Way back in 2022, I bought a Trek frame for $80 and built a nice e-bike using a Voilamart brushless, gearless 1000w motor.
Then over the years I built other e-bikes and basically relegated the bargain Trek frame to the dust bin. However, as e-bike builders soon discover, we have many spare parts lying around which could end up being part of a new ‘rat’ e-bike. And in this case, my ‘reborn’ creation is being called Frankie since it is truly a Frankenstein bike, brought back from the dead, using bits and pieces from several previous builds.
Here’s my starting point for this (re)build:
Then to get started I needed a few new items. And with a budget of $200 for new parts for the complete build I have so far spent ~$165. I’ll include a list of recycled and new parts below once the build is complete, but so far this is looking like a very inexpensive build (because I already own all the expensive stuff – frame, motor, wheels, brakes, front fork, battery, etc.).
Stay tuned as this build comes together…
PS – For simplicity (and expense), I’m starting out with a 14-tooth single-speed sprocket, tensioner and chain salvaged from my Red Rocket experiment. This might not last since all I need to buy is a new derailleur to go from single- to 7-speed, which is desirable for PA hills. But since I still own Red Rocket, having a single-speed in the stable seems like a good idea. Also, unlike Red Rocket, Frankie will have PAS. Again, one of the real benefits of DIY e-bikes is being able to try something, then improve/fix it as needed!
** update **
One of the more daunting parts of e-bike building and wire and cable management. With my Frankie build nearing 80% compete, here’s what I mean:
Cables, cables everywhere. What to do?
With a good storage bag and a bit of persuasion, this wire explosion finally looked like this:
Not bad! The controller and all wires find their final resting place here. I still need to connect and tuck the rear motor wires in once I get my bottom bracket and deal with chain alignment for the single-speed sprocket. After that, everything needs adjusting, tightening, then testing. There’s still some distance to run before this race is over, but just to show that real progress is being made, here’s this morning’s update (still at $165 for new parts – I’m very happy about that!):
It’s October 4 and behold my creation!
My only compromise was the omission of PAS. Turns out to get the proper chain alignment I had to resort to a bottom bracket (116mm) that doesn’t have sufficient left-side clearance for the PAS hardware. But based on the way I intend to use this bike, that’s really a non-issue. This is a bike first with throttle assist.
I have yet to take this one out for a test ride but will report how I feel about riding a single-speed versus gears.
** update **
This e-bike is amazing! No, I’m not converting my other bikes to single-speed because gears are useful, though “not necessary when you have enough power”. Yes, you can quote me on that point. Here’s how I justify it. When riding with gears (and a motor of course), you shift to maintain pedal cadence. This just makes sense and works well for e-bikes. But take away the option to sift gears and you maintain speed and cadence by adding power via the motor. It works and it’s actually fairly natural once you adapt.
And just to refresh your memory, here’s a picture of my Single-Speed Chain Tensioner installed:
** update **
Final cost: $189.74
Here’s a list of new items required to complete this build:
- Bottom Bracket 12
- Headset bearings 10
- Rear disc brake adapter 19
- Handlebar 25
- Adjustable stem 20
- Grips 9.50
- Seat post 14
- Seat post quick release 8
- Front wheel true 15
- Tires 40
- Cell phone holder 6.50
And many of the items I already had on hand that made this build so cost effective:
Frame, battery, motor and rear wheel, controller and display, controller bag, front wheel, tubes, rim strips and FlatOut, brake discs, calipers and cables, front fork, brake levers, crank, chain ring and pedals, single freewheel, tensioner and single-speed chain, center stand, fenders, seat, mirror, and bell. I’m sure there’s more, but that seems like a pretty good list to start with. I still can’t believe I had this much usable gear hanging around in boxes! Impressive…