Flat tires seem to happen at the worst times; but it doesn’t have to ruin your day or prevent you from starting or continuing your ride. The best way to prevent a bad ride experience is to be prepared! Every bike should have a saddle bag and in it should be a tube, multi tool, tire lever, pump, and tire boot. Links are included for my personal favorite ride kit.
First things first, if the bike has been sitting for an extended period of time, tires may just need to be filled. Tubes leak air, even the new ones, so if they are flat don't assume they are bad. Fill them up, if they hold air overnight you’re probably good.
So, you’ve filled the tire and it doesn’t hold the air. Now you know you have a hole but what to do next? Patch it or completely replace the tube.? Replace the tube! Patches are great if you don’t have a tube and need to get back on the road, but it is a temporary fix. If you need to patch, then use the park tool patches they never let me down. If your tire has a hole in it, replace the tire. If you’re on the road or trail and in a pinch, use a tire boot to cover the hole so the new tube won’t sneak out the hole and blow under pressure.
First thing you will need are a set of quality tire levers NEVER A SCREWDRIVER! I recommend Pedros tire levers because they are tough and less prone to snapping under load. If you don’t have a set of plastic levers, use what you have on hand that will allow you to pry the tire bead from the rim. Use extreme caution when reinstalling the new tube because it is easy to puncture the new tube.
Take the wheel off the bicycle by either loosening the bolts of the axle or opening the quick release lever. Typical axle bolts require a 15mm wrench, but an adjustable wrench will do. Avoid vice grips, channel locks, or anything with a toothed jaw as those tools will strip the flats of the bolt. If your bicycle has V brakes then the cable needs to be removed and the brake opened up. This allows the tire to fit past the brake pads when you install the wheel. Most road bikes will have a side pull caliper brake with a little lever that can be flipped and that will allow a fully inflated tire to easily pass through the pads.
Now you have the wheel off, use the tire lever and slip the smooth end of the lever under where the tire meets the rim. I usually twist or fold the tire to the opposite side of the rim to help loosen the metal bead of the tire and make a little room for the lever to fit under the tire bead. Once the lever is under the metal bead, push the lever all the way around the rim to free up or “unzip” the tire. Once you have one side freed from the rim, some tires will allow you to simply push the other tire bead over the rim; but if it is tight, use the lever and pry it off as necessary.
Tire is off. Great! If you can leave the tube in place inflate the tube with a pump (my go-to pump is the Topeak Joe Blow, it’s an affordable work horse that will last for years) and try and find the hole, this will make it easier if there is something small stuck in the tire. Now that you found the hole, inspect the tire near that location to see if there is road debris that needs to be removed. If you can’t find the hole, leave the tube in place within the tire, remove the tube and run your fingers through tire gently to feel if anything is still stuck in the tire (go slow the object is probably sharp ). Make sure to run your fingers through a few times in both directions, little metal wire has a tendency to lay flat and can easily be missed if your fingers run “with the grain.” Turn the tire around and run your fingers through again and you may find what you missed the first time. Be extremely thorough, visually inspect the tire and feel through every inch until you are confident there is nothing left in the tire. If you inflate your new tube without checking the tire you will most likely have two flat tubes.
Make sure to also check the rubber rim strip that protects the inner tube from the heads of the spoke nipples. If the rubbr rim strip looks old and worn out change it. if you are in a pinch and do not have rim strips laying around a few layers of electrical tape will do the job.
The tire is clear, great! Now check the tire again!! I can’t stress that enough.
Now, inflate new inner tube a little to give it shape and make it easier to install into the tire. I typically align the valve stem with the pressure stamp on the tire, this makes it easier to find how much pressure the tire needs the next time you inflate it.
With your tube lightly inflated fit it into the tire before mounting the tire on the rim. Pass the valve through the valve stem hole in the wheel and work one side of the tire onto the rim; start with the far side of the tire opposite the valve. Avoid using any tools to install the tire, try to pry the tire onto the rim using your hands as much as possible. If the tire is too tight, then use a tire lever but be careful it is easy to put a hole in the tube at this point. Make sure the tube isn’t getting pinched or sticking outside the rim and tire while you work the tire on all the way around. Install the wheel in the bike frame then pump up the tire. On some bikes you will not be able to get the inflated tire past the caliper brake; so it is best practice to install the wheel then inflate. Watch the tire as you inflate to make sure the bead is seated properly, if the tire starts to come off the rim let the air out fast to avoid blowing out a good tube.
Tire is on. tighten all the bolts or quick release, make sure the wheel is centered in the drop outs, and go ride!