Fixing a flat tire on an ebike can be a bit of a pain, especially if the flat tire is in a hub motor wheel. The best method is to try and avoid flat tires to begin with, but if you’ve already found yourself stuck with a flat tire, here’s how to fix it.
Remove the Rear Flat Tire
1. Make sure the bike is turned off, consider removing the battery pack. If you’re replacing a tire on the rear wheel, shift to the highest gear so that the chain is farthest away from the hub.
2. Consider putting the bike in a stand or flip it upside down so it rests on the handlebars and seat(consider laying down a blanket first to keep from scratching your seat, rack, handlebars, etc.)
3. Locate and disconnect the motor cable. The cable is located along the chainstays.
4. Remove the rubber cap that sits over the bolt holding the wheel to the frame.
5. Take an allen key and loose the derailleur hanger bolt, and pull the derailleur down and out of the way.
6. On the opposite side of the hub, take an allen key and unscrew the two bolts holding the brake assembly in place. Remove the brake assembly and let it hang off to the side.
7. Remove both axle nuts. Use a wrench to remove both axle nuts
8. Gently lift and remove the wheel. If the rear wheel is difficult to remove, rock the wheel back and forth while lifting.
Replace the Flat Tire
1. If the tire isn’t flat, you may need to take out excess air from the inner tube.
2. Massage the tire and prepare to remove it using tire levers. Set the wheel up in a way where you can push the tire lever up underneath the tire bead; then push the lever around the edge of the rim until the tire bead is no longer on the inside of the rim. Repeat the process on the other side of the wheel, the tire will likely be even easier to remove from the rim. Be careful not damage the tire.
3. Remove the tube from the rim and tire. Inspect the tube, tire, and rim, then identify where the leak took place.
4. Locate and partially inflate the replacement tube. Inflate it enough that it has a tubular shape to it.
5. Install the tire and inner tube on the rim. Seat one side of the tire bead on the rim and work the inner tube into the tire. Then, press the valve into the rim. Once the tube is inserted correctly inside the tire you can start to put the other side of the tire onto the rim. Check both sides to make sure that they are mounted properly and there isn’t any tube sticking out.
6. Inflating the tire to the recommended PSI on the tire sidewall, and reinstall the wheel.
7. Make sure that the axle is tight, and that the wheel is spinning smoothly before riding.