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.

It ticks a lot of the right boxes - carbon wrapped outer parallelogram plate, CNC machined outer pulley cage plate, pulley wheels with sealed bearings, titanium small parts, aluminium hanger bolt and 10 (or later 11) 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) and it is not especially light given all that technology (what is ‘carbon wrapping’ all about anyway?).

But it was an excellent try.

I am aware of at least three generations of microSHIFT Arsis:

  • First up is the microSHIFT Arsis (R66). This was for 10-speeds, had CNC drilled pulley wheels and a rather bling, CNC, drilled, 50mm pulley cage.
  • The second iteration is the microSHIFT Arsis (R67). This is a total redesign, with a horseshoe shaped cutout in the outer parallelogram plate, the pulley cage gets lengthened to 56mm and the CNC pulley wheels get replaced with plastic items (albeit also with sealed bearings).
  • And finally there is the microSHIFT Arsis11 (R68). Another total redesign. The p-knuckle becomes a more modern but less distinctive shape. The bling content also, and very regretably, gets dramatically reduced.


This is an example of the first generation microSHIFT Arsis (R66). Some of its features are:

  • It's a 10-speed device.
  • The outer parallelogram plate is a conventional shape.
  • It has a very year-2000-Campagnolo, polished aluminium, Zeppellin shaped p-knuckle.
  • The pulley cage is 50mm long.
  • The adjustment screws are titanium with Phillips heads.
  • The machined aluminium pulley wheels have sealed bearings.
  • The cable clamp washer has one tab.


  • Derailleur brands: microSHIFT
  • Country: Taiwan
  • Date of introduction: 2008
  • Date of this example: unknown
  • Model no.: R66S
  • Weight: 196g
  • Maximum cog: 27 teeth (source: microSHIFT)
  • Total capacity: 29 teeth (source: microSHIFT)
  • Pulley centre to centre: 50mm
  • Index compatibility: 10 speed Shimano
  • Chain width: 3/32”
  • Logic: top normal
  • B pivot: sprung
  • P pivot: sprung
  • Materials: Aluminium (including the hanger bolt), with ‘carbon-wrapped’ outer parallelogram plate and titanium cable clamp, cable outer adjuster and adjustment screws.

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Browse associated documents.



microSHIFT instructions - Rear Derailleur - Road

microSHIFT instructions - Rear Derailleur - Road

microSHIFT instructions scan 1 thumbnail


microSHIFT 2008-2009

microSHIFT 2008-2009

microSHIFT 2008-2009 front cover thumbnail



microSHIFT 2009-2010

microSHIFT 2009-2010

microSHIFT catalogue - 2009-2010 scan 1 thumbnail