A temporary patch to cover a large hole or cut in a tire. A boot does not need to be air-tight, but needs to be sufficiently strong and stiff to prevent the inner tube from bulging through the hole in the tire. Many things may be used to boot tires, including leather, currency, food wrappers, etc. Patches intended for tube patching will not usually do a good job, because they are stretchy and will blow through the hole just as an inner tube would.
The best material for boots is a piece cut from an old thin-tread tire, preferably a tubular. Many cyclists carry such a piece of tire for this purpose.
A boot does not need to be glued in place. It will be held in position by the pressure of the inner tube.
V brake bootAn accordion-like rubber sealing device to cover the connection where one part slides into another, preventing dirt from entering. This type of "boot" is commonly seen on the legs of suspensionforks, and on the cables of direct-pull cantilever brakes.
