Repairing a flat rear tyre on a fat-tyre electric bicycle is one of the most common yet challenging maintenance tasks for e-bike owners.
Unlike standard bicycles, fat-tyre e-bikes are typically equipped with hub motors, torque arms, and thicker casings, all of which add complexity to what would otherwise be a straightforward wheel removal.
The first step in the repair process is preparation. The seatpost must be secured, and the gears shifted into the smallest sprocket to ease chain release.
After disconnecting the motor cable, the axle nuts and washers on the derailleur side are carefully removed, followed by loosening the torque arm. With the motor axle free, the rear wheel can be gently manoeuvred out of the frame.
Once removed, the old, often bald or punctured tyre is deflated and taken off the rim. Fat tyres may be removed by hand, but in some cases metal tyre levers are required.
A fresh tube is lightly pre-inflated to hold its shape, then fitted inside a new 20×4.0/4.5/5.0-inch tyre. Care is taken to align the valve straight and avoid pinching the tube during installation.
The tyre is then inflated gradually, ensuring the bead seats evenly on both sides of the rim. With correct pressure—generally around 30 psi—the wheel is reinstalled.
This involves aligning the disc rotor, securing the axle fully into the dropouts, tightening the torque arm, and reconnecting the motor cable.
Final checks include testing the gears, brakes, and pedal assist functions. When performed correctly, this repair restores both safety and ride comfort, extending the life of the e-bike while saving the rider from costly workshop visits.
