How to Fix a Flat Bike Tire
Mark Helms, from GIANT Bikes, talks about how to properly air up your bike before your ride. Be prepared at the trailhead with a floor pump to make life easy and efficient. Mark carries the Control Tower 1 floor pump from GIANT.
Control Tower 1
How to Fix a Flat Bike Tire
The freedom of riding a bicycle is an amazing feeling and no one likes it when your joy ride is halted by a flat tire. Getting a flat tire is an inevitable part of riding a bike whether you're riding road, mountain, or at the skatepark. Fixing a flat tire is an easy task with the right tools handy, and with a little know-how and practice you can become a flat tire changing wizard! We're here to break down the basics of flat tire repair to better prepare you for the next time a flat tire strikes.
When out on a bike ride be sure to carry the bare minimum when it comes to flat repair. The following list will keep you covered, and prevent a flat tire from ending your next epic ride.
- Spare Tube(s)
- Repair Kit
- Tire Levers
- Bike Pump
- C02 inflator w/ cartridges
Five Steps to Fixing a Flat Bike Tire
1. Remove the Wheel From the Bike
If you have rim brakes you will need to release the brakes in order to remove the wheel from the bike. V-brakes will require you to squeeze the brake arms together to release the tension, allowing the cable to be released. While some brakes feature a quick release lever to allow the wheel removal with more ease. Then using either the quick release skewer, or by loosening the bolts with a wrench, you can remove the front tire for repair.
The rear wheel requires slightly more effort as one must manage the chain, derailleurs, crankset, and cassette. Begin by shifting your rear derailleur into the smallest cog. Apply pressure to the rear derailleur in order to release the chain from the cog. Now the rear wheel is free to be pulled out of the rear dropouts of the bicycle frame.
Be careful not to contaminate the disc brake rotors when changing your tires. Avoid contact with hands, liquids, and debris.
2. Remove the Inner Tube from the Tire
First step in removing the inner tube is to deflate the tire entirely. Depending on the valve type this process is slightly different. Schrader valves require pressure to the pin found in the center of the valve while Presta valves need to be loosened and then depressed to deflate. Now that the tire is deflated we need to unseat the tire bead from the rim, which is the edge of the tire that fits into the groove of the rim. To unseat the tire bead push the tire bead edge toward the center of the rim with either your hands or tire levers. It's best to start from the side opposite of the valve stem to avoid damage to the valve. When you've unseated a portion of the tire bead you should be able to work your way around the tire to complete the unseating process. Remove the inflatable tube from in between the tire and rim by pulling the valve stem out through the rim first. Slow and smooth will help prevent and damage to the inner tube or valve.
3. Identify and Remove the Cause of the Flat
Now to find the cause of this whole situation, find the source of the flat. Inspect the tire and tube for punctures, tears, or cuts. With the inner tube removed it's crucial to clear the tire of any debris that would subsequently cause another flat on a fresh innertube if installed without removal of the issue. If the tire looks clear, next step is to inspect the tube to find the site of damage. If the damage is not obvious you can inflate the tube to check for escapin air; holding the tube close to your face/ear can help identify small leaks. If all else fails submerge the inflated tube in water and look for air bubbles. In addition check the valve for quality as well as the spokes for any protruding ends that could be causing leaks.
4. Patch or Replace the Tube
To repair or to replace, that is the question? The choice is yours, and often there is no right or wrong answer. The situation can call for a quick swap, or a sufficient patch depending on your schedule and the equipment on hand. Simply swapping a new inner tube in is the quickest method for recovering from a flat, and many riders will swap tubes out on the route and wait till they get home to effectively patch the compromised tube. Alternatively other riders carry patch kits and will take the time to revive a popped inner tube mid-ride. A tube should be replaced and not repaired when the damage is too severe to patch, when a patch job fails to hole, or when a valve is damaged.
How to Repair a Damaged Tube
- Find the damaged area.
- Clean and dry the damaged area.
- Use sandpaper to create abrasion on the surface of the damaged area, this helps the glue adhere to the tube.
- Spread the glue over the damage and allow it to become tacky.
- Apply the tube patch and hold it in place with pressure.
Now that the tube issue has been solved it is time to remount the tire to the wheel and get your bike rolling again. Partially inflate your inner tube to give it shape and verify it is holding air. With one of the wire bead edges inside the rim you can now insert the valve stem into the valve hold of the rim. Ensure the valve stem is straight and not at an awkward angle, then work the rest of the tube into the tire. Starting from the point opposite of the valve stem work the wire bead inside the rim. It's most effective to work the bead in both directions at the same time, towards the valve stem. A tire lever can be helpful in completing the tire seat, however use caution to not pinch the inner tube with the lever. With the tire mounted, inspect the edges of the tire/rim contact area for the possibility of the inner tube being caught between the rim and the tire bead, this can cause a pinch flat. Slowly inflate the tire, watching both side of the tire bead to ensure a effective seat. It can help to massage the tire from both sides at a lower pressure prior to fully inflating to ensure the inner tube is installed correctly. Now the tire can be inflated to the recommended PSI.
5. Reinstall the Wheel
It's easiest to install the rear wheel with the bike flipped over, sitting on its handlebars and saddle. Position the rear wheel so the chain is draped over the smallest cog on the rear cassette. Now line up the axle of the wheel with your frame dropouts and lower the axle into place while simultaneously pulling the derailleur backwards to allow room to seat the axle. While holding the quick release lever in place, tighten the nut on the drive side of the bike. Close the lever and ensure it's tucked out of the way and not in contact with the frame. The final checkover would be to ensure the brakes are connected/aligned, the pedals spin, and the gears shift smoothly. Now it's time to get back on the ride!
Check out this awesome video from our friends at Park Tool that breaks down flat tire fixing. This video will give you a basic overview of how to repair a flat tire on a bike, including how to remove the wheel, replace the inner tube, and put it all back together.