SunTour Superbe Tech GTL (5400)

SunTour Superbe Tech GTL derailleur (5400) main image

The story of the SunTour Superbe Tech series is a perfect example of hubris - of overweening pride, self-confidence, and even arrogance resulting in fatal retribution (you can’t beat Wikipedia for a definition).

In 1982 SunTour was at the peak of its powers, dominating the world market for derailleurs like a colossus. The French were vanquished, the Italians driven back into their tiny road racing redoubt and Shimano was smarting from the market failure of its Positron and Dura-Ace AX initiatives.

SunTour decided that it would redefine the derailleur for a generation - and that the Superbe Tech would be that redefinition. The cable run was under the bottom bracket, along under the chainstay, then through a clamp-on tubular guide and straight onto the clamp bolt. No cable outer anywhere to get clogged with mud. The parallelogram was completely enclosed, with the smooth enclosure effectively acting as one parallelogram plate. The longer cage versions had SunTour’s ‘Tech’ cage design. Combine it all with SunTour’s slant parallelogram and reputation for reliability and you have a brilliant package, so far ahead of anything anyone else had to offer that it was over the horizon. I remember the Superbe Techs as being irresistable to bike freaks everywhere, we all wanted to admire them, touch them and even, despite the expense, to dream of buying them.

But the Superbe Tech was a flawed work of genius, it shared with the MounTech the problem of the unreliable, irreplaceable guide pulley, it shared with the MounTech the problem of the excessive weight of all this technology, and it went beyond the MounTech in that the fancy sealed parallelogram went out of alignment and was hell to disassemble and repair.

This long pulley cage ‘GTL’ example perfectly illustrates this last problem. Whilst the parallelogram enclosure was effectively one ‘paralellogram plate’, the role of the other ‘parallelogram plate’ was played by a piece of spring steel wire, only about 1mm in diameter and anchored by right angle bends at either end (US patent # 4,469,479 figure 4a shows an exploded diagram). In use these right angle bends straightened or even broke and the parallelogram was no longer parallel. In the photo above you cannot see through the the hollow hanger bolt because it is so badly out of alignment with the pulley cage. Contrast this with the photo of my SunTour Superbe Tech L, which has yet to suffer from this problem. It’s a weird mistake to make, if SunTour had only used 2mm square section spring steel we might all be riding around with enclosed parallelogram derailleurs to this day.

  • Derailleur brands: SunTour
  • Categories: SunTour - the Superbe story, SunTour - the mountain bike gears, SunTour - Frank Berto and the curse of Duopar
  • Country: Japan
  • Date of introduction: 1983
  • Date of this example: unknown (it’s all too beautiful to mar with a two letter date code)
  • Model no.: 5400
  • Weight: 306g
  • Maximum cog: 34 teeth (Source: Sutherlands fourth edition)
  • Total capacity: 40 teeth (Source: Sutherlands fourth edition)
  • Pulley centre to centre: 85mm
  • Index compatibility: friction
  • Chain width: 3/32”
  • Logic: top normal
  • B pivot: unsprung
  • P pivot: two, both sprung
  • Materials: largely aluminium with steel pulley cage plates and link element plate

Browse associated documents.

US Patent # 4,469,479 - SunTour

US Patent # 4,469,479 - SunTour

US Patent 4,469,479 - SunTour Superbe Tech thumbnail

Japanese Patent # S59-102681 - Shimano

Japanese Patent # S59-102681 - Shimano

Japanese Patent S59-102681 thumbnail