North Sails

  • NORTH SAILS' J/109 TUNING GUIDE

    Base Settings for 10-15 knots True Wind Speed

    Headstay Mast Butt Max J Pre Bend Upper Shroud V1 Lower Shroud D1 Intermediate Shroud D2
    2260mm 460mm 4050mm 20mm 52 Units 27 Units 15 Units

    »     Shroud tensions measured on RT-10 Loos gauge
    » Download North's Quick Tune Card (pdf file, updated March 2010)

    © North SailsHeadstay is measured using swing arc method. Use jib halyard pulled down to top of black band on mast - swing forward to mark headstay. Measure distance from mark on headstay to deck at stem.
    © North SailsThe mast butt is measured from forward face of mast to aft edge of bulkhead. This corresponds to forward most position in the slider.
    © North SailsPre-Bend is measured at point of maximum deflection between S1 and S2 (left).
     
    © North SailsJ Dimension is measured from intersection of stem at shear to forward face of mast (left.)

    Shroud Adjustments Matrix
    True Wind Speed Upper Shroud V1 Lower Shroud D1 Intermediate Shroud D2
    0-5 knots -3.5 turns -3 turns -2 turns
    6-10 knots -3 turns -2 turns -1 turn
    10-14 knots Base 52 Base 27 Base 15
    15-18 knots +2 turns +1.5 turns +1.5 turns
     19-21 knots  +3 turns  +2 turns  +2 turns