Abstract: A vehicle seat belt retractor has a belt sensitive mechanism with a pawl which is thrown outwardly when a flywheel lags relative to the main shaft to engage an internally toothed wheel. The toothed wheel is received in a coaxial cup member having arms for engaging a lockbar which can engage ratchet wheels fast with the shaft to lock the reel. A spring between radial projections on the toothed wheel and the cup member maintains this in a predetermined angular relation and absorbs movement of the toothed wheel in excess of what is required to operate the lockbar. A pendulum can engage an externally toothed wheel on excessive retractor acceleration to hold this against rotation with the shaft and a resiliently flexible arm extending between this wheel and the flywheel then effects locking by retarding the flywheel. The arm permits the rotation of the flywheel to exceed that of the rotation of the externally toothed wheel.