Hydraulically-operated bicycle shifting system with positive pressure actuation

Abstract

A family of new bicycle shifting systems incorporate improved derailleur designs that are controlled by sealed hydraulic actuators. The shifting systems (i) a hydraulically-actuated, manually-powered front and rear derailleur shifting system, (ii) a hydraulically-actuated, power-assisted front and rear derailleur shifting system with manual control, and (iii) a hydraulically-actuated, power-assisted front and rear derailleur shifting system in which the shifting sequence for the rear derailleur is controlled automatically by pedal speed. Each of these shifting systems utilize a totally sealed, inclined linear shifting path. Environmental contaminants are prevented from entering any of the critical derailleur or control elements. The linear, inclined shifting path provides precise chain shifting, more uniform chain wrap on the rear bicycle drive sprockets, and lower chain and sprocket wear. Several different shifting control units are disclosed.

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