How to Mend a Puncture in a Bike Tire



Nothing will wreck a bike ride faster than a flat tire, but fixing a puncture can be a snap, with a little elbow grease and some common tools and products.

Steps   [edit]

  1. Fairly obvious puncture...
    Fairly obvious puncture...
    Locate the cause and size of the puncture. If the tire is blown out, or has a large hole, it will have to be replaced. If you rode it through a patch of thorns, it may have dozens of holes, but if it is a single small puncture, for instance a nail, often it can be fixed on the bike.
  2. Place bike upside down
    Place bike upside down
    Turn the bike over so it is standing on the seat and handlebars. Make sure it is not on the brake levers or the gear shifter. A block of wood may be needed to support it off of these items.
  3. Spin the tire slowly. Look for anything sticking out of the tire, such as a nail, a piece of wire, a screw, or any other object.
  4. Let the remaining air out of the tube. You may want to invest in a tire valve tool, but a matchstick, or ink pen can be used to depress the shrader valve stem to do this. The valve stem is the small round piece of metal underneath the plastic cap where air is put into the tire.
  5. Pry the tire off the rim. Push a dull flat blade (common) screwdriver between the tire bead and the rim, and pry the edge of the tire off the rim. You will need to pry the tire loose around the rim, about an inch or two (2.5 cm - 5 cm) apart, until the tire becomes loose enough to pull free on one side.
  6. Lift the tube out of the tire. Be careful not to rip the valve stem off. The tube should be hanging between the rim and the frame, so if it is a back wheel, don't let it become entangled with the gears or chain.
  7. Pump enough air into the tube to inflate it sufficiently to find the leak. A bike tube will double or triple its original diameter, and the more air, the more the leaking hole will expand, making it easier to find it.
  8. Look around the tube
    Look around the tube
    Look around the tube for a small hole. Feel and listen for air escaping.
  9. Mark it
    Mark it
    Mark the location of the hole when you find it. Remove the air from the tube once more.
  10. Buff the area where you will install your patch. Most patch kits come with a small metal rasp to do this.
  11. Spread a thin layer of glue around the puncture site. Allow it to dry until the liquid gloss disappears.
  12. Patch it
    Patch it
    Peel the plastic backing from the patch. Be careful not to touch the sticky adhesive surface, and place the sticky side on the tube, pressing it firmly into place. You will need to use one hand to hold the back of the tube to press hard enough to get the patch to seal.
  13. Slide the tube back into the tire. Be sure that the valve stem is aligned with the hole in the rim it sticks out of.
  14. Pry the tire back onto the rim with your screwdriver. Take care not to push the point in enough to pinch the tube.
  15. Reinflate the tire. Put away the tools and finish your ride.


Tips   [edit]

  • Remove the wheel only when you have to because the different types of gears, chains, brakes, and other components can make this a difficult project. There are some pictorial representations in the external links.
  • Assemble an emergency kit for your bike before going on any long outings. The items in this kit should fit easily in a small bum bag or saddle bag, and weigh less than five pounds. The emergency kit should include:

    • a small air pump
    • a pair of pliers
    • a tube patch kit
    • a screwdriver
    • an adjustable wrench.
  • There are amazing products on the market to reseal and inflate tires without dismounting the tire or wheel. "Slime" is a gooey gel that is injected into the tire valve. Note, however, that when using it, you must still have a pump to reinflate the tire. "Fix-a-flat" is an aerosol can with latex rubber and a compressed propellant that instantly inflates tires, but it is a high pressure and sometimes combustible mixture, so it is more suitable for much larger tires. If you use it, be extremely careful and only use it in a well-ventilated area clear of combustible materials.
  • Keep out of the way of traffic and people - remove your bike from the street, sidewalk, or bike path to implement your repairs.


Warnings   [edit]

  • Never attempt repairs in dense areas of traffic or in other dangerous situations, including on a bike path. Push your disabled bike to safety before attempting any repair work. You will be too engrossed in repairing to notice oncoming cars, bicyclists and roller-bladers.


Things You'll Need   [edit]

  • Small portable air pump
  • Tube patch kit
  • Screwdriver
  • Valve stem tool (optional, but handy, cheap, and small)