The e-trike project

Updated 5/4/25 (scroll down)

Last year, my brother-in-law let me try to ride his e-bike. We were at camp, and it would have been maybe 2 blocks to the bathroom building. I couldn't do it. I couldn't keep my balance. I was afraid of that happening. If I have trouble walking, riding a bike was not going to be any easier. I was disappointed, but I have slowly been accepting that I am neurologically not the same person as I was 10 years ago. Paula did not want me to miss out on bike riding though, so she started looking for e-trikes. As much as I didn't want to get any kind of trike because it screams "old person," I also didn't want to sit at the camp site when everyone else was biking the carriage roads (Acadia National Park.)

She showed me an ad for a Greenspeed recumbent trike that had been converted into an e-trike. It was being sold by someone who worked with a group that would put together inexpensive bikes for people who could not afford bikes. He rode it around, so I know it was well tested, so we drove to his place and I test rode it. It took some getting used to, but I liked it enough to buy it for $1000.

We brought it home, but it was a week before I could take it for a decent ride on one of the local trails. I definitely liked it. I could ride a bike without worrying about balance, plus it not only has a pedal assist motor but a throttle on the right hand grip that will power the bike without even pedaling.

When we bought it, the seller told us that the motor could handle a more powerful battery if I was to swap it out. I left it alone for a month, but there was one thing I knew eventually I would have to address. There was a rack on the rear tire but the battery was not mounted to it. Instead, the battery was just stuck into one of the side bags. (The previous owner's kid would ride on the rack.) Not only does it look weird but it takes up half of a bag. I posted some pictures of the battery to a Reddit e-bike sub asking if anyone recognized it, but no one responded that they did. I decided the only way to get it done properly was to replace the entire battery and mounting rack. I ran one past the previous owner (he sent me a bunch of video links about the trike and said he would help me out) who said the battery and rack would work, but I would have to reprogram the bike computer because the new battery was more powerful. If not, it would give me incorrect battery stats.

Mounting the new rack was not difficult, except for where it is supposed to connect behind the seat. It looks like the rack can be mounted using different connections to accommodate different bikes, but there isn't anything that works. Most of the e-bike batteries and racks can be adapted for e-trikes, and there were some comments from people who had done exactly that, but it quickly became obvious that we would have to make some sort of metal connector. Fortunately, Paula was already formulating a plan (she's mechanically inclined like that.) She picked up some metal pieces from Home Depot, bent them to fit, and drilled out some screw holes.

This is what it looked like without any straps to hold it. Notice the duck supervising.

They fit! As I type this, the strips are hanging, drying from a coat of black spray paint.

Update! The strips are attached and the battery holder is now screwed into place. It all fits together! (Again... duck.)

I wired the battery to the controller, but the computer will only turn on for a second. I also have no power to the motor when I hit the throttle. I messaged the guy who sold it to me - he is all too happy to help, even offered to look at it if I brought it to him. He misses it and said if I can't make it work he'll buy it back. Feels good to know that, but I am going to make this work. I connected the old battery, but it still won't work. Now I am hoping I didn't blow the controller, but he said as far as he can tell without being here, everything should still be working. I have to look up the manual for the controller to better troubleshoot it. That's a job for tomorrow.

Another update: After exchanging a few messages with the previous owner, I traced the computer wire back to the controller, unplugged it, and then plugged it back in. It goes on and stays on! Tested the throttle, wow, that works too. Unreal. All this for a loose cable. With any luck it'll be nice enough next weekend to take it for a quick ride, then I can get it off Paula's work table. She'd like to have it back. 😄

Update 5/4/25

I did some more work on it over the past month. Every time I thought I was putting on the last part, I needed another part. First it was a set of lights. Supposedly, the controller has output for a light set, so I can hit a button on the computer and the lights come on. Turns out that the controller does not output enough power to run a light, it just acts as a relay switch. I read posts from a few people who put something together that works, but it involves parts, a soldering iron, and knowledge that I either don't have or might have had once and forgot. Then someone on Reddit suggested I go with rechargable lights and be done with it, so that's what I did. I wanted to mount them on the steering bar so they turned with the wheels, so I got one for each side. Got them, charged them up, and damn are they bright. They can charge off the battery on the trike, plus they also have a USB charge out mode, so I can use one to charge my phone if I have to (or, original plan is to have a USB cable split for lights and phone.) I also have a phone holder for trail maps and such.

I started putting all that on the trike, along with a new bike computer. The one I had on there apparently did not work well with a higher voltage battery, so I checked with an e-bike site. Owner confirmed it would work with my motor controller, so now it has a new computer. Mounted that with the lights and phone holder, but then I found that the loose cable that caused trouble before was not the wire going to the computer. If you connect everything and wiggle the battery wires on the controller, the computer goes off. I think when I was wiggling the computer cable and observing it losing power, it was because I was also moving the battery cables. (For most of this, the controller was not mounted to anything, it was hanging by its cables.) I have no idea how old this controller is, so for $70 I replaced that too.

I started wiring everything up on Saturday, but it involved holding wires and stuffing them through a small hole in the pouch holding the controller, and zip ties and velcro and my left hand just won't do that anymore. So, Paula had to help me wire things up. Took a few hours, but eventually we got it all working. I was so overjoyed when we connected everything up and the computer not only turned on, but stayed on. She picked the back of the bike, I hit the throttle, and.... nothing. Um.... okay. Start poking around the wires that connect to the controller, and aha! The throttle wire wasn't plugged in. Whoops. Okay, take two... lift up the back of the trike so the wheel's not touching the table, hit the throttle, we have ignition. WOOO.

We had to adjust a few things for placement because they didn't fit, then I found out that the 4' USB cable to go from the battery to the hand grips was not long enough. So glad I ordered that special off Amazon because Best Buy and Walmart didn't have it. Oh well, at least that's easy to wire later, if I even bother. It's on the list of "nice to have but not critical." But, finally it was time to take it off the table for a test ride... or so I thought. Naturally, it was raining out. So I figured we would at least get it out of the basement and into the garage, but once we got it outside the rain broke a bit. Okay, let's take a chance!

First thing I noticed was there was no pedal assist. I couldn't get up the inclined driveway without using the throttle. Either I didn't have something set correctly or we had another cable not connected. I made sure pedal assist was turned on at the computer, but it did not work. Okay, that goes on the list of things to check. Now that it was outside, someone would have to get down on the ground to check the controller. By someone, I mean Paula, who volunteered to do it the next time we had a nice day. Once I got it onto the road, I was able to pedal it just fine on my own power. This being a new and more powerful battery, it means longer life and faster speed. Of course, I had to test that. So I pedaled to one end of the road, spun it around, and opened up the throttle. You usually don't associate 20mph as "WHEEEEE" but when you're on a bike close to the ground, 20mph is fast. Plus it was faster than it ran on the old battery. While turning the bike, I noticed two things: the bike computer hits my leg when turning left, and the phone holder gets in the way of the right brake lever. Future remodeling. The main goal had been met though - this was the first trip using the new battery and controller, and both worked. Well, okay, the computer was mounted upside down (possibly when we were adjusting the mount.) Must fix that too.

So for now, it's tucked into the garage, next to its big brother. I was hoping I could take it to school for Ride to School day on Wednesday, but it's going to rain all week. Because of course it it... if it's not taking the Slingshot out too early and getting snow, now it's the trike. Oh well. At least when the sun comes out, I'm ready.