An electric bike is much easier to put together than you think! All you need is a well-maintained bike, a conversion kit, and a battery. Using a kit makes this process even easier and faster. If you manage to buy the kit online (to get the best deal) and reuse a bike you already own, this can be a fairly inexpensive project.
Steps
Part 1 of 3: Gather the Materials

Step 1. Choose a mountain bike with front disc brakes and wide handlebars
If you do not own a bicycle, you can search online or in your locality to get a second-hand at a good price. Fortunately, you can use almost any bike you have on hand, although certain features provide the best results:
- Choose a bike with 26, 20, or 16-inch (66, 50, or 40 cm) wheels, as these are the most common sizes available on the market. Smaller wheels are typically found on folding bikes that accelerate faster, are more uneven, and are less efficient at cruising speed.
- Mountain bikes often become electric bikes, although you can use a different type as long as it has a sturdy frame and standard bottom bracket. Avoid riding a bike with a carbon fiber frame or forks, as these are not strong enough to handle the extra weight or handle the extra torque.
- The widest handlebars are the best as they give you plenty of room for all accessories and lights.
- The front disc brakes will help you stop more easily on steep slopes.

Step 2. Find an electric bike conversion kit
If you've never built an electric bike before, a conversion kit will make the process much easier. These bolt-on kits contain a throttle, a speed controller, and a wheel with a motor attached to the hub. Some also come with indicators, monitors, and brake levers, although these items are not strictly necessary.
- Make sure the kit comes with a wheel the same size as the existing wheels on the bike! It is much easier to replace the front wheel than the rear, due to the position of the gears, so you can opt for a kit in which the motor attached to the hub is located on the front wheel.
- In most cases, the battery does not come with the conversion kit. However, for ease of installation, it is best to purchase both the battery and the conversion kit from the same manufacturer.

Step 3. Choose a 36 or 48 volt battery with a 10 or 20 Ah capacity
Choose a battery designed for use in an electric bike, as it will come with a charger and will be much easier to install. Make sure the battery voltage and capacity you choose are compatible with the conversion kit you purchased. The higher the battery voltage, the more powerful the bike will be. When building an electric bike, you should choose a 36 or 48 volt battery to gain speed and comfort.
The capacity of the battery will define its duration. If you plan to take short trips, a 10 Ah battery will suit you, while a 20 Ah battery will provide additional capacity for slightly longer trips
Part 2 of 3: Replace the wheel

Step 1. Remove the wheel that you need to replace
Start by opening the rim or cantilever brake with the lever (if applicable). If your bike has disc brakes, you should remove the retaining pin or bolt or the clips or springs that hold the pads in place. Remove the pills with a needle nose pliers and set them aside.
- To remove the front wheel, you must turn the bike upside down so that it sits on the seat and the handlebars. Then, turn the quick release lever to the "open" position. Lastly, simply lift the front wheel off the bike.
- To remove the rear wheel, crouch behind the bike. Hold the frame with your non-dominant hand and use your dominant hand to pull the derailleur back. Then lift the frame off the rear wheel with your non-dominant hand and unhook the chain with your dominant hand.

Step 2. Transfer the tire and tube from the old wheel to the new one
Let the air out of the old tire and use a removable to separate the tire from the wheel. You must remove both the tire and the tube. Reverse the procedure for installing the tire and tube on the wheel that came with the conversion kit.

Step 3. Place the wheel with the electric hub on the bike and connect the brake components
You simply have to reverse the procedure you followed to remove the wheel to reinstall it. Make sure to adjust the chain to fit properly if you plan to replace the rear wheel. If your bike has rim or cantilever brakes, simply lock them over the new wheel using the detachable one. If your bike has disc brakes, put the pads back in place and secure them with the retaining clips, springs, cotter pins, or bolts.
Adjust the brakes as needed, either by aligning the calipers (for mechanical brakes) or pumping the lever (for hydraulic brakes)
Part 3 of 3: Add the other electrical parts

Step 1. Connect the speed controller and throttle
Follow the instructions in the conversion kit to install both pieces using the included tool. Use the bolts provided to secure the speed controller to the bike frame above the chain. Then connect the throttle to the handlebar so it's easy to reach.
If you have other accessories, connect them too. Secure the speed sensor to the rear wheel and connect the monitors and gauges to the handlebar with the included tool

Step 2. Connect the battery to the speed controller and throttle
Follow the instructions included in the kit to connect each piece. Usually you just need to plug the speed controller connector into the battery connector and then repeat the procedure for the throttle. Be sure not to bundle the battery cables together, as this could create a dangerous spark!

Step 3. Install the battery on the bike
Most electric bike batteries are designed to fit into the frame instead of the bottle holder. This is considered the ideal location, as it keeps the center of gravity low. Use the included tool to connect the battery to the frame as instructed in the provided instructions.
Another alternative could be to place the battery in a box or basket on the front or rear of the bike, especially if it is too large to fit properly in the frame (for example, if it has more than 60 volts)

Step 4. Secure loose cables
Use zip ties to secure the loose parts to the frame. Keep safety in mind, as you don't want any cables to get caught while driving.

Step 5. Ride your electric bike
That is all! Now you can ride your new bike. Just lightly press the accelerator when you're ready to drive. Take a test drive in a less populated area to get used to it before taking it out on the road.

Step 6. Charge the bike when necessary
An electric bike battery comes with a charger, which makes this procedure much easier. Follow the instructions to connect the battery to the charger and plug it into a compatible outlet whenever necessary.
Advice
- Strong acceleration drains battery power faster, especially from a standstill.
- You can also add a mid-drive motor to build an electric bike, although this option is more expensive and much more complicated.