Insert the valve stem through the hole in the rim, and gradually work the tube onto the rim.This will give the tube a little bit of shape, making installation easier. With your mouth, blow air into the valve. Remove the cap from the valve on the replacement inner tube.Simply pull this from the hole in the rim. Again, the valve stem will be the last portion of the tube removed. Reach inside the tire, opposite the valve, and remove the inner tube from the tire.The first two levers will probably drop away from the tire. Insert the third, and final, lever on either side of the above pair, and slowly rotate the lever around the circumference of the tire bead.Insert a second tire lever beside the first lever, mirroring Step 4.

The stem will be the last portion of the inner tube removed from the wheel. Be sure and work opposite the valve stem. Insert the flat end of a tire lever beneath the bead of the tire and wrap the opposite, hooked end onto the nearest spoke.Elevate the rear wheel, and push it from behind to dislodge the axle from the frame.In this instance, no tools are required-simply open the release arm and loosen the nut on the other end. Newer models may feature an axle skewer with a quick-release. Use an adjustable wrench to loosen the rear wheel axle nuts.This will place the chain on the smallest rear sprocket and largest front chainring. Shift the chain to the outermost gear combination.In this example, we're going to walk you through changing a Mountain bike tire. If you're fixing the flat yourself, you will need an adjustable wrench (if your bike does not have a quick release), tire levers (set of three), and a replacement inner tube.

Bicycle flat tire repair