A Dirty ELF

Back in December of 2015, I went to work at a startup company in Durham called Organic Transit. The company was then located in a small warehouse in downtown Durham and had been operating for a couple years. I had just gotten laid off as an engineer working for Lenovo and decided to respond to an OT ad for a Senior Engineer. Turns out the owner, Rob Cotter, only wanted a build technician but it sounded like it would be interesting work. The pay, at $15/hr, was definitely not a consideration. Something to do for a couple months while looking for a new engineering position. I actually enjoyed the work, like working in a machine shop, which is something I’d never done before. The ELF’s were all hand built, no assembly jigs or automation. The frame was welded and bolted together and the fiberglass, molded body was riveted to the frame. Many parts and panels were hand cut and bent to fit. Kind of like working on a custom bicycle in your garage, only bigger.

One of my tasks was to redesign the wiring harness and document it. The company wanted to go into the next phase of mass production and for that they needed CAD drawings and other assembly documentation. Basically the main wiring harness connects the display and handlebar controls to the Kelly motor controller, and rear tail lights, direction lights and brake lights. It runs from the handlebar controls, across the steering bar to the left side panel, down and along the base of the body panel to the rear section of the ELF. There the bundle splits off into separate connections to the Kelly controller and 3 sets of rear lights. The final design has the harness connected to a terminal block under the steering bar. This ELF did not have the terminal block and had been apparently re-wired by someone to use indidual JST connectors and/or spliced wires.

Fast forward 10 years to my first ELF repair. The customer’s complaint and how I ended up servicing this ELF was the display did not turn on when the key was turned. He told me he had been having intermittent problems with turning on the display and this time it stayed broke - probably a wire connection issue. In order to check this out I had to get at all the wiring which turned out to be no easy task, as indicated in the picture. As soon as I undid that massive taped and wire tied bundle, the display started working, more evidence this was just a connection problem. Incidentally, that black aluminum box dangling in the 3rd picture contains the key switch, turn signal flasher and aux power relay. I bugged all of that out to verify connections were good and also added insulation to prevent shorts and water damage.

I found one poorly crimped wire in the JST power connector to the display, which I fixed. I also used contact cleaner to clean all of the JST connector terminals, which were all green with corosion. I replaced the worst connectors. I also noticed some of the spaghetti wiring was much longer than it needed to be. It was as if someone had just been grabbing and randomly connecting different wires until they had something that sort of worked. I removed much of the extra, unneeded wire and solder spliced wires when necessary to prevent loose connections. I added shrink wrap tubing to all splices and all JST male/female connections to improve durability and prevent water damage.

Now I had the display, motor and rear light power all restored for this ELF. I could shake and pull the wiring with no effect, so connections appeared solid. I noticed the front headlights were a bit flakey. I traced a separate, also messy, wiring harness from the headlight switch on the handlebar to the front of the ELF. I found and fixed the loosely taped (yeah, no connector, no solder) connection near one of the headlights. I soldered and taped it properly. I also used a stick on cable tie mount to secure the wires along the body panel. Now all lights, front and rear, motor and solar power appeared to be working correctly. Next for the real test, bundle everything up nice and pretty and give it a bumpy ride to verify the connections hold up and nothing falls off.

While I was under the carriage checking out the wiring to the motor controller, I noticed something interesting. No chain connecting the Nuvinci transmission to the pedals and no chain from the Nuvinci to the left sprocket on the rear wheel. The only thing driving the rear wheel was the DC motor. I asked the customer about this and he was fine with it. Just as well, as it would have doubled my labor to rebuild the pedal assist transmission. I’ve been told the Nuvinci drive train is one of the most common failures on an ELF. Perhaps I will become an expert on that. :-)

The road test went well. I noticed the motor was a bit slow to start, sometimes requiring ground foot assist (similar to The Flintstones), but drove well once it got going. I informed my customer that his ELF was ready for delivery. Actually I had one more important task. I promise my customers to return their bike in better condition that I received it. One of the ways I do this is clean and tune it for free. This poor ELF needed a lot of cleaning, hence the title of this blog. While removing all the dirt and spider webs I found other issues, like gaps around the solar panel mount, which I caulked and a slight rubbing of the front wheel against the body fender. I fixed the latter using a heat gun to remold the fender away from the wheel. I could tell someone had already tried that but had not finished the job.

Lessons learned? ELF’s were hand built and had many interations in the build cycle, so every one can be considered unique. I have wiring schematics from OT that were of little to no use because of the customer wiring job previously done on this ELF. There is a big difference between upgrading and repairing. I need to make that distinction with my customer to manage their expectations. Fortunately, my customer had low expectations and just wanted the vehicle to turn on and the throttle to make it go. The job would had been much bigger if he has wanted me to fix the pedal assist (replace the Nuvinci drive) and/or beef up the power (i.e. replace the motor and control system). Along with that lesson comes the corollary, be prepared for the unexpected, either by building it into the quote (within reason, since I hate overcharging my customers) or by modifying the original estimate with full transparency on the reasons for the increase. The quality of my work and the integrity of my business is of greatest importance to me. Overall, this was a rewarding challenge to clean up this ELF and I look forward to more fixing more ELF’s and making their owners happy in the future.