Fixing a Flat Tire

Flat Tire Fixin' Steps (a beginners guide)

Fixing Flats At the instigation of the evil and cold Dr. Schraedor, a quick beginners overview of some tire fixin' steps has been compiled. -WhiteZombie
If possible, mark the tire at the valve stem. This will make it easier to locate the thorn (?) that caused the flat once the tire is off.	Shift the bike into the highest gear (smallest cog on cassette) to make dismounting and remounting the chain easier.	And if your bike has V style brakes, unhook the cable to open the brakes.	Then swing open the quick release and remove the wheel.
Bicycle rims are a "dropped center" rim design. This means that the inside center circumference of the rim is smaller then the outside circumference where the tire bead sits. This dropped center is key to easy removal of the tire. By pushing one side (lets say the 6 o'clock position) of the tire's bead into the dropped center, enough slack is created to make prying the bead off the rim at the 12 o' clock position easy.	Before starting to pry the tire bead over the rim, push the bead down into the dropped center on the opposite side (6 o' clock) that you will be prying from.	While pushing the tire bead down into the dropped center at the 6 o' clock position, grab the tire at the 12 o' clock position and lift it away from the rim.	Then hook a finger under the bead. If you have a tire with very stiff sidewalls, you might want to substitute tire irons for fingers at this point.
When the finger is under the bead, slide it around the rim, lifting the bead as you go until the bead on one side of the tire is completely off.	You can now remove the valve nut (if you have a Presta valve tube) and push the valve up through the rim and remove the tube. To find the object that caused the flat, run your hand around the inside of the tire, feeling for a sharp object (usually a thorn). If you can not find it by feeling around, pump up the flat tube and reference the tube's puncture with the mark you made on the tire in step one. When\if you find a foreign object, remove it from the tire.	When the tube puncture is repaired or a new tube is roached from a riding partner, pump enough air into it (apprx 5 lbs.) so that it has shape. This will prevent the tube from being pinched between the rim and the tire bead when mounted.	Push the tube back into the tire all the way around the rim, push the valve stem back through the rim, making certain the valve stem is perpendicular to the rim (and then screw on the valve nut if Presta).
Then start pushing the tire bead down into the rim with both hands working out from the 12 o' clock position to the 6 o' clock position.	When pushing the tire bead down, your right hand will be working outward from the 12 o' clock position, 1, 2, 3, etc. to 6 o'clock. While your left hand is working 11, 10, 9, etc. to the 6 o' clock position. It might get a little difficult pushing the last bit of bead down into the rim at the 6 o' clock position. Just push the opposite side (12 o' clock) into the rim's dropped center to get some slack in the bead. When the tire is back on the rim, pump up the tube and listen for any hissing noises.	Slide the rear wheel back on the bike and push it all the way down into the dropouts. Then close the quick release.	Don't forget to hook your brake cable back on!