My next DIY project, a homebuilt electric bicycle built from salvaged parts...

Miscellaneous and Personal Stuff I Must Share
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Yes I know I could simply buy a premade electric bike (very expensive) or any number of electrification hubs (less expensive but still expensive) but I want to try to build something myself on the cheap with as many salvaged parts as possible, just to see if it can be done…

Step one; acquired a host bike…
It’s an “OFO” dockless city bike, OFO has gone out of business in the USA, and people are liquidating their bikes at insane prices, the bike I picked up is brand new, still has the foam padding on the handlebars and downtube…

they’re made by Kent, are a singlespeed with coasting hub, front and rear rim brakes, a dynamo powered LED front headlight and solar rear light, full fenders, solid rubber tires, and galvanized rustproof chain, a chaingard over the drivetrain, the rear wheel dropouts are horizontal, the rear locking mechanism is disabled and can be removed, i’m going to have fun tinkering with that too

they’re basically built to be abused, I purchased mine for a whopping $75, and even in it’s stock form, it’s a fun little commuter bike, very comfortable and easy pedaling, nice upright position

I have a couple ideas as to how to progress…

Easy/Cheating way, get one of those electric wheel kits, a good battery system, and call it done, probably the front wheel would be the easiest way

Cheating Level 2; replace both front AND rear with electrified wheels, making it an AWD e-bike :wink: (of course both wheels would be wired for maximum speed)

Homebrew/Cheap; salvage a motor from a cheap/broken electric appliance/power tool like a rechargeable electric chainsaw, something with good torque, and rig up a homebrew system that somehow taps into/drives off the crankset

Cheat 2 is very tempting, even though it’d be the most expensive option, an AWD Ebike is calling to me, somehow…

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An electric recumbent would be sweet.

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A reliable, high capacity battery will probably be your biggest headache.

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My next door neighbor had an electric bike. It was a motor that IIRC, spun at a fixed speed. When you pulled on a handle, similar to a brake lever, the motor would pivot down come in contact with the rear tire and cause it to spin. I have no idea if he made it himself or bought a kit or if it came from the store like that, but it worked well enough.

One of those 40V, 5Ah batteries used on lawnmowers would do well, I’d think.

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I’ve seen several YouTube videos on this sort of DIY project, but never tried it myself.

If you’re willing to use new rather than salvaged batteries… A lot of these projects use inexpensive lithium-ion 18650 cells (so called because they’re cylinders 18 mm in diameter and 65 mm in length). They cost about $2 or $3 each new if you shop around. That’s the same sort of cell used in Tesla’s model S and model X. An e-bike might use a dozen cells or so. The Tesla model S battery packs contain over 7000 cells. The Tesla 3 uses a different cell, the 21700 which is also used in some electric bikes.

If you’re determined to use salvaged batteries, I’ve seen a couple of videos where they used old laptop batteries. I know I have more of those lying around unused than any other rechargeable battery. I’m not sure how well they really work for that application though.

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Interesting.
I was just googling around looking at mid-mount motors for my old road bike. Top of the line motors and batteries were adding up to over $1000. That was self installed.

I vote for the front and back wheel option. :eek:. It seems that that setup would have inherent excitement as you try and control two separate wheels going at different speeds.

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Another potential option for the wheel hub motors would be to set one up as a drive wheel (rear wheel, as rear wheel drive is the only proper vehicle drive :wink: ), and set the other up as a dynamo/generator, in order to recover some energy into the battery, I know it won’t fully recover all the energy, due to frictional losses and the fact that perpetual energy/motion is a fiction, but it would put something back into the cells

since the bike uses a low bar style frame (kind of like a “girls” bike frame) for low stepover height and so it fits a wider range of heights, it has a lot of space available in the center of the frame, , in theory I could even mount a crank/gear motor system in as well, and make a TRImotor E-Bike :wink:

Think of the potential acceleration on a Trimoto E-bike…

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Y’know, a lotta guys would say that those bikes are perfect for hub motors. $139 for the motor kit and $40 for a couple NEW batteries and you will be on the road with a RELIABLE electrobike in a couple hours. You never want to use used batteries.

