I Built An E-Bike Entirely Out Of Trash

Trash Ebike Ts2
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Those of us who are perpetual tinkerers know that sometimes we find projects and sometimes projects find us. The Trash-E-Bike, aka the IEB (Improvised Electric Bike) was a project of the latter sort. I never asked myself, “Can I build an e-bike out of trash?,” and though I eventually answered that question in the affirmative, the project was not especially planned. Instead, the IEB grew, bit by gathered bit, not unlike fast food wrappers and discarded plastic bags collected against a chain link fence by an afternoon breeze.

As a bicycle enjoyer, I find myself riding along LA’s urban rivers all the time (we have two besides the famously concreted LA River). In a city built around the automobile, the river paths offer a place where you can ride for miles and miles without ever encountering a car or a stop light, and, depending on which sections of the rivers you ride, you even get to experience a bit of actual nature in the form of herons, ducks, songbirds, rabbits, coyotes, turtles, and frogs.

Alongside that natural splendor are the many things cast off as useless by our society, three-wheeled shopping carts, half submerged vans, people with untreated mental illness, and bicycles in various states of disassembly (most of which have been left there by the homeless folks).

Last summer, when a friend of mine purchased a bare bicycle frame from Craigslist and told me he needed a fork and handlebars for it, I suggested we go down to the river and see what we could find.

Stubbed Toes And Incredible Bargains

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Of the two rivers I live near, the Rio Hondo (Spanish for wide river) seems to be the better one for finding interesting discarded stuff. My friend and I rode our bikes down there, keeping our eyes trained on the brush and trees that line the river’s banks. We soon came upon a site with piles of bicycle and bicycle parts.

As we picked through the rusty, and sometimes burnt bicycle frames and parts, a man emerged screaming and limping from the nearby bushes. I didn’t know what else to do in the moment besides ask him if he was all right. He said he was and that he had just stubbed his toe while trying to jump across the river (in actuality, the Rio is not very Hondo). Then he called to another man living in a nearby tent, who emerged, shirtless and sporting a dark and gnarled scar that reached from his belly button to his breast bone.

I asked the scarred man if the bicycles and parts were his. He said no, but that they belonged to his friend, who lived a little further down the river but was away buying groceries. He asked if we were looking for something specific, and I pointed out a partially stripped Bridgestone frame we had been looking at and a large wire basket. He said we could have both for $5. What a deal!

Back at my place, my friend and I disassembled the bike frame and its fork from each other, and my friend left with the fork and handlebars. I was left with a frame I didn’t need and that was too small for me. I almost put it out on the curb for one of the junk men to pick up, but then I started to wonder if I could make the bike frame bigger. Inspired by a book given to me by a friend, I decided to give it a try.

The Incredible Expanding Bike Frame

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If you look at bicycle frames, you’ll notice that most of them are built around a triangular core. That triangle can be made larger by increasing the length of each side, and if they are lengthened by the right amounts, the triangle’s three angles will remain unchanged. So, if I were to chop each side of the frame’s triangle in two and weld in some more tubing, I could make the frame whatever size I wanted it to be. I would never have the heart to do that to a nice frame, but for a dinged-up river frame that cost less than $5, why not give it a try?

My angle grinder made very quick work of the chopping, and some scraps of electrical conduit I had in my garage slip fit inside of the tubing that made up two sides of the triangle pretty well. The third side was made of wider tubing that didn’t match up with any of my conduit, so I went to the local scrap metal place. There, I found a piece of tubing that was the perfect diameter and it cost me a dollar and change. Total cost for the bike so far? About $6.25.

With some math, I figured out how long to make each side, and welded everything together. Just like that, I had a frame sized for me.

The River’s Bounty

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Up to this point, I still hadn’t decided to build a bike. Expanding the frame had just been an experiment to see if I could do it, but then my friend gave me back the handlebars and fork. Now I felt like I should actually try to finish the bike, at least just to see if it was rideable. I went back to the scrap metal place for more tubing so I could extend the fork to match the now-bigger frame. Total cost: $8.25.

With project cars, it’s all the little pieces that end up costing the most (this is why I 3D printed parts for my truck). The same is true for bikes. I didn’t want to spend a lot of money on brakes, wheels, derailleurs, and all the other bits I would need to make the Bridgestone frame rideable. So, I went back down to the river. One day I found a rear wheel, but its bearings were seized.

Another day I found another rear wheel of the wrong size with good bearings. I swapped the good bearings into the other wheel, and now I had a rear wheel for my bike. On other days, I found a seat and seat post, a partially burned beach cruiser with a good set of handlebars and handlebar stem, pieces of chain, brake components, and handlebar grips. Each in turn was added to the growing bicycle, which I had still spent less than ten dollars on. I wonder if Dr. Frankenstein felt this good building a human out of free parts.

