You could be stranded if your bike gets a flat tire; but you have the possibility to change it yourself. Usually this just means replacing the tube that is inside the rim. However, you may need a new tire if the old one is badly damaged or worn. Before changing the tire, you must remove it. Then, put the tube and tire back in place, if necessary. Lastly, you need to put the rim on the wheel.
Steps
Part 1 of 4: Remove the wheel

Step 1. Lay the bike on its side with the chain facing up
You will not be able to remove a tire while the bike is in an upright position as it will topple over. The side of the chain (known as the drive side) must always point upward to avoid damage.
- You can also turn the bike upside down, resting it on the handlebars. Some people do not like to put the bike in this position because the handlebar (or seat) could be damaged.
- Alternatively, you can invest in a vertical stand to hold the bike while you work on it. You can get this item in some bike shops or online.

Step 2. Adjust the gears to the smallest ring if you are removing the rear tire
It is usually located on the outer gear. Installing the chain over this smaller gear will make it easier to remove the rear tire.
You do not need to adjust the gears if you are removing the front tire

Step 3. Open and remove the quick release lever, if your bike has one
You should look for this lever in the center of the bicycle wheel. Pull the lever up, and then turn it 180 degrees to loosen it. Remove the lever from the axle and set it aside.
- If the quick release lever does not release after turning it 180 degrees, you should continue turning it until you can remove it.
- If you are not sure how to remove the rim, it is best to consult the bicycle manual or the manufacturer's website.

Step 4. Use a wrench to loosen the nuts if you don't have a quick-release lever
You must hook the wrench into the nut and then turn it to loosen it. Keep turning the nut until it pops off. Remove the lug nuts from both sides of the bike.
- If you can't loosen the nut, you can spray it with all-purpose lubricant or cooking spray to make it easier to loosen it.
- A 15mm wrench is usually the right size to loosen the lug nuts on a bicycle.

Step 5. Disconnect the brake cables if necessary
In many cases, opening the quick-release lever also disengages the brakes. If your bike model does not have this feature, you can press the calipers on the brakes to release the cables.
You can check your bike's manual or the manufacturer's website if you're having trouble disengaging the brakes. Instructions may vary for each bike model

Step 6. Detach the wheel from the chassis
Remove the tire from the forked groove that supports it on the bike. You may need to move the bike tire slightly as you remove it.
If you are removing a rear tire, you will likely need to detach the chain from the bike
Part 2 of 4: Remove the tire and tube

Step 1. Deflate the tire completely
Loosen the cap on the air valve. If it comes off completely, you can set the lid aside. Let the air out using the proper procedure for your type of valve. In this way, you will facilitate its extraction.
- If your bike has a Schrader (American) valve, you can use a small tool (for example, a wrench) to push the plunger into the valve and release the air.
- If you have a Presta valve, you must unscrew and pull the valve cap to release the air.
- If you have a Dunlop valve, you must remove the cap and then pull the valve to release the air.

Step 2. Hook the rounded edge of a lever under the outer edge of the tire
With this procedure, you will open the edge of the rim to detach it from the chassis. Pull the other end of the lever toward the spokes. Then hook the other end of the lever onto the spoke of the wheel to hold the rim of the rim off.
- If you don't hook the other end of the lever onto a spoke, the tire will snap back into place and seal around the wheel again.
- The outer edge of a bicycle tire is known as a "trim."
- You can find inexpensive tire levers at bike shops, outdoor stores, or online.
- You can probably remove the tire with a spoon or screwdriver, but you could damage it.

Step 3. Pass a second lever to the right around the circumference of the tire
Insert another lever near the first one, and then push the wheel up. Move the lever to the right around the tire, pushing it up as you go. You should continue until the entire side is released from the chassis.

Step 4. Remove the inner tube from the rim
Insert your fingers under the side of the tire. Hold the camera and slide it out. Once you get to the air valve, you need to push it through the hole on the wheel frame. Then continue removing the camera.
You can dispose of or recycle the camera
Part 3 of 4: Insert a new camera

Step 1. Unroll the chamber and remove the dust cap, circlip, and valve cap
Unfold the camera carefully, making sure not to damage it. You will likely find a dust cap and snap ring over the air valve that you need to remove. Loosen or remove the air valve cover so you can inflate the tire.

Step 2. Slightly inflate the tube to keep its shape
By inflating the tire, you will avoid warping, bending, or twisting the tube as you install it. This procedure will facilitate the installation of the new camera.

