Fixing a Flat Tire
Drat! A flat!
If you ride a bike, flats happen.
There are plenty of little mistakes to make while fixing a flat tire (believe me, I’ve made most of them), so let’s start from the moment that you feel that softening tire, and see if we can’t do things the right way.
First of all, if you’re going to fix your tire while out on the road, you need some supplies: A spare tube, tire levers to pry the tire off of the rim, and a pump or CO2 inflator. If you don’t have all three items, then carry a cell phone and make sure you have a friend you can reach who happens to owe you a favor.
Notice that I didn’t mention a patch kit? Patch kits are for mending your tube in the comfort of your own home (you can use that patched tube as your spare next time out). If you commonly get multiple flats on a ride (and need a patch kit) it means that your tires stink, that you failed to find out what caused the original flat (or failed to fix it) or that you need to find a new route to work.
When you first sense that you have a flat, keep some things in mind: First, if you need to, you can ride on a flat tire for quite a ways without doing significant damage to your bike. Sure, you may ruin a tire or scrape up your rim, but that sure beats getting mugged or run over if you stop to change your flat in an inappropriate place. Second, when you do pull over, make sure you have a decent place to work. Don’t stop where you’ll be working in tall weeds, or other spots where you’re likely to loose the contents of your seat bag in the process. Try not to stop in front of a “Beware of Dog” sign, or on the edge of a busy roadway where you’re impeding traffic. Everyone with me?
Now, before flipping your bike upside down in the ditch and getting to work, close your waterbottle tops. A flat sucks, but running out of water in the wrong place on a hot day can be hazardous to your health.
I assume that you know how to work a quick release lever to get your wheels off. If this isn’t the case, try taking your wheels off a few times at home. Learning a new skill when you’re hungry, have cold fingers, or when it is too dark to see isn’t ideal.
Rim shoulders and a deep center trench
Now, before grabbing the tire levers, go to the valve and let all of the remaining air out of the tube. If just a little air lingers in your tube, this job will be quite a bit tougher. After letting the air out, go around the wheel and squeeze the sides of the tire together. This will push the tire bead off of the rim shoulders, and down into the channel that runs around the center of the rim. This little trick will give you enough slack that some tires will nearly fall off of the rim, and some impossibly tough tires will become a bit more manageable.
O.K. Now put one of your tire levers (using the spoon side) under the bead of the tire. This works best away from the valve area of the tire where there is more room. Pry the lever over and use the little hook end to secure it to a spoke. Take a second lever, and stick the spoon end under the tire bead right next to the first one. Pry the tire edge up and to the side just a little. See the tire bead come off the rim just a bit? The key to getting a stubborn tire off is to pry the bead just a tiny bit, then slide the lever sideways on the rim just a half-inch and pry at it again, repeating this action until it gets easy to slide the tool all the way around the rim.
Pry off just a little bit at a time
Once one side of the tire is off, pull the tube out from under the tire, leaving the valve sticking through the rim. Take your pump, or use just a little bit of your CO2 cartridge, and inflate the tube enough so that you can hear or feel where the air is leaking out. Since the valve is still in the rim, you can check out the tire in the area of the leak for the cause of the flat. If you find a piece of glass or other debris, run your fingers around the tire and check for other bits. Check the rim tape, and make sure that all of the spoke holes are all covered up.
If you have a cut in your tire bigger than a pencil point, you’ll need to put a “boot” or patch on the inside of the tire to keep the fresh innertube from pushing through the cut. A folded-up dollar bill or an energy gel packet will work pretty well as a tire boot.
Before you install the new tube, inflate it just enough so that the folds and creases disappear. Put the tube valve through the rim hole, and start tucking the innertube into the tire. Go all the way around the tire, tucking the tube into place, and then pulling the tire and tube over the top of the rim. Now you should be ready to pull the edge of the tire back up onto the rim. This is a job for your fingers alone. If you try using your tire lever to pry the tire back up onto the rim, you’ll just put a hole in your new tube. Just take it inch by inch, squeezing the tire up and onto the rim. If you work in small enough bites, even the toughest tire should cooperate.
Partially inflate the tire. Notice any wobbles or bulges in the tire? No? Go ahead and inflate it all of the way up, taking care not to break the valve in the midst of your athletic pumping. By pumping only part-way at the beginning, you have the chance to catch a mistake before full tire pressure pops the whole thing off of the rim and you have to start over.
Re-installing the wheel should be no problem if you paid attention when you initially removed it. Check to make sure the brakes work, and spin the pedals to get the chain and gears sorted out.
When you’re ready to get back on the road, take one last look around the ditch, and don’t ride off without grabbing all the stuff that you left scattered about.