Tire iron

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A tire iron (tyre iron in British English) is a specialized metal tool used in working with tires that have inner tubes.

Tire irons usually come in pairs and are used to pry the edge of a tire away from the wheel it has been mounted on. After one iron has pried a portion of the tire from its wheel, it is held in position while a second iron is applied further along the tire to pry more of the tire away from the wheel. This allows enough of the tire to be separated so that the first iron can be removed, and used again on the far side of the other iron. Alternating in this way, a person can work his way all the way around the tire to fully remove it from the wheel, in order to reach the tube that sits inside.

Tire irons have not been in common use for automobile tires since the shift to the use of tubeless tires in the late 1950s. The term is now often mistakenly used to refer to a lug wrench, which is included along with a spare tire and jack on most new cars. Bicycle tire irons are still in use for those tires which have a separate inner tube, and can have a hooked C-shape cut into one end of the iron so that it may be hooked on a bicycle spoke to hold it in place. These are, however, more often referred to by bicycle mechanics and enthusiasts as tire levers rather than irons, presumably because those used on bicycles are now often made from plastic instead of metal.

Due to their heaviness, tire irons also appear as weapons in many stories, including Going to See Georges by Glendon Swarthout and the Hardy Boys series.

[edit] Bicycle tire irons

Typical set of three metal tire levers (pencil for size comparison)

A tire lever is a tool for removing or replacing tires on wheel rims. It is sometimes called a tire iron, though this is less common when referring to bicycle tire levers, as they are often made of plastic, not metal.

Tire levers for bicycle tires have one end that is tapered and slightly curved. The other end is usually hooked so that it can be hooked around a spoke to keep the tire bead free of the rim at one point, allowing a second lever to be manipulated forward, progressively loosening a larger segment of the tire bead from the rim.

A common feature of tire levers is the lack of sharp edges. The slightest pinch of an inner tube by a lever can weaken or puncture it. It is good practice to examine a set of tire levers for any sharp edges and file them smooth and round. Classically tire levers were made of metal. However plastic ones are now manufactured which are even less sharp and less likely to puncture the tube. There are also some single lever varieties, which can be popped under the bead at one point then quickly pushed around the rim to pop the bead off.

Tire levers are not necessary or desirable in all cases. In many cases, the tire can be reinserted on the rim, and sometimes removed from the rim, without the use of tire levers. This reduces the chance of puncture caused by pinching the tube between the rim and the tire bead. Sometimes they are used to fit the tire back on, but this can be done without the levers.