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I saw an electric recumbent a couple of weeks ago. It’s part of the invasion. Just sayin’…

Re the OP - a galvanised chain?? How does that work for a part that wears and stretches?

Single speed?? Solid rubber tyres??

And these guys have gone out of business, huh? :wink:

j

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I guess they were looking for the “minimal maintenance” angle with the tires and chain, these were bikes destined to be abused, so try to reduce/eliminate as many failure points as possible…

heck, a frame with horizontal dropouts alone is worth $75 to me, even if I end up stripping off all the parts and rebuild around the frame

I’m almost tempted to see if those fat tire rims would fit, i’ll probably have to find a way to adjust the rim brakes though

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This is what the bike looks like (minus the front basket)

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The bike looks very much like the ones that are ubiquitous to Copenhagen. A design meant to be used every day while wearing regular clothes. A great score for $75.

I might keep it simple and just use one hub motor, you’ll have a great bike.

You can get an old beater bike for your experiments…

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The other alternative is to buy a second one for $75… the guy selling them has a huge amount of them, he had around a dozen out front, and hundreds out behind his house…

very cool house BTW, he has a massive solar array that powers the entire house, and he has one of those fourth-gen prius plugins that he powers of the solar array

Now even though I loathe the bloody prius, even I have to admit it’s a darned good idea, as he’s generally charging it up for free, a purely electric only car would make more sense, but he’s in a rural area of a small town, so having the gasoline backup in the hybrid powertrain makes sense…

…his truck was a diesel though, looks like diesels and hybrids CAN co-exist peacefully :wink:

actually, the best option for me is to get the hub wheel for my existing multigear bike (Giant FCR3)

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What? A solution that doesn’t involve getting another bike? Inconceivable!

Please note that I actually have fewer bikes than ten years ago. And a goal for my recovery is to finish assembling my trike then mounting a hub motor.

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on further consideration, I think it’d make more sense to install the hub motor wheel on the OFO bike, and keep the gearie as is

there’s a very real possibility that I might end up getting a motorcycle soon as well, i’m selling my 14’ johnboat setup on letgo, and I am in a discussion with a guy who wants to do an equal trade for his 1999 Yamaha V-Star Classic 650, both are about equal in trade, and i’d get more use from a motorcycle anyway, he’s looking for a boat, so it looks like it’s going to work out

Glad I never let my motorcycle cert lapse…

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Where are all these new bikes for $75 ? Looking around I see 2018 warehouse sales in the DC area.
I’m familiar with the Plural Z Alpha area but not your sector.

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They’re in Fremont NH, bit of a drive/ride for you :wink:

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I don’t want to gloat, but… :smiley:

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Plans have changed yet again (it’s a technician thing, we have very mercurial interest swings…

Mom really loves the bike, and she’s been helping me through some rather daunting medical problems that are irrelavent to the thread, I can never hope to repay her for her help and kindness, so I think it’s only fair that I give her the bike, the e-bike project is put on temporary hold, i’ll definitely do it, but later, and use my Giant FCR3 as the host, as I already own it, and I don’t want to start hoarding bicycles

as far as a small in town runabout, I solved that issue today, I traded my 14’ johnboat rig and trailer straight across for a 1999 Yamaha V-Star 650 Classic cruiser motorcycle, it’s got around 25,000 miles or so, and is in pretty good condition for it’s age, came with slimline hard saddlebags, fairing, rear seat, and sissy bar (the accessories need to be installed), it’s solid, runs strong, and should get around 45 MPG (same as my Golf TDI), I have no plans to go on the highway, I’ve got the Golf for that, but it’ll be an in town runabout and backroad cruiser

Equal trade, and both of us were selling for the same price, he needed a boat, I needed a bike, it worked out perfectly :slight_smile:

i’ll eventually convert my bicycle to electric, but it’s on hold for now

….hmm, Tesla motor and battery pack in the Yamaha?..

No Russ, stop it, stop trying to tinker with EVERY new toy you acquire!

Technician Syndrome is an awfl(ly fun) affliction…:slight_smile:

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