Hi from upstate NY

[SpyderV]

I see in the original Sears ad for the Spyder bikes, they offered a 5 speed with optional automatic power shift. How did that shifter actually work, and do any survive today?

 

[deorman]

My guess is that it has a spring loaded cable overload device in the cable or shifter similar to Schwinn Stingray and Fastback models. It allows the shifter to be moved to the next position without directly pulling the derailleur, preventing crunchy shifts and system damage. Member CRASH probably knows if anyone does.