A Big Find

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The main piece I still needed to finish the bike was a front wheel, and for months, this eluded me. The bicycle graveyards had dried up. I considered just buying a wheel, but decided to be patient and see if one would turn up. I set the bike aside and put it out of my mind.

I was on a ride a few months later when I spotted a wheel lying in the dirt next to the bike path, not far from where the Bridgestone frame originally came from. It was not any ordinary wheel though. At its center was an electric hub motor.

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I had considered building an e-bike more than once over the last few years, but the expense of the motor and battery had always put me off.

Since the motors are a big part of the cost of building an e-bike, I grabbed the wheel and rode home, doing my best to not crash while clumsily holding it with one hand and steering my bike with the other.

A Brief Explanation Of Brushless DC Motors

The wheel had been lying outside during a particularly rainy couple of weeks, so the first thing I did was open it up to see how it looked inside. Some water had gotten in, but not a lot, and there was only a tiny bit of rust. I left it to dry and began researching what I had.

At the center of the wheel was a 36-volt, 250-watt brushless DC (BLDC) motor coupled to a planetary gearbox. (I also happened to have a 36-volt battery that a friend scavenged from a rental e-scooter someone had left broken down near his house, so I was off to a good start.)

Some motors, like brushed DC motors, will just run when you connect them to a power source. These motors make use of a commutator, an electromechanical device that switches the path electricity takes through the motor’s windings as it runs. That switching action keeps the motor spinning by constantly moving the magnetic field generated in those windings. Commutators are old technology, dating back to the early 1800s, and they’re robust, but they also have drawbacks. The commutator is a source of friction that reduces the motor’s efficiency. It also creates noise, sparks, and ozone gas, and the carbon brushes that conduct electricity into the commutator wear out with use.

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BLDC motors, which are now found not just in e-bikes and e-scooters, but also power tools and electric cars, eliminate those disadvantages by replacing the commutator with electronics that do all the work of switching the path electricity takes through the motor’s windings. BLDC motors are quieter, more efficient, and require less maintenance than their brushed counterparts. The electronics also operate more flexibly than a commutator, which makes it easier to change the speed the motor runs at, and even make the motor run in reverse.

E-bike controllers that include those electronics can be had as cheap as $11 on AliExpress, and e-bike and e-scooter parts are pleasantly standardized, so finding a controller that connected with both my battery and motor was easy. I opted to spend a bit more and got controller that came with a display and a wiring harness for $50, including tax. Total cost: $58.25.

A few weeks later, my package arrived, and, as promised, the controller neatly plugged into my motor and my battery. I twisted the thumb throttle and breathed a sigh of relief as the motor quietly whirred to life.

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I had tires and tubes I had found by the river, but they were sketchy from laying out in the elements, so I went to my local bicycle shop and bought a new set of tubes and tires. At $80, this was the most expensive part of the build. Total cost: $138.25.

Trying And Naming The Bike

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I was excited to try out my new e-bike, but I didn’t have a good way of attaching the battery to the frame. For a test ride, I strapped the battery, housed in a 4-inch drain pipe, to the bike with bungee cords. When I posted a picture of the bike on my socials, friends joked that it looked like a suicide bomber’s bike, and said not to leave it unattended or someone would call the bomb squad. My brother dubbed it the Improvised Explosive Bike, or IEB, and I started calling it the Improvised Electric Bike.

Tidying up the wiring with some 3D-printed pieces and some hose clamps made the bike look a lot less like a threat to public safety, and cost me another $4. I couldn’t find a decent set of shift levers along the rivers, so I bought a set for $12 on eBay. Total cost: $154.25.

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At this point, the bike was basically complete, and everything felt secure enough that I felt comfortable taking out on a real ride, and the results were impressive, at least to me. On flat ground, the IEB is capable of going up to 22 miles per hour—faster than really feels comfortable to me— and that’s without me even pedaling. I think that’s pretty good for something made mostly out of scavenged parts.

Future directions

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I will admit that I spent more money than I intended to on this project, but it still cost only about a quarter of what a used e-bike would cost, and only a small fraction of the price of a new e-bike, and it feels good to know that I sourced the majority of the bike from parts left to rust in the dirt and bushes.

I plan to continue making upgrades to the bike as I find other parts. The most recent addition is a set of wire basket panniers I welded together out of a smashed dog kennel that was lying on the side of the road. Total cost for that side-project: $3 for a bag of hose clamps.

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92 thoughts on “I Built An E-Bike Entirely Out Of Trash

  1. I have to be the pedant who notes that if you paid for new and used parts your E-bike is not ‘entirely’ made of trash. Otherwise Nice Job!
    I’ll get my coat…

    1. It probably won’t go as far as that one. My battery is 36V 12.6Ah, so that’s less capacity right there. My bike is also 250W, compared to that one, which is 500W, so it is probably not as fast either.

