PS did you edit out the details of the two companies you were debating between for buying e-bike parts? I can't find that anywhere.
Huh, no I didn't edit anything.
The company I ended up buying this package from is actually just one guy named Paul, a Brit who lives in China. His website is kind of crappy: http://emissions-free.com/
Paul is a highly active member of ES, and is notorious for taking days to respond to emails (even those containing large sums of money via PayPal), however that's pretty much the only way to reach him: firstname.lastname@example.org He seems like a decent guy, and unlike the clowns at AmpedBikes, Paul actually seems to understand the tech behind the stuff he's selling.
There are a couple of companies in the US that also sell the same stuff, but the one thing Paul brings to the table which nobody else can match is the battery fab. He assembles custom battery packs using A123 LiFe cells into shapes that actually make sense on a bicycle (such as the triangle pack) rather than just big square bricks that don't actually fit anywhere on a bike.
Send him an email and just say you're looking around, deciding what you want to buy. Describe the length of your commute and the terrain (elevation, mostly), and ask for a motor recommendation. My guess is that he'll point you towards the 8T motor.
I believe you're correct. The laws seem to be on the books only to allow the municipalities to cover their asses in case somebody does something extremely stupid, such as building a 10kw ebike (it's been done) and then riding it at 60 MPH on the sidewalk (again, it's been done) and killing a bunch of pedestrians (hasn't happened yet, to my knowledge.)
Right now, nothing is more politically popular in the US than being perceived to be "green", and being seen to encourage others to do the same. To the best of my knowledge, an e-bike is the single most energy-efficient means of transportation in all of human history, including walking. It actually takes more energy to grow the food crops that you'd eat to replenish the calories that you'd expend walking 5 miles than it does to charge an e-bike and ride the same distance. (Fact.)
Even in Europe, where most nations have both strict limitations on maximum motor power and a requirement for pedelec sensors, I can't really hearing of a single member on ES ever actually being hassled in this regard, although most of them do seem to ensure that their bikes can at least be easily and discreetly switched into "legal" mode should the need arise.
The elected kind, who (if they're smart) understand that the negative PR resulting from headlines claiming "Mayor Douchebag Orders Police to Crack Down on Eco-Friendly Commuters" to outweigh a few hundred dollars in registration fees.
*Bonus points if you understand, without having to google it, why the Palatino Linotype font is appropriate for the above headline.
Still waiting on the proper battery pack, 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.
The CycleAnalyst BCU (my freshly made-up term for the bicycle equivalent of an ECU) isn't connected yet, so the system is just running on the "dumb" controller, but it's a big step towards completion. Now to start into the BCU wiring.
The neat thing about these centerstands is that you can drop the legs a bit more than normal to raise up one wheel of the bike. Since the battery isn't in place yet, the bike is tail-heavy. I needed something I could tie a piece of twine to in order to pull the front end down (thus raising the rear wheel off the ground), and the propane tank just happened to by lying there.
Other items which I contemplated using were an intake manifold, an Optima red-top battery, and an engine block, but the propane tank was just the right weight and had a convenient handle on it.
Controller wiring on the bench, connected to the bike and a few basic I/O. Those white connectors are utter crap (standard issue on all e-bikes) and they're all being replaced with Molex Micro-Fit 3 connections. (It's so nice when you have access to high-end tooling and connectors at the workplace.) A few of the wire bundles will be removed altogether:
Internal modifications to the BCU, adding wiring for a throttle input, temp sensor input, and brake sensor input, in addition to the main I/O trunk and RS-232 cable already installed. It just occurred to me how similar this thing is to a PCPro in both form-factor and function:
The BCU connected to the controller and powered up for the first time (controller is disconnected from bike, this is just a power and comms test):
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 SLA tie-wrapped to the rack. Even still, the performance is quite impressive. Compared to the old direct-drive motor at 48, this one accelerates much faster and more smoothly- it's a torque monster. No idea as to top speed, as that will have to wait for the 52v battery.
The freewheeling effect of the geared motor is also nice when you just want to pedal. Virtually zero drag, as compared to the old motor which was not only a great deal heavier but also placed a lot of drag on the axle when un-powered.
Same basic configuration as the last time insofar as the controller and wiring. I had to buy a different rear rack to clear the disc brake caliper, but it's the same model as the last one, and has the same dimensions. I'm also ditching the plastic milk-crate on the top, and going with two smaller foldable wire baskets on the side. They weigh slightly more than the milk crate, but the weight will be much lower- better for handling, and a lot better for 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.
The CycleAnalyst BCU is kind of neat. It measures system current by tapping into the 1 milliohm shunt in the controller, and can then compute realtime power. The throttle signal passes through the BCU, and can be re-scaled as well as limited based on both power and temperature. The temp sensing seems to be a tad wonky at the moment, though admittedly this unit is still in beta. It also has a number of dashboard screens that let you see all operating parameters in real time, including an estimated state-of-charge gauge for the battery (based on observed discharge vs. known capacity) which is handy since LiFe batteries have a nearly flat discharge curve and thus, their state-of-charge cannot be estimated from their voltage.
Since this is an aluminum frame, beefing up the dropouts was a must. Here is one of the reinforcing plates (the black C-shaped thing between the outer nut and the frame), which is made from 10mm hardened steel, cut to fit the flats on the axle tightly. It's attached to the frame with glue. Yup, glue. 3M Scotchweld DP420, to be precise. This stuff burns when you get it on your skin and is supposed to bond two objects together more strongly than true love, so we'll see. I ground both the frame and the plate down to shiny metal before bonding, then overpainted the finished assembly with Eastwood's clone of POR-15, which dries nice and hard.
It's kind of funny- I've been working on this thing for a week's worth of evenings, and it hardly looks any different from a standard bicycle.
Last edited by Joe Perez; 05-20-2012 at 08:52 PM.