J/109 Tune Settings
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)
Headstay 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.
 
The mast butt is measured from forward face of mast to aft edge of bulkhead. This corresponds to forward most position in the slider.
 

Pre-Bend is measured at point of
maximum deflection between
S1 and S2 (below ).

J Dimension is measured from
intersection of stem at shear
to forward face of mast (below.)

   
   
Shroud Adjustments Matrix
True Wind
Speed

Upper
Shroud
V1

Lower
Shroud
D1

Intermediate
Shroud D2

0 - 5 knots
-2.5 turns
-2 turns
-2 turns

6 - 10 knots

-2.5 Turns
-1 Turns
-1 Turns
11 - 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

 

Jack Orr is the J/109 Class Leader for North Sails' Class Development Program (CDP). He has all the info to help you go faster and have more fun on your J/109. Browse through the CDP site and feel free to contact Jack with any questions from tuning to class rules and everything in between. He can also help you find the J/109 expert nearest you, so contact Jack today!