This gear caused me distress and dismay when it appeared. SunTour seemed to have abandoned the best design in the world (the slant parallelogram) and copied the geometry of the much despised 1976 Huret Eco, which was, in turn, the bastard child of the 1963 Huret Svelto.

The design did have some interesting details. SunTour had adopted a ‘Light Action’ style sprung cable clamp (in imitation of one of Shimano’s better features). The top pulley was dramatically off-set from the lower pivot, in an attempt to get the Huret geometry to provide a decent change over a wide freewheel.

Despite these touches SunTour’s decision to adopt this geometry was like Ferrari deciding to copy a Lada.

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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: 1982 (two letter date code is YG)
   

6. •Model no: 4600?
   

7. •Weight: 308g including hanger plate
   

8. •Maximum cog: 28 teeth (Sutherland’s 6th edition)
   

9. •Total capacity: 28 teeth (Sutherland’s 6th edition)
   

10. •Pulley centre to centre: 60mm
    

11. •Index compatibility: friction
    

12. •Chain width: 3/32”
    

13. •Logic: top normal
    

14. •Pivots: two pivots, front sprung and rear unsprung
    

15. •Material: largely steel, aluminium top knuckle
    

0258/I