      That said, mine tops out at about 22 mph on flat ground and that feels faster than I really like going in the city anyway.

    1. The hub was a very lucky find, but those scooters were so ubiquitous for a few years that it was hard *not* to find them broken and abandoned

    2. In the right circles… extremely easy.

      If I could interest you in one of my approximately 1500 pounds of electric motors lying around…

  2. This is great content, and welcome Emily to the crazy world of Autopian! I just picked up a used bike and replaced a bunch of parts and it works like new now, used bikes are a great!

  3. Great content. This reminds me of the time I borrowed a friend’s bike to ride from Cerritos to the ocean along the San Gabriel River path, opting to bring a THC lemonade with me instead of water. I got so fucking high, found a Walmart for water and snacks, made it to Ballast Point for a beer, got lost on the way back, and ended up looking like a lobster for the rest of the trip due to my high ass not putting on any sunscreen. Fun times.

  4. Now that I’ve slipped some bicycle content into this site, maybe I can convince Jason and David to let me write about the history of China’s Flying Pigeon bicycle.

    1. Please!
      Flying Pigeon bicycles are awesome.
      In 1988 I went to China as part of an official group – long story, somehow through mistranslation and many copying by hand of documents the local government representatives thought I was the publisher of rolling stone magazine, so there were always official tours if things – and I really wanted to visit the Flying Pigeon bicycle factory and the last steam locomotive factory in Datong which was making the world’s last steam locomotives in 1988. Unfortunately it seems that they couldn’t figure out why I would be interested in both bicycles and steam locomotives and it fell through.
      Anyway, the Flying Pigeon bicycles that are sort of a cross between Dutch bikes and Raligh police bikes always impress me. I would see them in Brooklyn but every time I inquired how they came to be in Brooklyn there was some crazy story about living overseas as a child and having it shipped home.

      1. I looked around online and found that I could order 144 for them for a really good per-unit price from Alibaba, but I just knew that if I went down that route, I would end up selling like three of of them to friends, keeping one for myself, and not knowing what to do with the remaining 140.

    2. Not much history in terms of design advancement, but kind of like a time capsule of an old English roadster, though I still see the real things around, if later cable brake bikes rather than rod brakes.

      I really like that old laid back geometry. My 1913 Iver Johnson is a race bike with geometry more like a modern beach cruiser and the ride is extraordinarily comfortable (except for the old drop bars that don’t really have tops as my neck doesn’t tolerate that position well since a couple car crashes). I’m sure the wood wheels are also contributors, but I think it’s primarily the geometry. Damn thing doesn’t handle, but it cruises at a surprising speed (single speed) and it doesn’t bother my knees to ride it as much as it should for being a bit too small (despite barely clearing the top tube), as other bikes that are too small tend to do.

  5. Love it. George Lucas convinced me on the aesthetic of junky tech in my childhood and I’ve been eagerly anticipating this level of tech to fall to tinkerers. So glad you’re out there! Well done!

  6. I built an E-Cargo Trike for my senior design project in college out of a church sale road bike, a used shopping cart, a 1000W eBay hub motor, a few NiCad batteries, and some front wheels from Northern Tool. I think in total I spent $350

  7. Emily, this is a great read. Nice work! I have followed you on Twitter for years via 3D printing related channels and only just now realized you write for The Autopian as well. I am glad to see your content here too, cheers!

  8. Can’t argue with those costs! When I was a kid, I used to make BMX bikes out of junk parts I’d find walking to school on trash day that I’d hide in bushes and such for afterschool retrieval. It was a lot of fun and one I made lasted three years of ghost riding, jumping, etc. I’ve made a few custom bikes as an adult, but I’ve run out of space for them and the builds were definitely not free. I need to finish the e-bike I started.

    1. “one I made lasted three years of ghost riding”
      Late 60s early 70s as a young crazed Adrenalin junkie, found an oak tree that had sloping root structure into trunk into a big limb that looked like you could do a loop. I rode at it at full speed, and bailed last second, and the bike did the loop. We called that “ghost riding” and our goal was to stick the 3 point landing, with the bike inverted on the seat and handlebars and not fall over. Only got that once.

      1. We didn’t have any cool trees, but we did make a ramp so dangerous looking that even our dumbasses wouldn’t actually go over it. “Ghost Rider cleared for takeoff . . . ” Yeah, we would have been in the hospital, but the bike shrugged it off with nothing but some scratches to the harlequin paint made up of four different donor bikes. I don’t recall what ultimately happened to it. Probably eventually stolen by the dirtbag kid in the neighborhood who ended up killing two people later on. We had a concrete slide at a park a mile or so away that was meant to be used while sitting on cardboard. It was made up of 4 lanes separated by embedded steel rails. The entry was vertical and the end of the ramp at the bottom of the slide had a 3′ drop we used to bomb down that and off the end. I think the slide would take too much to destroy, so it’s still there. A few years back, I sat at the top on my bike and looked down, thinking of playing kid again, but I noped the f out since it takes too long to heal now and I need to work.

