EIGHT STEPS TO A PERFECT INNER-TUBE SWAP
Make sure the tube is completely deflated. Insert your tire lever at the opposite end of the valve stem and flip the bead over the rim while keeping the lever inserted. You only need one lever. With the wheel in your left hand and braced against the ground, push the lever around the circumference of the rim. The bead will peel right over the rim’s edge. Most of the time you can leave the tire half on the wheel and pull the tube out. Check the tire for any cuts, holes or bead damage. Go around the entire circumference of the tire both inside and out. If you don’t, you could get a second flat minutes after your repair. There might be a hole somewhere in the tire that allows the tube to protrude. Or a piece of glass might have worked its way under the tire. Inspect the wheel’s rim as well – damage there could also be the culprit. The rim tape is also very important – make sure it is in good condition. If you removed the tire completely, install one side of the bead onto the rim. Always make sure the tire is facing the right direction (look for a direction indicator on the side) and place the tire logo over the valve stem. Install the tube and inflate it slightly so it takes shape. Begin from the opposite end of the valve and work the bead over the rim with both hands until you are close to the valve. Try to use your palms and hand to get most of the tire on. Only use a lever if necessary. If you avoid using a tire lever, then you lessen the chance of pinching the tube. Before inflating, always check that the tube is inserted fully in the tire by moving it back and forth.
Nick Di Cristofaro contributes to Canadian Cycling Magazine.
Remove the tire bead with tire levers
Check to ensure the tube is seated in the tire and not between the rim and the tire bead
Install the new or patched tube into the open side of the tire
Inflate tire to desired pressure
Remove the flat tube from within the tire
Inspect the tire inside and out for punctures or debris