You would naturally expect an inexpensive derailleur produced in Mexico in 1981 to be a copy of either a Shimano Skylark or a SunTour Honor. But this Mendoza model is possibly more of an, admittedly steel, copy of a 1970s Simplex Prestige. It has got two sprung pivots, like both a Simplex and a Shimano (but not a SunTour). But:

• its pulley cage is 46mm long,
• there are Allen bolts at the b-pivot and p-pivot,
• the adjustment screws are on the front side of the outer parallelogram plate,
• the pulley cage plates are concave pressed steel,
• the gear hanger plate has a distinctive shape,

all of which echo Simplex more than Shimano.

The outer parallelogram plate carries a rather fine image of one of the Mendoza company's signature products - the 1940s Mendoza RM2 light machine gun. Despite the close relationship between the firearms industry and the bicycle industry, I can only think of one other derailleur that was decorated with an image of a firearm - the BSA 4-Star.

This is one of two Mendoza derailleurs on this site, the other is here. They are very similar but have detail differences, for example in the pulley cage stop.

• Derailleur brands: Mendoza
• Country: Mexico
• Date of introduction: 1981?
• Date of this example: unknown
• Model no.: unknown
• Weight: 326g including hanger plate but without small hanger bolt
• Maximum cog: 28 teeth? (Simplex claim 30 teeth for a 46mm cage but I never quite believed it...)
• Total capacity: 28 teeth? (Simplex claim 30 teeth for a 46mm cage but I never quite believed it...)
• Pulley centre to centre: 46mm
• Index compatibility: friction
• Chain width: 3/32
• Logic: top normal
• B pivot: sprung
• P pivot: sprung
• Materials: steel