Bicycle maintenance | 9 MIN READ

How to fix a flat bicycle tire

Changing a bike tire might not seem like an especially important life skill, but if you ride a bike in any capacity, it’s a skill you should learn. No one ever plans on having their ride interrupted with a flat tire, but flat tires are one of those annoyances that every rider has the displeasure of experiencing at one point or another. By thinking ahead and taking some time to learn how to change a flat, the hassle of having to change a tire remains just that: an annoying interruption, but not the end of your ride.

If you want to successfully change your bike tire, then before even learning the “how” of it, you first need to know and collect the “what.”

In other words, you need to be prepared, which means having a fix-a-flat kit that you take with you on each ride. At the very least, you should include the basic materials required to effectively fix your flat; what you’ll need will depend on whether you’re riding tubeless or tubed.

Tires with tubes

  • mini pump, preferably with a hose
  • CO2 cartridge(s), a minimum of two is recommended - just in case
  • inner tube(s), a minimum of two is recommended - just in case
  • valve extension, especially if you’re riding aero rims
  • tire levers
  • tube patch kit

Tubeless tires

  • mini pump, preferably with a hose
  • CO2 cartridge(s), a minimum of two is recommended - just in case
  • tire levers
  • tubeless tire repair kit
  • inner tube - just in case

tubed vs tubeless tires

Putting together a fix-a-flat kit might seem like an afterthought, but having one on hand might be the difference between a minor disruption to a ride and a major aggravation. If you end up with a flat, remember - always find a safe place, away from traffic and other possible dangers, before working on your bike.

1. Remove the wheel from the bike

The first step in changing a flat tire might seem obvious, but here it goes: remove the wheel.

If your tires are tubeless and you have a tubeless repair kit, then you might be able to skip this step. If the damage to the tire is a simple puncture, you can just plug it without taking the wheel off. However, if you find that the damage to the tire is extensive enough to where plugging it won’t resolve the issue, then the wheel will need to be removed. To remove the wheel from your bike, start by flipping it upside down.

Pro tip: You might find it easier to work on your bike when it’s upside-down. When flipping your bike, remove the computer from the handlebars to avoid scratching it.

removing back wheel

Removing the rear wheel might seem intimidating at first, particularly when you realize that the chain and derailleur are located in the rear. However, the process of removing the back wheel isn’t much more difficult than removing the front, especially if you take your time. To begin, first shift the bike into the smallest sprocket, creating slack in the chain for easier wheel removal and installation. Raise the bike by the saddle and while pedaling with your hand, use the right shift lever to shift gears. Repeat this, using the left shift lever, so that the chain ends up on the smallest chainring in the front as well.

While typical wheel removal requires that you open the brake if you’re addressing a flat tire, then it’s likely that the tire has already lost enough air so that it slides out easily. If your bike is equipped with disc brakes, then you’re in luck because the wheels can be removed without touching the brakes. Quick releases that hold the wheel in place are especially common. To loosen the wheel via quick release, pull - do not twist - the lever out and away from the frame until it is completely open. You should be able to remove the wheel with ease by carefully lifting the bike by its saddle and letting the wheel fall out. If it doesn’t fall on its own, hitting it with the palm of your hand gently should be enough to make it drop. If it still doesn’t come out, then check to make sure the chain and derailleur aren’t stopping it. If they are, lift your bike by its saddle and, while holding it up, reach around with your other hand to pull back the derailleur and consequently, the chain. Some derailleurs are equipped with a clutch, requiring that you release the clutch and then remove the axle. Push the derailleur cage towards the crank and let the wheel drop. At no point should you find yourself trying to force anything to move.

2. Remove/plug the tire

Once the wheel has been removed, it’s time to address the tire itself.

Standard tires are designed with an inner tube, which is inflated with air. While relatively inexpensive to replace, making them a popular option, tubes can be punctured or pinched flat relatively easily. Tubeless tires don’t have an inner tube and are instead equipped with an airtight rim that the tire snuggly rests in.

