Originally Posted by JohnDThompson

This is the issue that Simplex "retrofriction" levers and SunTour "Power" levers were designed to address. In the Simplex lever, a spring in the lever serves to counteract the derailleur's return spring so shifting against the derailleur's spring takes much less effort. The SunTour levers use a ratchet wheel in a similar manner. Either design is a superior replacement to plain friction levers.