Step 3. Examine the inside wall of the tire for punctures
Look for a sharp object that may have punctured the tire (for example, a nail, a thorn, or a piece of glass). You can use your eyes, a cloth, or the finger of a glove to check the surface of the tire.
- If you detect something stuck inside the tire, you should remove it if you plan to patch it.
- Don't put a new tube inside the rim without checking for holes first. If there is something (such as a thorn or a nail) stuck in the rim, it is likely to puncture the new tube.

Step 4. Place the tube inside the rim
Press the tube into the rim with your fingers. The tube should follow the shape of the rim. Make sure there are no knots, tangles, or kinks in the camera.
The entire tube must be inside the tire before continuing. If you have trouble inserting the camera all the way inside, you should remove it and start over. You may need to let some air out to help it hold its shape

Step 5. Buy a new set of tires only if you cannot repair it or if the treads are worn
You can usually repair a tire simply by changing the tube. However, the tire may need to be replaced if it is severely damaged. This could mean a tear or a large hole. You may also not be able to repair it if the treads are worn, if the tire is dry and rotten, or if it is too old. If this is the case, you can purchase a new set of tires at a local bike store or online.
- You must buy a set of wheels designed for your bike model. It is best that you request it from the manufacturer.
- The tires are sold folded in packages. Usually the package contains a pair of tires.
- You should always change both tires if you need to change only one. Otherwise they will run out of level and you risk one of them going flat, especially the older tire.
Part 4 of 4: Putting the tire back on the bike

Step 1. Insert the tire back onto the wheel on one side
Place the air valve in the corresponding hole. Then align the outer edge of one side with the wheel. Put the tire back in place along the chassis of the wheel.
- Check the tire for an arrow that tells you which direction the treads should be located. This is called the "direction of travel." If the tire has an arrow, you need to make sure it is facing forward. Some tires can go in any direction and not have this arrow.
- Avoid using tools to make the change, as you could damage or puncture the tire or tube. You just have to use your fingers.
- You should use this same procedure to place the rim on the chassis of the wheel, whether it is the old or a new one.

Step 2. Place the other side of the tire back onto the wheel frame
Make sure the tube is completely under the rim. Next, place your fingers on the side of the air valve and press the tire into place. You should work around the chassis of the wheel, pushing the rim into the chassis. Then it ends above the air valve, which will be the loosest part of the tire when it is on the chassis.
- Make sure there are no bulges on the rim, which could mean that the tube is crowded, twisted or compressed.
- You will likely have to use tire levers at the end of the process, but you must be very careful not to puncture the tube or tire.
- It can be very difficult to put the rim back on the wheel, especially if it is new. However, you can reattach it with your hands alone.

Step 3. Screw the circlip down over the air valve if you have one
Some cameras come with a safety ring that descends above the air valve. This is to keep the tube in place on the wheel. You should line up the circlip with the threads on the air valve and then screw it down.
If your bike's camera does not have a security ring, you can skip this step

Step 4. Inflate the tire to the proper pressure level
You can use a manual or electric air pump to inflate the tires. Put the pump on the air valve and then inflate the tires. Once the tires reach the proper pressure level, you should replace the air valve cap.
The proper pressure level should be indicated on the wall of the rim. You can also consult the bicycle manual or search for it on the internet

Step 5. Slide the wheel onto the bike and replace the lever or nuts
Thread the wheel into the forked slot that holds it in place. Then slide the lever or metal bar that holds the wheel in place. Tighten the easy-release lever or nuts with a wrench, if necessary. Close the easy-release lever, if your bike has one.
- If you have repaired the rear tire, you will need to lift the chain to reattach it.
- Check that the wheel turns freely.

Step 6. Reattach the brakes if they are still disengaged
Press the calipers again and slide the brakes into place. Squeeze the brakes to make sure they fit over the wheel.
Before riding the bike, you should check the brakes again to make sure they are in good working condition
Advice
- If you have trouble changing the tire, you can visit a local bike shop for help. There, they will show you how to carry out the procedure, although they may charge you a small commission.
- It is better to repair the tire on a flat surface.
- If you can, you should repair the tire inside to help keep the bike clean and make the job easier.
Warnings
- Never over inflate the inner tube, as you could cause the tire to blow out. You should examine the wall of the tire to verify the recommended pressure level.
- Keep the inner chamber away from hot objects. Heat can expand the chamber and even cause it to explode.
- When removing the tires, you must be very careful so that they do not bend. If you accidentally damage a part of your bike, you may need to repair or replace it.
- It is normal for tires and tubes to deteriorate over time. Bicycles kept indoors will likely need a tire change every 10-15 years, while bikes kept outdoors might need a tire change every 7 years.