How To: Change a Flat on the Trail

By Carolyne Whelan,

Hammocks are a great way to relax during a long bike ride and are a perfect compliment to a bike tour or bikepacking adventure, because they are light and pack small, fitting well with most frame packs or panniers. Getting a flat tire can leave you hanging on the trail before you’re ready to hang out off the trail. Here’s a simple how-to for changing a flat on the trail.

 You’ll need:

  • tube* or patch kit
  • two tire levers
  • portable bike pump
  • possibly a 14m or 15m box/socket wrench, depending on wheel type. Most modern bicycle wheels have quick releases.

*A tube is easier to replace than to fix, so I recommend bringing a spare tube with you to replace, saving the punctured tube, and fixing it at home with the patch kit. At your local bike shop (LBS), you will need to find a tube that fits your tube in circumference, width, and valve style. A common road tube will have a circumference of 700c and a width of 23-25, with a presta (also known as “French”) valve. So the box will say “700×23 presta.” It may also say whether it is a long or regular valve, which you can tell by simply looking at your wheel. If you ride a mountain bike, there are more sizes involved as technology evolves. Whatever style and size your tire/tube is, it will say on the side of your tire. If you’re unsure, ask someone at your LBS for help. It will be wise to ask how to disengage and reengage your brakes as well, as you may need to do that to get your wheel out. For the patch kit, there are two types, ones with glue and ones without. The glue is messy, but it’s what works best. If you’ve never patched a tube before, the traditional patch with glue will save you a lot of time and frustration.

  1. Once you’re on the move and notice you have a flat tire, pull to the side of the bike trail, feel which tire is flat, and disengage your breaks (unless you have disc brakes) on that wheel. Turn your bike upside-down, so it’s resting on the handlebars and saddle. If the rear wheel has the flat tire, check to make sure you are in the hardest, smallest gear, and adjust accordingly. If you have a quick release, pull the lever out so the curve is facing you. Hold the bolt end and turn the lever until it loosens enough to take the wheel out. If it is the rear, pull up and back on the derailleur, allowing the wheel a bit of space to pop up. It may take a bit of wiggling the first time you do this, but it will come out fine.
  1. Put the curve of one tire lever into space between the rim (wheel) and the bead (tire) so that the curve of the lever can hook onto the bead. Place another tire lever about four inches away in the same manner. Push down on both levers so they lay flat against the wheel, near the spokes. The tire should pop out between the two levers. If not, try moving them a little closer and try again. Once a part of the tire pops out, slide one of the levers around the wheel, popping the rest of the bead out of the rim. If the tire lever won’t slide. Move the second tire lever to the other side of the first lever and repeat the process of popping out the bead, and try to slide the lever again.
  1. Once one of the beads is completely outside the rim, pull out the tube. Take your finger and carefully wipe along the entirety of the inside of the tire, where the tube was, to make sure nothing is stuck in the tire such as glass that will cause another puncture. Check the inside of the rim, also. There should be a rim strip in place to protect the tube from the spoke holes on the inside of the rim. If the spoke nipples (the tiny strews that attach the spokes to the rims) or spoke holes are exposed, adjust the rim strip so that they are all covered.
  1. Using your pump, put a bit of air in your new tube to give it shape. Place the tube’s valve in the rim’s valve hole. work side to side to tuck the tube into the tire. Once the tube is in the tire, use your hands to place the bead back in the rim, careful not to pinch the tube. If you come to a tight spot at the end, which should be opposite the valve, you can push on the tire on both sides of the valve, in a downards motion towards the tight spot. Try again to push the bead in, using your thumbs to push up. If that doesn’t work, use your handy tire levers to wedge that last bit in, and then move the tire back and forth in a rocking motion, to make sure the tube isn’t stuck under the bead.
  1. Pump up the tire! Your tire will tell you how many psi (pounds of pressure) your tire requires, and just like the tube, it will depend on what kind of bike you ride. If you have a little hand pump, it may take a while to get it up to full pressure.
  1. Put the wheel back in the drop outs. If it is the rear wheel, pull up the derailleur and place the wheel in the chain, so that the bottom is pressed against the cassette on the smallest ring. Tighten down the bolts of quick releases. If using a quick release, tighten it enough so it is a bit difficult to push the lever in, though not impossible to pull it out again in case you need to change another flat. Make sure the lever curves towards the frame.
  1. Turn your bike right-side-up, reengage the brakes, and pedal away!
carolynewheelerABOUT: Carolyne Whelan is an adventurer and freelance writer who usually hangs her hat in a camper. When she isn’t working as a bike mechanic in Pittsburgh, PA, she can be hard to locate without a compass but is most easily found at her blogs Lifting Weights at Midnight and Roadside Fires Burning. Her poetry can be found at carolynewhelan.com.