Abstract: A bell assembly for inflating a tubeless tire on a wheel includes a first bell and a second bell slidably disposed within the first bell. The second bell includes a smaller diameter than the first bell. A shaft extends upwardly from the second bell in one of a relative to the first bell. A locking member is engagable with the shaft and is movable between a first locking position and a second locking position. The locking member secures the second bell in the first bell position when the locking member is disposed in the first locking position. The locking member secures the second bell in the second bell position when the locking member is disposed in the second locking position.