Abstract: A control device for shifting gears on a cycle wherein a hand lever is operational coupled by a semi-rigid control tie which is coupled to the transmission assembly at the hub. The transmission assembly with a link mechanism which is angularly pivoted by the control tie thereby moving a rack having two at least partly superposed pawls which engage notches in a rack which is coupled to a pin. The pin is slidable mounted so that the pawls can position the pin as required for shifting the chain guide. The extreme notches of the rack are partially obturated to prevent shifting above and below the proper sprocket prevent damage to the device.

Abstract: The speed gear device is particularly distinctive in that it includes a third movable fork side (11) mounted in a movable manner between the internal side (9a) and the external side (9b) of a fork (9) for guiding the chain (A) with a substantial spacing, in order to act in connection with the control means when the speed gear device is actuated, to guide the chain from a sprocket wheel to the other sprocket wheel.