        1. I gave up motorcycles in my late 20s after totaling two, and many close calls. Not only for the increased traffic, and inattentive drivers, but felt I had aged out of being bouncy, bendy, and into breaky.

  9. this is wonderful, thank you..
    I’ve thought about converting one of the old MTBs lying around the house to electric, now I’m ashamed I haven’t done it yet 😉 compared to your project..

  10. There used to be a punk band named “This Bike is a Pipe Bomb”. A friend and former FBI agent told me a story about how they responded to a university that had found a bike with the band’s sticker on it. Bomb squad came out and everything. He didn’t tell me if the owner got their bike back.

  11. My daughter saved up for two years to get a gas 49 CC bicycle and was not allowed by the seller due to her age. She opted to spend about half on a Happyrun G50 E-Bike instead, which we had to lower with a 4 inch rear shock, but for just under $600 new, that thing is pretty sweet. Perhaps a little too Sweet as it genuinely outruns the 49 CC gasser and is completely ignored by riders of the bike trails and lanes.

    I suspect in the next few years these will get regulated with liceneses, license plates, and insurance requirements, but for now she is having a blast.

  12. So, what’s the electrical connection like up front? Is it similar to a clock spring in a steering wheel, or something much more basic with one fork side being positive and the other negative with the box up top varying power as needed?

  13. Related to this but not really related, I was just discussing the other day how I was amazed that no one seems to make electronic conversions for gas mowers and stuff. I can go to Harbor Freight (or any other number of stores) and get a vertical shaft engine and slap it on basically any mower and be off to the races.

    And yet, I can’t do the same with an electronic motor. Seems like if someone paired a motor, some batteries (ideally, you could choose whatever cordless tool brand you already have) and the controls, you could swap over your existing mower with little work.

    Now, stretch it out to all things… bicycles, riding mowers…

      1. That’s exactly what I want! I would have prefered if it had been made by someone not connected to a specific battery, but this is cool too. Hopefully it makes a resurgence.

    1. Consider trying propane. Much cleaner burning, you don’t have to mess with the ‘no-drip’ gas cans, no waiting for expensive batteries to charge, etc. I’m aiming to do it to a riding mower I was recently given

    2. It’s a lot of energy to deliver with batteries without getting to a price point people don’t really associate with lawn care equipment. 5 years ago, I shopped for mowers to cut my 1-acre lot. Ryobi had one with the necessary endurance, but it cost $7000.

      Edit: Hey, looks like you can get one for about half that now! I still would take my $1200 used Husqvarna zero turn.

      1. I’m watching this space closely too. I have to mow about 5 acres, so I’ve accepted that an expensive machine is necessary, but if I can avoid the hassles of small engines it would be awesome.

        1. This is the line of thinking that got me a DeWalt string trimmer, which I love.

          The 23 (I think) horsepower 2-cylinder on my mower has crossed the threshold from small to medium, in my opinion, and it shows in the almost zero maintenance I’ve put into it since buying it. It even uses spin-on oil filters. For 5 acres you’re likely even farther over that line.

          1. Yeah I have an Ego trimmer and chainsaw, which have both been extremely trouble free for several years.

            My mower is a semi-commercial 61″ Husky with a 27 hp Briggs twin. It’s been a good unit so far, but I like the idea of electric power being both simpler and cleaner. I see Ego now has a 52″ unit that can supposedly mow 4 acres on a charge so they are getting closer to what I need.

            1. I wonder if it’s quiet enough to avoid earmuffs too? It took me a few months to connect the ringing in my ears to running that mower without ear protection.

              1. I would think so.

                I do want some longer term data on battery life in the mower application before dropping $6-7000 on one though. That would be an expensive pack to replace.

    3. There is a guy up in Canada who sells kits to convert box store garden tractors to electric power. His name is Brian Edmonds, I believe. I converted an old Craftsman tractor I bought off of CL about 5 years ago. I’m not going to lie and say it was an easy or cheap project, but it was worth it. It’s quiet, no exhaust or gasoline fumes, and it’s reliable.

    4. The batteries actually aren’t hard to DIY with a few tools and some practice. I’ve gotten literally thousands of dollars of batteries out of the recycling bins, fixed many of them, and stripped out the cells from the rest to build my own packs. I’ve made a couple ebikes just because I had to do something with all the Ryobi 49V batteries I had laying around with no tools.

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