" with peak watts than a DD. Great option if you are running lower battery power and have hills or lots of stops. But, my 9c is more efficient at cruising and if I am smart with the throttle I can get better wh/mile, especially with regen in the city.

No doubt that a direct-drive will be capable of higher efficiency given the right terrain. In my case, I'd already tried a 9c, and with the hills we've got out here, it just wasn't the right thing.

I also didn't really anticipate how much better the geared motor would be in terms of freewheeling when unpowered. With my last motor, I just wrote it off to having a heavy bike. But now that I have a geared motor, the bike really is much more pleasant to ride when I'm on flat terrain in pedal-only mode. It no longer feels like I'm dragging a bag of dead cats behind me with a flat tire all the time.

The other problem I had with Macs is the inability to handle heat and going over 90 degrees Celsius at 20wh/mile in 95 F ambient temps. Even at 15wh/mile the temp would still keep rising above 90 C, and it was only 85 F!

You must be pushing it a lot harder than I am.

In my daily commute, I hardly ever see 60 degrees C by the end of the ride. The highest temp I've seen was 72 degrees, and that was after a 21 mile ride on varied terrain. Obviously I was keeping an eye on motor temp and trying not to let it get too high, but I can't imagine what I'd have to do to push it to 90.

[veloman]

nope, I am at the same wh/mile as you, so not pushing it harder. Mine is an 8 turn, but its not hilly here.

What is your ambient temp?

[Joe Perez]

What is your ambient temp?

Morning are usually in the low 70s, afternoons can be anywhere from the mid 70s to high 80s.

My typical end-of-ride temp (5-6 miles of moderate terrain) is typically in the 50-55 degree C vicinity, depending on how hard I've been leaning on the system vs. pedaling.

One thing I have a hard time figuring out is just how hot is "too hot". Hall sensors of the sort we commonly use (eg: SS41, AH3503, etc) are typically rated for operation all the way to 150 degrees, and while I have no solid data, I can't imagine that the varnish on the windings would tend to fail below that point either.

[Trilska]

This might end up being a late kidnaping, but i got inspiered about mac talk, and sence i am in a simular situation i hope i could get some advice.

How does a 12t MAC in a etro 405 wheel (20'') sound?
And sence i am after around 50km/h i figure i would have to feed it around 90-100V(24s lipo).
With a total weight of around 150kg would this system have posibilitys to be relable, or will i just end up destroying somthing?

And when we talk about something getting destroyed, will it be the gears or the clutch? And how much of a factor is heat in this equvation? Sence the heat isue is the nr 1 reason that i am qonsidering the 12t and then throw voltage at it to get my desiered speed.