Item # 789
Reams head tube I.D. to 55.95mm to accept “internal” headset cups with 56.00 - 56.10mm O.D. (1-1/2 ZS standard). Used with #690-XXL Facing Cutter and #750 Centering Cone Adaptor. Designed for use with the HTR-1 or HTR-1b Headtube Reamer and Facer.
NOTE: For sharpening services of cutting tools see Park Tool Sharpening Services. Always use cutting fluid such as Park Tool CF-2 when machining.
SHIS terminology: The 789 is used for upper and lower head tubes accepting the ZS56 or EC56 headsets.