Shimano had launched their Positron indexed system in 1975, and it soon became clear that indexing was not going to go away - so SunTour had to respond. The SunTour Mighty Click (wacky name!) was their first response. Unlike Shimano’s low-end effort, the Mighty Click was a mid-range design, with a slant parallelogram and an aluminium rear knuckle.

In many ways the Mighty Click is much closer to the era-defining Shimano SIS than it is to the contemporary Shimano Positron:

• Positron does not have a slant parallelogram and has the indexing mechanism in the derailleur (in both cases like the SunTour manufactured Bridgestone Synchro Memory Shift).
• Mighty Click and Shimano SIS both have slant parallelograms and both have the indexing in the lever.

The Mighty Click also has a sprung cable saver, which many of the earlier lower-end Shimano SIS derailleurs also had.

So how is it the Shimano SIS changed the world but the Mighty Click disappeared without trace? I think a lot of the explanation comes down to two things:

• Shimano was willing to put in between ten and a hundred times as much effort in terms of money, engineering hours, management attention etc..
• Shimano controlled, and was willing to optimise, every part of the transmission, from the derailleur, to the lever, to the sprocket teeth, to the chain, to the cable inner wire, to the cable outer casing and on and on. SunTour could never do this, and possibly never wanted to.

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I believe that this is a later example of a, mid-length cage, SunTour Mighty Click (2700). Some of its features are:

• The SunTour logo on the outer parallelogram plate is the newer, bolder, version without a 'split T'.
• It has a pulley cage with a Quick Cage. In this case it is 59mm long.
• The sprung cable saver is different from that in early versions, with the internal cylinder completely enclosed in the outer cylinder.
• The hanger plate has a reverse slot, as is common in Japan.
• The adjustment screws do not have knurled heads.

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• Derailleur brands: SunTour
• Categories: SunTour - indexing insanity
• Country: Japan
• Date of introduction: 1980
• Date of this example: 1982 (two letter date code is YF)
• Model no.: 2700
• Weight: 377g including hanger plate
• Maximum cog: 30 teeth (Source: SunTour)
• Total capacity: 22 teeth or 30 teeth (Source: SunTour - which is a touch confusing)
• Pulley centre to centre: 58mm
• Index compatibility: 5 speed
• Chain width: 3/32”
• Logic: top normal
• B pivot: unsprung
• P pivot: sprung
• Materials: mainly steel with an aluminium rear knuckle

Ref. 326