Tempest Tuning Guide

Rig Tension

Tight, measured on Jib luff wire 250 lbs.

Mast Rake

Medium winds:- 150-250mm

Strong winds:- 300+mm

Measured using halyard as plumb line, measured at lower black line.

Jib Sheeting

With the jib pulled in tight, the continuation of the jibsheet from the fairlead to the clew should divde the front of the jib 55% up the luff wire. When over powered in heavy winds move the fairlead aft to flatten the jib and open the slot between the jib and the mainsail.

Spreaders

Inital setting should deflect the shrouds out by about 40mm and deflect forward by about 25mm. When they are setup you can convert as below:

Length measured from the shroud to the side of the mast. Check sweep back of spreaders by placing a straight batten from the port spreader tip to the starboard one. Measure from the centre of the batten to the rear of the mast.

LENGTH 260mm (length will vary with different boat designs)

SWEEP BACK 100-150mm (variable)

To make the mainsail fuller swing the spreaders forward. To flatten the mainsail swing the spreaders aft.

Prebend

Check with jib only hoisted and the rig tension on.

Measure to a straight line between masthead and the black band at the gooseneck 25-30mm.

Deck Level Control

With the boat rigged as for pre-bend check, lock the mast at this position. Allow the mast to go forwards 5-10mm in very windy conditions.

Class website http://www.uktempest.co.uk