SunTour Le Tech (5900)

I think that the SunTour Le Tech was SunTour’s second foray into the world of three pivot derailleurs (the Trimec (6400?) being the first) - and the Le Tech is a blinder - I particularly like the oh-so-modern ‘computer’ type face.

I remember the Le Tech being presented as a pure touring gear - SunTour’s response to the 1981 Shimano Deore. It was Cyclone quality and combined SunTour’s slant parallelogram with the joys of a three pivot design. It gave a very small and consistent chain gap and a lightening quick and pin-point accurate gear change.

With the gift of hindsight, its most surprising feature is that it had a conventional guide pulley that you could remove and replace. I never knew why SunTour ditched this design and adopted the fatally flawed Trimec configuration for the first MounTech models.

However 1982 was not the time to launch a radical touring derailleur - the tidal wave of mountain bike hysteria was just crashing onto the shores of the bicycle world and the Le Tech got washed away in the turbulence.

A forgotten work of (fragile) genius.


  1. Brand: SunTour

  2. My category: SunTour - Frank Berto and the curse of Duopar

  3. Country: Japan

  4. Date of introduction: 1982?

  5. Date of this example: 1983 (two letter date code is ZL)

  6. Model no: 5900

  7. Weight: 308g

  8. Maximum cog: 34 teeth?

  9. Total capacity: 40 teeth?

  10. Pulley centre to centre: 80mm

  11. Index compatibility: friction

  12. Chain width: 3/32”

  13. Logic: top normal

  14. Pivots: three pivots, rear unsprung and the other two sprung

  15. Material: largely aluminium with steel pulley cage plates, link element plate and inner parallelogram plate