The Shimano Y3GK89600 is the GG (guide wheel gap) adjustment gauge for the 12-speed Dura-Ace Di2 RD-R9250 and Ultegra Di2 RD-R8150 rear derailleurs. It is placed on the rear derailleur cage to set the correct distance between the guide pulley and the largest cassette sprocket by aligning the sprocket tip with the marked line on the gauge, then adjusting the B-tension screw accordingly.

Fits

  • Shimano Dura-Ace Di2 RD-R9250 (12-speed)
  • Shimano Ultegra Di2 RD-R8150 (12-speed)

Note: This gauge is not compatible with the 105 Di2 RD-R7150 or 12-speed GRX RD-RX825, which require a different gauge (Y3JS9803T) due to different optimal distance settings.

Shimano spare parts are covered by Shimano's standard warranty against manufacturing defects. Please return the item to Tune Cycles for warranty support.
  • Sets correct guide pulley gap (B-gap) on RD-R9250 and RD-R8150 rear derailleurs
  • Place gauge on derailleur cage and align largest sprocket tip with marked line
  • Fits: RD-R9250 (Dura-Ace Di2), RD-R8150 (Ultegra Di2)
  • Not interchangeable with RD-R7150 / RD-RX825 gauge (Y3JS9803T)
SpecificationDetail
Part numberY3GK89600
TypeGuide wheel (B-gap) adjustment gauge
Compatible derailleursRD-R9250 (Dura-Ace Di2 12-speed), RD-R8150 (Ultegra Di2 12-speed)
Incompatible derailleursRD-R7150, RD-RX825 (use Y3JS9803T)
Quantity1 piece
SKU SHM-Y3GK89600
Barcode # 4550170229368
Brand Shimano