Bicycle Repair: Changing a Flat Tire

As a bicycle owner, sooner or later you'll be changing a flat. You may be on the trail or going around the block. Flat tread may suddenly appear overnight, or while you're getting ready for the next ride.
 
In any case, you should already be familiar with instructions for changing a flat tire when the time comes. Obviously, if you're at home the task will be easier, as you'll have access to a more comfortable working space. On the road, you should always be prepared with a small kit that can keep you moving.
 

Before Changing a Flat: Know your Tire's Anatomy

Become familiar with the parts of your bike and the tire's anatomy. The main parts of a bike are:
  • bead: the tire's lip, which must be released before removal
  • rim: the edge that holds the tire lip and where the brakes "catch"
  • tire: the outer rubber piece
  • tube: the inner rubber part that holds air to inflate the tire
  • valve: attached to the tube; common types include Presta and Schrader
  • wheel: the metal component with spokes and hub.

Before you're faced with changing a flat on the road, practice making a fix at home. You'll master the basic concepts of a quick change in no time.

Different Types of Flats
Flat tires can occur in different ways, including:
  • blowouts: An incorrectly seated tire or loose bead can cause a rim blowout. Aging, worn tires can also become herniated.
  • large and small punctures: These may be repairable with a patch job, but could require a tube change.
  • multiple punctures: Never assume you're dealing with just one puncture. Inspect the tire and tube for other damage.
  • small leaks: These are difficult to locate. You can treat a leak by inflating and continuing the ride until you can locate the trouble at home or take the tire to a professional shop. You can also change the tube.

Bike Repair Kits for Changing a Flat

This basic repair kit will let you make fixes and changes quickly and easily.
  • frame pump or CO2 canister
  • patch kit (Look for those specifically geared for bicycle tires.)
  • spare tube (It's often easier to replace than repair a tube.)
  • tire levers, also called irons, are made of plastic and will save time, especially for novices (Exercise caution when using levers as they can easily pinch the tube.)
  • wrench for the axle nuts on wheels without a quick-release design. (Children's, single gear and internal hub bicycles often feature bolt-on wheels.)

Replace the glue in your patch kit every few months, as it can become dry. Also, if it's raining, you may not be able to make a patch repair. In that case, it's simply easier to replace the tube with a new one.

Safety Precautions for Changing a Flat
Once you've discovered a tire is bumping or losing air, stop riding. You could irreversibly damage the tire and the rim if you continue riding.
 
Before attempting to change a flat, find a safe place to work. You may have to walk the bike to reach a spot that keeps you away from dangerous traffic.

How to Change a Flat Tire

The fastest way to inspect bicycle tires is to rest the frame upside down on the seat and handlebars. When feeling for debris, go carefully to avoid injury from shards. If you find damage that is well away from the valve, you may be able to make a quick patch repair without entirely removing the tube. Use your levers to pull the tire away from the rim and simply pull out that portion of the tube.
 
Follow these instructions for changing a flat:
  1. Press on valve stem to release remaining air.
  2. Take off the wheel. It may be quick release or you'll need to remove the nuts. You may also need to unhook the brake cable from the pad (squeeze brakes and release the cable).
  3. Relax the tire from the rim with the levers (or irons). Angle the lever to unseat the bead and pull the tire over the rim and to the outside.
  4. Starting farthest away from the valve stem, gently remove the tube.
  5. Check the tire for damage also. Carefully feel inside for objects.
  6. Patch or select a new tube.
  7. Partially inflate the tube.
  8. Ease the tire back onto the wheel starting with the valve. Work equally from either side of the valve's rim insertion point until you reach the farthest point once again. You may have to use levers for the last few inches of replacement. Use caution to avoid pinching the tube.
  9. Place the wheel back on the frame. Be sure it's on straight and seated tightly.
  10. Inflate the tube, replace the valve cap and reconnect the braking cable.
After changing a tire, always ride cautiously for a distance to make sure the fix is working properly. You may also experience tire rubbing, meaning the wheel installation is incorrect. On occasion, air trapped between tube and tire can cause the appearance of a flat. Re-inflate and continue riding.
 
Resources
 
Bicyclesouth.com (2006). How to Change a Flat. Retrieved June 10, 2007, from the Bicycle South Web site.
 
Bicycleuniverse.info (n.d). How to Fix a Flat Tire. Retrieved June 10, 2007, from the Bicycle Universe Web site: http://bicycleuniverse.info/eqp/fixflat.html.
 
Kenkifer.com (2000-2003). How to Fix a Flat Tire on a Bicycle. Retrieved June 10, 2007, from the Ken Kifer Web site.