Nov 15, 2024

Converting a Bicycle to an E-Bike

Our community gifted every family a bicycle when they bought a house, which I thought was pretty cool. But then an idea struck me — most e-bikes out there cost over $200. What if I could upgrade our neighbors’ bikes into e-bikes for under $200? Not only would it be fun, but it might even help me gain some money for a PS5!

I found a very powerful (and budget-friendly) conversion kit on Temu that had all the essential parts for the transformation (except the battery) for just $74. Here’s what it looked like:

Next, I needed a battery. For a 24V 250W motor, the maximum output current is 10.4A. I looked for a 24V battery with a capacity of 30-50Ah to ensure at least 3 hours of ride time. After a lot of digging, I found an unbelievably cheap option on AliExpress — just $20 with free shipping!

With everything ready, I started the project using my girlfriend’s 24” mountain bike from Walmart:

The tricky part was adding an extra freewheel to the rear wheel to connect the motor. Since the bike’s gear system was already on the right side, I installed the new freewheel on the left.

The most time-consuming step was mounting the motor. It needed to fit snugly between the seat stay and chain stay while keeping its gear perfectly aligned with the freewheel. Let’s just say the bike maker and kit manufacturer didn’t have collaboration in mind. After some serious machining (and a bit of cursing), I made it work!

The final step was connecting the motor, throttle, battery, and controller. As a mechanical engineering PhD, this was a breeze! To keep everything safe from water, I placed the controller and battery in separate protective cases.

After testing, the motor ran smoothly. Mission accomplished! I transformed our regular bike into an e-bike for less than $100. Yay! 🎉

Written by JJ on Nov 15, 2024