Beginner’s knowledge: Fix a flat

July 9, 2012 · 4 minute read

There a number of basic repairs that every mountain biker should know. However, the flat tire remains the Achilles heel of most beginner riders. There is a great quote that reads, “A bad attitude is like a flat tire…you can’t go anywhere ’til you fix it.” Anyone who has attempted to change a tire on a bike knows that it can lead to a bad attitude. Hopefully, following the steps below might help you figure out a system of changing your tires with less of a headache. More importantly, I hope it helps you get back on the trail quicker and with the peace of mind you need to keep the wheels rolling!

Before you get started, you will need a few tools. You will need a floor pump/hand pump (that fits either a Presta valve or Shrader valve), tire levers (also known as tire irons), a replacement tube (be sure to buy the correct wheel size and tube size), and a 15mm wrench (if your bike does not have a quick release). (Picture 2) Removing the rear wheel – this requires a few steps.  First, you will need to loosen the brake cable to enable getting the rear wheel out. Note: If you run disc brakes, this step is not necessary. (Picture 3)

Then you will need to flip the bike over so it is resting on the handlebars and seat.  For bikes with a quick release, pull the lever and gently loosen the quick release.  If you have bolt-on axles, you will need to use a 15mm wrench to loosen both bolts. (Picture 4)  In order to get the wheel off easier, use your left hand to ‘open up’ the rear derailleur.  You can do this by pushing on the back of the lower derailleur wheel with your thumb while simultaneously pulling the body of the derailleur.  You might have to practice this motion a few times to get the feel of it.  (Picture 6).  While you have the rear derailleur ‘opened up’, lift the rear wheel out with your other hand.  All right, now the hard part is over…your wheel is out!

Removing the blown tube – Be sure to let any remaining air out of the tube before trying to take out the tube.  First, pull the tire to one side using your hand to better access the lip of the tire.  Then, insert the ‘scooped’ end of the tire lever, catch the lip of the tire, and press the other end of the lever down until the tire lip ‘pops’ off the rim (picture 7).  Now, run the tire lever around the lip of the tire until one side of the tire is ‘unseated’ from the rim. (picture 8 ). Now, remove your blown tube.

Replacing tube – Note: it is best practice to run your hand gently on the inside of the tire in order to check for any debris or anything that might have punctured your tire.  Then, you will want to pump up the new tube just enough so it takes shape (picture 9).  Next, insert the new tube starting at the valve.  Make sure the valve goes in straight through the hole in the rim (picture 10).  Now you can begin to insert the rest of the tube and seat it inside the tire (picture 11).  Once the tube is in the tire, then you can begin to ‘seat’ the tire onto the rim.  Use your thumbs and broad part of the palm to push the tire back on the rim. Note:  in my experience, this is easiest when the wheel is lying on your lap to give you some leverage (picture 12).

Pump it up and reassemble – Now all you need to do is pump up the tire the rest of the way (picture 13). You will need to follow the steps in No. 1 in reverse order in order to get your wheel back on the bike. Don’t forget to connect your brake cable again before jumping on to ride!

 Hopefully, this brief explanation has helped and hasn’t further confused you. A great way to practice is to let the air out of a perfectly good tube and pretend it is flat. Practice all the steps until they are ingrained in your head. Once you know how to change a tire, then pack away the tools you need on your next ride so you never have to deal with the frustration of a flat tire again. (Picture 14)

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