With the XC Pro groupset SunTour tried to take the fight to Shimano by claiming the high ground above Deore XT. This derailleur is very well made, with a high gloss finish, sealed bearing pulley wheels and a solid business-like feel. As was de rigeur at the time, it has two sprung pivots and a slant parallelogram. It was an impressive piece of equipment, but Shimano had better chains, better sprockets, better marketing and a better reputation.

This is the longest cage version of the three.


  1. Brand: SunTour

  2. My category: SunTour - the mountain bike gears

  3. Country: Japan

  4. Date of introduction: 1990? (instructions printed in 1990)

  5. Date of this example: 1991 (two letter date code is HJ)

  6. Model no: XP00-GXB

  7. Weight: 278g

  8. Maximum cog: 28 teeth (hanger 24mm), 30 teeth (hanger 26mm) or 32 teeth (hanger 28mm or more) (Source: Sutherland’s 6th edition)

  9. Total capacity: 40 teeth (Sutherland’s 6th edition)

  10. Pulley centre to centre: 85mm

  11. Index compatibility: 7 speed?

  12. Chain width: 3/32”

  13. Logic: top normal

  14. Pivots: two sprung pivots

  15. Material: largely aluminium with a steel inner pulley cage plate


SunTour XC Pro GX  (XP00-GXB)