Best DIY Ebike Front Hub Kit - Complete Installation of the Magic Pie 5

1 : Overview

This guide covers the complete step-by-step installation and setup of the Magic Pie 5 front hub motor kit (1000W peak 1500W) on a standard bicycle or tandem trike. The instructions apply equally to other motor power options (250W, 350W, 500W) with minor differences in power ratings. 

The kit includes everything needed for a clean, integrated electric front wheel setup:

Front hub motor with internal controller- Wiring harness

Brake levers with electric cut-off- Throttle (thumb or twist option)

Two-button switch for cruise control and optional horn

Mounting hardware including washers, nuts, and torque arms- Battery mounting cradle and hose clamps

 2 : Before You Start

Confirm your bike's front fork dropout width is 100 mm standard. This kit fits standard dropouts only.

The kit works with both rim brakes and disc brakes. No modifications required for either system.

Choose your throttle style (twist or thumb) according to your preference.

Have the necessary tools ready: socket wrench or drill with socket, Allen keys (5mm and 2.5mm), screwdriver.

3 : Step 1: Removing the Original Front Wheel and Brake Components 

1. Unhinge Rim Brake Wire (if applicable):   For rim brakes, release the brake cable by pressing down the small clip on the brake wire and sliding it out. This allows removal of the tire. 

2. Remove the Front Tire:   Using a socket wrench or drill, loosen the nuts on the front wheel axle. Remove the tire completely from the fork. 

3. Prepare Motor Wheel:  

Mount the tire onto the motorized rim.  

Ensure the motor wiring exits on the left side (non-drive side) of the bike to prevent reverse wheel rotation. 

Check the tire tread direction and install accordingly

4 : Step 2: Mounting the Motor Wheel on the Front Fork 

1. Insert the wheel axle into the fork dropouts (100 mm spacing). 

2. Place the 2 mm washers inside the fork dropouts on both sides to prevent side-to-side wobble. 

3. Use the tabbed washers with the tabs positioned on the top opening of the dropouts for extra safety against axle loosening. 

4. Secure the axle nuts tightly on both sides using your socket wrench  

5 : Step 3: Installing Torque Arm(s) 

Why Torque Arms? Standard bicycle forks are not designed to handle the high torque from hub motors. Torque arms prevent the axle from spinning inside the dropout, protecting your fork from damage and ensuring rider safety. 

Installation: 

1. Slide the torque arm onto the axle. 

2. Attach the torque arm firmly to the fork using the included screws and hose clamps. 

3. Use heat shrink tubing (included) on the clamps to protect the fork paint from scratching. 

4. For extra safety, especially on heavy or tandem bikes, install two torque arms-one on each side.

6 : Step 4: Replacing Brake Levers and Installing Throttle & Switch

1. Remove the original brake levers by loosening the screws and detaching brake cables. 

2. Install the new electric brake levers included in the kit, which have motor cut-off functionality. 

3. Mount the throttle on your preferred handlebar side (left or right). In this build, the throttle was installed on the left. 

4. Install the two-button switch (cruise control and horn) on the opposite side of the throttle, typically near the gear shifter. 

5. Tighten all screws and bolts with the correct Allen keys (5mm for brake levers, 2.5mm for throttle and switches)

7 : Step 5: Installing and Adjusting Brake Cables 

1. Insert the brake cables into the new electric brake levers the same way they were removed. 

2. Adjust brake cable tension to ensure effective braking without drag. 

3. Connect brake levers to the wiring harness to enable the motor cut-off function when braking.

8 : Step 6: Wiring the Motor Kit- The motor assembly has three main connections:  

1. Battery Power Cables (Red & White wires): Connect these to your battery pack, typically routed near the battery mounting location.  

2. 10-Pin Male Connector: Plugs into the main wiring harness that branches out to throttle, brake cut-offs, and switches.  

3. 5-Pin Male Connector: Used for Bluetooth or USB connection if you want to program or monitor the controller.

The wiring harness splits into four connectors:  

Two for the brake levers (left and right)  

One for the throttle  - One for the two-button switch 

Make sure all connectors are firmly plugged in and secured  

9 : Step 7: Mounting the Battery 

1. Determine battery placement-usually on the bike frame or rear rack. 

2. If your bike has water bottle mount screws, remove them to mount the battery cradle. 

3. If not, use the provided hose clamps to secure the battery cradle onto the frame tubing. 

4. Use the included screws and a 2.5mm hex key to fasten the cradle securely. 

5. Slide the battery pack into the cradle. 6. For thicker frame tubes, you may need larger hose clamps (not included)

10 : Step 8: Final Testing and Ride

Power on the system and test the throttle response with the bike stationary.

Test brake cut-off by squeezing brake levers while applying throttle; motor should immediately stop.- Perform a torque test without pedaling to verify motor power and responsiveness.

Pedal the bike without motor assist to check resistance; direct drive motors have minimal drag and are pedaling friendly.

Take the bike for a controlled ride to evaluate overall performance.  

11 : Performance Notes

On a tandem trike with two riders, the 1000W Magic Pie 5 motor achieved a throttle-only top speed of approximately 52 km/h (32 mph) on a 52V battery (not fully charged).

The motor can handle heavy loads; test runs included hauling approx. 600 lbs.

The motor supports future upgrades such as reverse gear installation, cycle analyst display, and pedal assist sensors.

Chapter 12 : Maintenance Tips

Regularly check the tightness of axle nuts and torque arms to ensure safety.

Inspect wiring harness connections for wear or looseness, especially after rides on rough terrain.

Keep battery contacts clean and dry.

Adjust brake cables as needed to maintain effective braking and motor cut-off function.