Step 3: replacing the inner tube
- Remove the damaged innertube
Once you've dislodged one side of the tyre from the wheel, remove the damaged innertube starting from the side opposite the valve. You can now start preparing the new innertube.
- Prepare the new innertube
Start by very slightly inflating the new tube, this will help it to keep its shape while you insert it into the tyre.
- Seat the tyre back on the rim
This process should be the opposite of how you took the tube out, so you start with the valve. As you roll the inner tube under the tyre, you should simultaneously sit the tyre back onto the rim. It may get a little difficult as you approach the last part of the tyre. At this point you may either persevere with your bare hands, or use your tyre levers.
*Note that using the tyre levers will increase the risk of you puncturing your tube by pinching it between the tyre and the rim.
- Re-inflate the tyre
If you're unsure of the pressure to pump your tyres to, just check the sides of the tyre. It should inform you of a minimum and maximum pressure.
While pumping the tyre up, it is a good idea to pause around 20psi to ensure that the innertube is not sticking out between the tyre and the rim. If it is, deflate the tyre and adjust it appropriately.
When you have reached the desired pressure, replace the valve camp and re-attach the wheel to the bicycle. Do not forget to close your brakes if you had to open them to remove the wheel earlier.