CMP Synchro derailleur

Ah, the 1930s! When derailleur designers adopted a completely new mechanism every other day of the week. The CMP Synchro uses a double cable to rotate a wheel that uses a rack and pinion layout to drive the pulley cage in and out.

It probably worked OK, if you like that kind of thing.

Derailleur brands: CMP
Country: France
Date of introduction: 1938?
Date of this example: unknown
Model no.: unknown
Weight: 264g including 'U' bracket which may not be original, and excluding pulley cage spring
Maximum cog: unknown
Total capacity: unknown
Pulley centre to centre: 67mm
Index compatibility: friction
Chain width: 1/8”?
Logic: no 'normal' state
B pivot: none
P pivot: sprung
Materials: mainly steel with some rather fetching brass small parts