If you’re running tube, then you’ll need to remove it; if you’re running tubeless, you’ll need to patch it with a tire plug. Tire plug kits are sold at most reputable bike shops and consist of a strips of rubber and an insertion device, requiring no other equipment or changing out hardware. Most tubed tires can be converted to tubeless.

remove the tire

To remove the tire, you’ll need to use your tire levers. To do so, insert the flat end of the lever under the bead. Place a second lever under the bead and move along the rim until the tire is off. In most situations, you can reinstall the replacement or a patched tube without completely removing the tire. By breaking the bead on just one side, you will save a lot of time and greatly simplify the process.

3. Determine cause of flat

While many would recommend you run your finger along the tire to search for the culprit of your flat, doing so could also result in you having to do some patchwork on your finger, too. If whatever punctured your tire is still there and it’s capable of piercing a bike tire, then your finger stands no chance against it. Before doing a hands-on analysis of the problem, visually inspect the tire, both inside and out, first. It might take longer, but you’ll be able to avoid a finger cut and maybe even a tetanus shot. You can also pack cotton pads or use something else to create a barrier between your finger and the sharp object that it might encounter, but there’s still a risk of injury . Tire levers are used for the removal of tires, but you can also run one along the tire for inspection purposes if you prefer playing it safe.

If both the visual and tactile inspections fail, reinflate the tire to see if you can hear the air leaking out of the puncture point. If you find only one puncture hole, then you’re most likely looking at road debris as being the culprit. Depending on the location and manner in which your tire has been punctured, a pointed tool, such as a screwdriver, can be used to push out the object in question before it works itself inward and creates additional punctures. If you see two holes next to each other, then it’s likely that you’re dealing with a pinch-flat, which means your flat wasn’t caused by road or trail debris; it was caused when the tube got itself pinched between the tire and rim.

determine cause of flat

4. Patch the problem(if applicable)

Patching tubes is an excellent option for anyone who prefers pinching a few pennies, going green by reusing, or being resourceful when there are no more spares. Patch kits are available exactly for this purpose and come with everything you need need in order to get the job done. Patch kits also happen to be very compact so they are a perfect backup, even if you prefer to replace the tube outright.

If patching is your thing, then you’ll want to start by cleaning the affected area and then roughing the surface with an emery cloth or sandpaper. Kits come with two kinds of patches: glueless and those required glue. If your kit has glueless patches, then it’s basically like putting on a bandaid: peel off the backing, place it over the hole, and press with firm pressure. If your patches require glue, then simply add a thin layer of glue to both the tube and the patch. Once the glue has reached a tacky consistency, place the patch and press firmly until you’re sure it’s solidly in place.

There are some flats that are simply too severe to patch. In those circumstances, you’ll need to skip this step and simply install a new tube.

patching bicycle tire

5. Install new/patched tube

To install your tube, you’ll start by using your pump to inflate it just enough so that it obtains its form, making it easier for installation and reducing your chances of suffering a pinch-flat. Starting with the valve stem, put the tube on the rim and insert the stem straight through the valve hole. Carefully work the tire back onto the rim by rolling the bead away from yourself using your hands, not a lever; levers increase the likelihood of accidentally puncturing the replacement tube. Upon reaching the valve stem, wrap sides of the tire bead low into the rim and push up on the stem to get the tube into the tire.

Pro tip: if you align the branding on the tire with the stem, you’ll be able to locate the stem much quicker next time.

To avoid having to deal with another flat, it’s important that you take extra care to ensure that the tire bead isn’t pinching the tube. Do this by grabbing the tire with both hands and "massaging" and twisting it side-to-side as you work around the rim. This will ensure that the tube is positioned correctly inside the tire, away from the bead that can pinch it.

install new tube

6. Inflate the tire

Now is when you find out whether or not your efforts paid off; it’s time to inflate your tire. To do this, you can use either a CO2 cartridge, a minipump, or both. Each method of inflation has its pros and cons, so ultimately, choose what’s most comfortable for you. If possible, equip yourself with both.

