Bike Maintenance 101: How to Fix a Flat
Real talk, it’s not a matter of if you’ll get a flat but when. In fact, the difference between a 10-minute fix and walking your bike home hinges on whether you’re prepared for the inevitable. That’s why I made a step-by-step tutorial for fixing a flat that’ll save your ride someday.
Step 1: Removing the Wheel
Before you start looking for the culprit, you’ll need to remove the wheel from either the frame or fork. Depending on your bike, you’ll either have to loosen the quick-release and drop the wheel or remove the thru-axle and drop the wheel. We suggest learning these basics from the owner’s manual or a friend.
Step 2: Taking out the Tube
With the wheel removed, the next step is to pop one side of the tire’s bead hook off from one side of the rim. Popping the bead off of only one side of the rim will save you precious ride time, as you won’t have to wrestle the whole tire back on. Make sure that you remove any remaining air in your tube before you start, though.
To start, you’ll need a set (2-3) of tire levers to pop the bead off of the rim. Starting opposite of the valve stem, insert the tire levers approximately three-inches apart, as shown below.
Next, pull both tires levers towards yourself, popping off the section of bead between the levers.
With that section of bead removed from the rim, slide one of the tire levers all of the way around the rim to work the rest of the bead out. However, make sure to keep a hand on the stationary lever in order to prevent the bead from hopping back on.
Step 3: Finding the Cause of Your Flat
With the bead now completely removed from one side of the rim, pull the valve stem out of the rim and remove the tube (make sure to remember the orientation of the tube inside of the tire). Before dropping in another tube, you’ll need to find what caused your flat in the first place — you don’t want that rock or thorn still in your tire. If you can’t find it, your tube will inevitably flat again in the same spot.
To find the culprit, first inflate the tube and inspect it for damage. Generally, flats are caused by sharp debris, which will be visibly evidenced by either a slit or a tiny hole in the tube. Another, variation is a pinch flat. A pinch flat happens when the tube is “pinched” between the tire and rim. Usually, this kind of flat looks like a snakebite (as shown to the right). Once the damage on the tube is found, it’s time to inspect the tire for debris. And since you remembered the orientation of the tube inside of the rim (right?), it should be easy to find the issue. If you forgot, though, you can run your fingers along the inside of the tire. Safety note: take it easy; you don’t want to cut yourself on the debris that you just flatted on.
Step 4: To Replace or Repair?
My general rule of thumb is to always replace a tube, but if you’ve exhausted your supplies, you’ll need to patch up your tube in order to make it home. Patches work well, but a new tube provides a sense of security, relieving the mental stress of future issues like a slow leak.
Step 5: Installing the Tube
Whether you’re replacing or patching your tube, you’ll need to inflate it until it holds its shape (but no more) before trying to sneak it into the rim. Next, insert the valve stem and work the rest of the tube inside of the tire.
Step 6: Popping the Tire Back on
Once the tube is completely set in the tire, you can now start working the bead back onto the rim, starting opposite of the valve stem. Generally, I work my hands in a symmetrical manner around the rim until you get to the valve stem. Another option is to use the tire lever in the opposite manner of removal to pop the bead back on, but this method can result in a pinched tube; in general, try to avoid using tools to get your tire back on. It’s also important to note that the bead won’t want to stay seated, so keep your eyes on the section you’re not working. Now that most of the tire is seated you’re probably struggling a bit with the last 10%. The key here for tool-less installation is to roll the bead on to the rim, as shown below. If that doesn’t work, feel free to pop two tire levers in the last section, and flip the bead onto the rim in a similar fashion the first removal step.
Step 7: Inflating the Tire
Well, not quite yet. First, inspect the rim-to-tire interface to make sure there’s no bit of tube between the two (as shown to the right). If there is, inflation will either pinch and flat the tube or blow the tire off the rim during inflation. The ensuing explosion will shame you in front of all watching, so you’ll definitely want to make sure that doesn’t happen.