Ahh, the cyclist’s oldest enemy. Not cars, rain, or roads with tiny shoulders, but flat bike tires. While the single flat tire can be enough to ruin a ride for those unskilled in repairs, there’s no reason for such a common and mundane problem to put a stop to your adventuring. Flat bike tire fixes are quite simple and require very few tools, allowing you to get back to shredding some road!
What you’ll need:
A replacement bike tube or tube patch kit
A bike pump
Tire levers (A nice thick plastic set are probably under $10 at your local bike shop).
Possibly (though usually not) a replacement tire
Step zero: Understanding how bicycle tires work
Bicycle tires come in three main types: tubular, tubeless, and clincher. While each tire type has its own unique structure and uses, chances are that if you’re reading this tutorial, you’re working on a clincher. Therefore, this tutorial will focus on how to fix a flat with clincher tires.
There are three distinct parts to a clincher tire setup: the metal or carbon wheel of the bicycle, the tire, which attaches the wheel with metal beads, and the tube, which is the part that actually inflates. The tube is “clinched” between the tire and the wheel, meaning it is so concealed that unless you’ve previously worked on a bicycle, you’ve probably never even seen it. If you have a flat tire, about nine times out of ten you only need to replace the tube (costing at most $5 for a replacement) as opposed to the whole tire ($40+ for a quality replacement).
Step one: Double checking the tube
Before you start taking anything apart, use the pump to try and inflate your tire. It may sound silly or redundant, but even as an experienced mechanic, I have all too often taken off tires and tubes only to find that nothing actually needed to be replaced, the tube simply needed reinflation. Usually pumping by itself won’t work, which means that your tire is actually flat and needs fixing, but it’s always worth a try!
Step two: Loosening the tire
Insert the rounded side of a tire lever underneath the edge of the tire. Push down on the other end of the lever to pry the edge of the tire away from the rim of the wheel. When pushed up and pulled out slightly, the stiff bead of the tire should pop over the rim to the outside. If the tire is loose enough, sliding the tire lever around the wheel should remove the entirety of the tire’s bead. If the tire is particularly tight, however, you may need to insert a second tire lever in the same position, then hold one while you drag the other around to loosen the whole tire. When one side of the tire is completely removed from the rim, the loose bead should hang down over the edge of the wheel.
Step three: Removing the tube
Rotate the wheel until the valve (the metal part that you attach the pump to) is in front of you. If the valve has a washer screwed onto the stem holding it in place, unscrew the washer and remove it. Next, push the valve towards the wheel with your fingers, causing it to recede into the rim. Reach underneath the tire and find a soft, rubbery surface. That’s the tube! Grab onto it and pull the valve through the wheel, popping part of the tube out from under the tire. Work the rest of the tube out from underneath the tire, pulling it completely clear from the wheel and tire. While removing the tube, make sure to keep it “lined up” with the way it was oriented inside the wheel. This will be important for finding holes in the next step.
Step four: Determining the cause of the flat
Once the tube is removed from the wheel, re-inflate it with the pump. If the tube has a hole, you should hear the sound of quickly escaping air. Find the hole where air is escaping, and cover it with your finger to identify if the tube has other holes. Repeat this procedure until you have found all holes in the tube. Once you know where the holes are on the tube, match them up to the corresponding location inside your partially-removed tire. Bend the tire back to get a good view inside of it, and feel around with your fingers to determine possible sources of a flat. Anything that caused a flat should be fairly obvious; look for things like tiny shards of glass or small nails. If something is stuck through your tire, you need only remove it. Except in extreme cases, the tire will repair itself around the hole and does not need to be replaced. It is also useful at this point to do a general check of the inside of your tire for any other excess debris and remove it.
Step five: Replacing/patching the tube
There are two ways to move forward with fixing a flat; you can either patch the holes in your old tube, or use a new, fresh tube for your wheel. Whenever possible, this guide recommends a complete tube replacement. Tubes are only nominally more expensive than patches and glue, and patching is only intended to be a temporary fix anyway; patches often will only properly cover a hole for a week or two of regular riding. If you do decide to patch your tube however, use the instructions specific to your patch kit, then follow along with the steps presented here for those using a new tube.
Step six: Inserting the new tube
Before inserting your new tube, partially inflate it. Usually two or three hard pumps with a hand pump will do well; if you have a reliable pressure meter, aim for around 10 or 15 psi. This slight inflation will prevent the tube from accidentally becoming pinched between the rim and the tire during insertion. Next, find the valve on your tube, and insert it into the corresponding hole in your wheel. Proceed to work your hands around the wheel, stuffing the tube beneath the tire, back into the wheel’s rim. Ensure that all of the tube makes it completely under the tire, leaving none to get pinched between the tire and the rim.
Step seven: Re-inserting the tire
Now that the tube is in place, it is time to re-insert the bead of the tire inside the wheel’s rim. With tighter-fitted tires, especially on road bike wheels with narrow widths, this is often the hardest part of the job. Begin adjacent to the location of the valve, holding the top of the tire with your fingers and using your thumbs to push the tire’s bead back inside the rim. Move your hands away from each other, around the circumference of the tire, inserting more and more of the tire as you go. When you reach the opposite side of the wheel, the task of pushing the bead back inside may become so difficult that you can no longer use your fingers. Try your very hardest to finish the job with your hands, as using tire levers at this stage can risk pinching the tube, but if necessary you can use your tools once again. If a tire lever is needed, insert the same end used to remove the tire, except this time upside down between the bead of the tire that is still outside the rim and the rim itself. Use leverage off the rim to pry the tire’s bead upward and onto the wheel, being cautious to avoid pinching the tube.
Step eight: Finishing up
With the tire fully back on the wheel, run your fingers around the wheel one more time, in between the rim and the tire, to ensure that the tube is not pinched between them. Once you are sure everything is in its place, inflate the tire! If your tube flats again, you’ll need to repeat the process, this time being more careful about checking your tire for debris and avoiding tube pinching. Most of the time though, you should be set to go!