Abstract: Air pumps particularly suitable for use with bicycles includes a first elongated tube to form a pump chamber and housing, a second elongated tube coupled with a piston in the first tube to reciprocate the piston within the pump chamber. A flexible hose extends from the piston and through the second tube and has at its exposed end an air valve coupling. The first and second tubes are releasably secured to permit use of the pump as a seat post. The pump includes a first valve on the outside of the piston between atmosphere and a closed end of the pump chamber and a second valve inside the piston between the closed end of the chamber and the flexible hose. The first valve is configured to provide greater seal effect as pressure builds in the closed end of the pump chamber.

Abstract: Theft of a bicycle is discouraged by a locking mechanism in the front headstem that controllably engages the handlebar-attached headstem with the front fork or disengages the headstem and fork for free relative rotation. A shaft attached to the fork and a sleeve attached to the handlebar clamp are connected at a locking junction which is rotatable as a whole in the front journal of the frame. A key operated cam moves a locking roller radially outwardly of the shaft to engage a receptacle in the sleeve for engagement or allows the roller to retract into an aperture for disengagement. The shaft and sleeve have complementary conical tapers axially positioned by a split conical bushing. A cylinder lock operates the cam via a key having a substantially tubular configuration with a uniquely configured axial end for positioning lock pins against axial spring pressure.