Tutorial: Changing a Flat

Presented by Scott’s Bicycle Centre, Cleveland, TN.

How to Change a Flat Tube

Tools

Gather the following tools:
New tube [make sure the tube matches the size (found on the side of the tire) and width of your tire, make sure the valve (Presta or Schraeder) matches the valve hole size in the rim]

2 tire levers (plastic; metal will ruin your rim)

Pump (floor pump or hand pump)

Special Considerations

Front Wheel: Remove wheel from the bike. If you have linear-pull brakes (“rim brakes”) you will need to disengage the brake before opening & loosening the quick release skewer and sliding the wheel out of the drop-outs. If you have a thru-axle, unscrew and remove the entire axle to remove the wheel from the bike. If you have hydraulic disc brakes, be careful not to squeeze the front brake level while the wheel is removed! Scroll down to step-by-step process.

Rear Wheel: Use the same considerations as above. To easily drop the rear wheel out of the drop-outs, shift the rear derailleur so that the chain is in the 2nd to hardest gear in the back. Using your hand, manually engage the rear derailleur while gently pulling the wheel off the frame of the bike. Again, using your hand, gently untangle the chain from the cassette. Scroll down to step-by-step process.

Step-by Step

1. Once your wheel is removed from the bike, you can begin removing the tire from the rim. Using the “scoop” side, gently slide one of your tire lever up and under the tire, grabbing onto the bead of the tire. Using the “hook” side, hook the tire lever (still scooping the tire bead off the rim) to the closest spoke.

2. Using your other tire lever, “scoop” up and under the tire again near the location of your other tire lever. Press the tire lever hard away from you, slowly removing the tire bead away from the rim. Follow all the way around the rim until half of your tire is off the rim.

3. Remove the damaged tube.

4. Using your hand and eyes, inspect the inside of the tire (feeling for thorns, holes, uneven patches, etc. that might cause another flat), the rim tape (looking for intact-ness and making sure spokes aren’t poking through).

5. Before placing your new tube on the rim, put a few pumps of air in the tube – just enough to give it a little shape. This will help you avoid twisting the tube or pinching it against the rim – both resulting in a blow-out.

6. Put the tube inside the tire on the rim; put the valve stem through the valve hole first (make sure it is lined up correctly – perfectly perpendicular to the rim), and work the tube in all the way around.

7. Using your hands start working the bead of the tire back onto the rim. Start at the valve stem, and work both hands sideways about half way, then flip the wheel over, and keep working until you can no longer use just your hands.

8. If necessary, use your “scoop” upside down to slide the bead of the tire back onto the rim completely.

9. Visually examine the tire, making sure you haven’t pinched the tube between the rim and the tire. After, start pumping air into the new tube.

10. Stop about 10-15lbs. of pressure into your pumping – using your hands, inspect the sides of the tire both to make sure there are no strange bulges and to ensure the tire is seated properly. Finish pumping the tire up to your desired amount of PSI (if you don’t know, check the side of your tire – it should have a min & max pressure… start in the middle of the two amounts and fine tune from there).