Mavic Zap (zms 800 2nd style) Electronic Rear Derailleur 8 speed, 1993

Description

The 'Zap MAVIC System 800' (MAVIC Zap ZMS 800) derailleur was the first commercial electronic derailleur.
It works by using the rider's power, driving the guide pulley wheel, to, in turn, drive the gear change. Unlike Shimano's Di2 designs, electric motors were not used for the primary power. But electronics were used to direct the rider's power by extending or retracting small teeth that engaged in helical grooves.
It is part of a wired system that uses very high quality, and ultra-modern, materials. The pulley cage plates are Kevlar composite and the all-important guide pulley and many of the small bolts are titanium. The tension pulley had a beautifully smooth sealed bearing. It weighs 241g.
It has a number of '7880' etched in the silver portion of the derailleur.
Some of its attributes are:
The plastic parts of the body are light grey.
It is branded with a very professional logo with an outline font with silver infill.
The inner pulley cage plate has 'Made in France - US patent pending' writing moulded on it.
Derailleur brand: MAVID
Made in France
Date of introduction: 1993
Date of this example: unknown
Model no.: ZMS 800
Weight: 241g
Maximum cog: 28 teeth (based on MAVIC's figures for the Mektronic)
Total capacity: 30 teeth (based on MAVIC's figures for the Mektronic)
Pulley centre to centre: 48mm
Index compatibility: 8 speed (although you can set it for 7 speed)
Chain width: 3/32”
Logic: not relevant
B pivot: unsprung
P pivot: sprung
Materials: aluminium, Delrin, Kevlar composites, titanium and probably many stainless steel internal parts