2. Brace the wheel as you hold open the valve and work your way around the tire with your other hand, squeezing as much air out as you can. As the tube is deflating, push the tire beads (A) off the rim shelves (B) toward the center and into the rim well (C).
3. Push the valve partially through the rim.
4. Using both hands—together, fingers facing away from you—grip the section of tire opposite the valve and lift the bike wheels so that its weight pulls down and makes lifting the bike wheels off easier. Pull (roll) the tire toward you, using your thumbs as levers to lift and push up on the tire. Leave your dominant hand in place to keep upward pressure on the tire and, with your other, work around the circumference, squeezing it to guide the beads toward the center of the rim. This creates slack in the tire, allowing you to rest the bike wheel on the ground and, with both hands at the top, lift, push and/or roll the tire over the side of the rim to remove it.
THINNER RIM STRIPS LEAVE MORE ROOM TO WORK, WHILE THICKER ONES INCREASE THE INNER-BIKE WHEELS DIAMETER AND MAKE THE JOB HARDER.
5. Take out the tube and run a balled-up glove along the inside of the tire, in both directions, to snag anything sharp that may have caused the flat. Remove the intruder.
6. Put one bead of the inspected tire back onto the wheel.
7. Inflate your new or re-paired tube just enough so It holds its shape. Carefully luck the tube inside the tire and onto the rim, making sure the valve sits straight in the valve hole.
8. With the loose tire bead facing up, use your thumbs to push about 4 inches of the bead, opposite the valve, onto the rim. Moving your hands in opposite directions, work your way around the bike wheels, installing the bead until your hands are 6 inches from the valve on either side or the tire starts to resist. If the tube slips out between the bead and the rim, tuck it back in.
9. Rest the bike wheels, at the mounted portion of the tire, on your knee for support. Use one hand to apply pressure on that part of the tire and the other to work your way around, squeezing it and pushing the beads toward the center (again, this creates slack and eases installation). Push up on the valve and let the air out of the tube to create even more slack. Using the heel of your hand, not your thumbs, coax the last part of the tire onto the rim.
10. Inflate the tire, reinstall the bike wheels and ride.