DISRAELI GEARS

Supjam Mundial (M-U-57)

Supjam Mundial 57 main image

The Supjam Mundial is an interesting derailleur. It is extremely derivative of the Simplex Tour de France - with one absolutely crucial difference - the pulley cage pivot is between the pulleys and offset from their centre line. The Simplex Tour de France has the pulley cage pivot concentric with the guide pulley. It is not impossible that Supjam's modification gives a greatly improved change - but it is still odd, because Lucien Juy, the owner and chief designer, at Simplex was adamant that his way was the only correct one. Why did Supjam copy something so faithfully - if they were then going to commit an unpardonable heresy?

The b-pivot bolt is labelled 'M-U-57', very much in the way that Simplex labelled the 1951 Simplex Juy-51 with 'Simplex JUY 51' on this bolt. You might guess from this that the Supjam Mondial dates from 1957.


This example of a Mundial has steel parts with a slightly dull (shall we say 'silk'?) plated finish. It also has a golden, aluminium, outer pulley cage plate and one pulley bolt labelled '3 Velocidades' - so it is a 3 speed.


  • Derailleur brands: Supjam
  • Country: Argentina
  • Date of introduction: 1957?
  • Date of this example: unknown
  • Model no.: unknown
  • Weight: 291g including the hanger plate
  • Maximum cog: 24 teeth (guess)
  • Total capacity: 24 teeth (guess)
  • Pulley centre to centre: 46mm
  • Index compatibility: friction
  • Chain width: 1/8"?
  • Logic: low normal
  • B pivot: sprung
  • P pivot: sprung
  • Materials: steel with an aluminium outer pulley cage plate
Supjam Mundial 57 additional image 01
Supjam Mundial 57 additional image 02
Supjam Mundial 57 additional image 03
Supjam Mundial 57 additional image 04
Supjam Mundial 57 additional image 05
Supjam Mundial 57 additional image 06
Supjam Mundial 57 additional image 07
Supjam Mundial 57 additional image 08
Supjam Mundial 57 additional image 09
Supjam Mundial 57 additional image 10
Supjam Mundial 57 additional image 11
Supjam Mundial 57 additional image 12
Supjam Mundial 57 additional image 13
Supjam Mundial 57 additional image 14
Supjam Mundial 57 additional image 15
Supjam Mundial 57 additional image 16