How to fix a flat

So, my friend, Johnny Rollerfeet asked me if it was hard to change a flat on a bike. This is what I passed:

Flats are crazy easy.

1. Go buy a new tube and tire levers. There are some great ones now – wide and stiff, not the crappy ones that break. Actually, buy two or three tubes. They’re cheap, and I’ll guarantee you ruin at least one while changing a tire. Maybe not this time, but eventually. Plus, it’s always great to be the person on a ride with a spare tire.
2. Take the wheel off the bike. Look at the tire. See if you can find what caused the flat – thorn, piece of glass, pinch flat from hitting the curb without enough air in the tire. If you can find something in the tire, pull it out. Mark the hole, if possible
3. Lever off half of the tire – wedge two levers under the bead, pry with both of them until the bead comes over the rim. Slide one lever along between the sidewall and the rim until enough of the tire is off to remove the rest by hand.
4. Pull the old tube out. Keep track of it’s orientation.
5. Reinflate the tube to find where the hole was. If it corresponds to anything found and removed, you’re good. If not, check inside the tire, starting where the hole in the tube is. Don’t get completely freaked out if you don’t find anything – especially with glass, it’ll pop out as the tire goes flat.

(note on re-reading this – you can leave one bead of the tire inside the rim. If you’re really paranoid, though, pop off the other bead and turn the tire inside-out to really inspect for junk)

6. If you’re at home, dust the tube with talcum powder. The tire’s probably already coated. On the road, don’t sweat it.
7. Partially inflate the new tube. Like one pump. Put the stem in first, then work all the way around the wheel. Make sure that the tube is all the way inside the rim.
8. Work the bead back into the rim, starting at the stem and working both sides around the wheel. End up opposite from the stem – this way, there’s not tension on the stem from putting in the tube. As you work in the bead, make sure that the tube doesn’t get between the rim and the tire – nothing more frustrating than starting to pump and then hear the tube pop ’cause it was pinched between the bead and the rim. This is the main reason to put air in the tube before you put it on. Too much air, though, and the tube’s too big to get the tire bead back into the rim. Just enough to keep it round.
9. The last bit of the bead will be tough. Stick one tire lever in to hold the bead, and with the other, pry the bead back over the rim. This’ll take a couple of tries, and is where most tire levers get broken.
10. Check the bead and the rim. Make sure there’s no tube there.
11. Reinflate the tire. About 25 psig, you should hear a ‘pop’ as the bead seats. Listen for leaks.
12. Take the pressure all the way up. Bounce it a couple times. Feel good ’cause you’ve fixed something with your own two hands.

It’s pretty easy – I tried to write good documentation. It’ll probably take 10-20 minutes your first time; I can do it on a ride in about 3, especially when it’s obvious what caused the flat. Fixing a flat’s pretty much a mandatory thing to be able to do on your own.

Keep the rubber side down.