The Park Tool 789 55.95mm Reamer, click to enlarge

Item # 789

/ Tools / Frame & Fork

55.95mm Reamer

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.

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789 Features

SHIS terminology: The 789 is used for upper and lower head tubes accepting the ZS56 or EC56 headsets.

Compatible Products


Head Tube Reaming and Facing Set


Head Tube Reaming and Facing Set


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