DISRAELI GEARS

microSHIFT Arsis (R66S)

microSHIFT Arsis derailleur (R66S) main image

The microSHIFT Arsis is another of the new ‘aspirational’ generation of Taiwanese derailleurs - an attempt to do for Taiwan what the Shimano Crane did for Japan three decades earlier. As with most ‘aspirational’ Taiwanese gears, the Arsis is manufactured for microSHIFT by SunRace.

It ticks a lot of the right boxes - carbon wrapped outer parallelogram plate, CNC machined outer pulley cage plate, CNC pulley wheels with sealed bearings, titanium small parts, aluminium hanger bolt and 10 speed compatibility.

And just like the Crane all those years ago, there is a certain immature teenage feel to it - the branding is slightly crass, there is too much writing everywhere (the Arsis doth protest too much, methinks), the finish is slightly inconsistent (beautifully polished here, slightly rough and ready there), on this example the titanium tension pulley bolt is about a millimetre too long and, as always with SunRace, 196g is not especially light given all that technology (what is ‘carbon wrapping’ all about anyway?).

An excellent try.


  • Derailleur brands: microSHIFT, manufactured by SunRace
  • Country: Taiwan
  • Date of introduction: 2007?
  • Date of this example: 2007?
  • Model no.: R66S
  • Weight: 196g
  • Maximum cog: 27 teeth (source: microSHIFT)
  • Total capacity: 29 teeth (source: microSHIFT)
  • Pulley centre to centre: 49mm
  • Index compatibility: 10 speed
  • Chain width: 3/32”
  • Logic: top normal
  • B pivot: two sprung pivots
  • Materials: Aluminium (including the hanger bolt), with ‘carbon-wrapped’ outer parallelogram plate and titanium cable clamp, cable outer adjuster and adjustment screws.
microSHIFT Arsis derailleur (R66S) additional image 01
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