CO2 cartridges are highly effective, especially when your goal is to inflate to higher pressures, but they are a one shot deal, so there’s no reusing them. It’s a good idea to practice tire inflation at home using a CO2 cartridge to ensure that when the inevitable occurs, you don’t blow out your tube or waste the cartridge, and get left stranded. The key to using a CO2 cartridge is to ensure that the inflator is properly connected to the valve stem.

Having a minipump in your arsenal is highly recommended so that you always have a backup method for tire inflation, even if it’s not as easy to use as CO2 cartridge. Having a pump with a hose is also strongly suggested because it allows you to push the pump against the ground for better leverage, allowing you to accomplish higher pressures; pumps that attach directly to the valve stem don’t offer this advantage and might cause damage to the valve stem or even the rim when used improperly. Combination mini pump/CO2 inflators are also available.

As you’re inflating to your desired PSI, double and triple check the bead so that you’re sure it’s sitting in the rim correctly. Only after you’re certain that everything is in its proper place should you reattach your wheel.

7. Install the wheel

Last but not least, it’s time to install the wheel. The processes of replacing the front and back wheels vary a bit, but neither is especially harder than the other, as long as you know how to effectively get the job done.

To attach the front wheel, first line up the fork dropouts with the axle of the wheel and gently lower the fork onto the axle. Carefully push down on the handlebar to check for the proper placement of the axle in the dropouts. It’s important to be mindful that the quick release or thru-axle lever is on the opposite side of the drivetrain and not touching the frame. Hold the quick release lever in place as you tighten the bolt. If you find that the lever closes too easily or ends up making contact with the frame, just open the lever and tighten the bolt a bit more. Be careful that you don’t over tighten the bolt, as it should be tightened just enough to allow you to use firm pressure when closing the quick lever. If your bike is equipped with rim brakes, don’t forget to reconnect, adjust, and check them for functionality.

reinstall back wheel

If your flat occurred on the rear wheel, then lay the top of the chain around the smallest cog on the cassette and make sure the frame dropouts line up with the axle. As you gently push the wheel back into the frame, take care to also pull the derailleur down and back so that it doesn’t get in the way. In the event that the wheel doesn’t go in easily, remove it and try again. If you’re sure that the wheel properly placed, then it’s time to close the quick release (and rim brakes if applicable) or insert the thru-axle into the frame and hub and thread it shut. The final test in determining whether your bike is ready to continue its journey is by lifting the rear wheel and spinning the cranks. If it runs smoothly, then you know you’re good to go.

Some useful tips and tricks

Flat tires are already unplanned and unexpected; planning ahead by prepping a fix-a-flat kit and learning how to change your tire can ease your mind for such unfortunate circumstances, but what do you do when even fixing your flat doesn’t go as planned? Read on for some quick, easy solutions when even flat tires don’t go your way.

Small, unfixable punctures. Super glue is already a life-saver in so many situations, so why should cycling prove to be any different? Super glue is a great quick fix for smaller punctures that might not be fixable otherwise, albeit temporary.

Large, unfixable punctures. If you find that you end up with a hole that’s simply too big to repair, then it’s time to resort to some out-of-the-box thinking. Cut out the damaged innertube section and tie the two ends together. It’ll be obvious to you that it’s not a perfect solution, but you should at least be able to reach about 50 psi, which is certainly enough until you can better resolve your tire situation.

Unfixable tire and sidewall gashes. In the event that your tire or the sidewall of your tire ends up sliced or gashed beyond standard repair, don’t despair; make a boot instead. Using a dollar bill, old gel wrapper, or piece of duct tape to cover the hole from the inside is a quick, easy way to resolve your emergency until you get home. It might not be ideal, but it should suffice until a more permanent resolution can be made.

Velosurance

Learning the skill of bike tire repair can be thought of as a form of insurance: you might not want it and you might never use it, but if ever find yourself in a situation where you need it, you’ll be glad it’s there. The folks at Velosurance are all cyclists and understand that it’s only a matter of time before an unfortunate circumstance arises. From gap medical to liability, vehicle contact protection to even roadside assistance - for when you’ve got a flat and are fresh out of options - Velosurance offers a highly customizable policy to provide coverage for nearly any cycling associate risk. Whatever your needs, chances are, there’s a policy for you.

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