SunTour AG Tech (5000)

SunTour AG Tech derailleur (5000) main image

In 1981 SunTour introduced a 14 to 38 toothed five speed freewheel and called it the AG for ‘Alpine Gear’. It was designed to allow you to get stump-pullingly low gears on a ten speed set up. I think 38 teeth remains, to this day, the largest rear cog to be commercially available. To handle this monster SunTour produced a succession of ‘AG’ derailleurs, which were huge, crude, rock crushers loosely derivative of the SunTour seven - with a scaled up, aluminium, rear knuckle from the V series, and a scaled up, steel, front knuckle from the Honor. The whole AG system was vaguely clunky - too big, too heavy, too ugly and with too large a difference between the ratios, but it had a devoted band of followers who wanted that ultimate low gear experience.

This example is the AG Tech, with SunTour’s mid length, first generation, double pivot ‘Tech’ pulley cage grafted onto the AG parallelogram.

Sometimes it’s better to get off and walk.

  • Derailleur brands: SunTour
  • Categories: SunTour - Frank Berto and the curse of Duopar, SunTour - weirdness
  • Country: Japan
  • Date of introduction: 1983
  • Date of this example: 1983 (two letter date code is ZC)
  • Model no.: 5000
  • Weight: 358g
  • Maximum cog: 38 teeth (Source: Sutherlands 4th edition)
  • Total capacity: 34 teeth (Source: Sutherlands 4th edition)
  • Pulley centre to centre: 65mm
  • Index compatibility: friction
  • Chain width: 3/32”
  • Logic: top normal
  • B pivot: unsprung
  • P pivot: sprung
  • Materials: largely steel with an aluminium rear knuckle
SunTour AG Tech derailleur (5000) additional image 01

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