This collaboration began in July 2003 when we designed and built with Laurent Allard the sails for “Leon” ,the JPK 960 of JP Kelbert (Jacques Valer architect ). The boat - skippered by Erwan Dubois - won the Tour du Finistere, without any preliminary sail testing. 2004 was the year of JPK 960 « Guyader l’Esprit de la mer » Indeed, the boat won every leg of the UNCL Atlantic Trophy (except for the Atlantic Télégramme of Lorient, where she was 2nd) and allowed the French Team to take the 2nd place at the Commodore' s Cup, thanks to its victory in the Channel Race. For the 2004 season, with Allard sails, we developed and built an ensemble of running sails to be set from the bowsprit , particularly effective and “covering” this whole sector of apparent winds : 3 asymmetrical spinnakers (light, medium and heavy, all out of Contender nylon) + 1 code 0 (Bainbridge Kevlar™) very effective in the breeze during the Tour de l’ Île de Ré (25-28 knots true, at 100-110° from true wind) but especially in the Channel Race light air, which was the long distance race for the 2004 Commodore' s Cup. The other sails were made out of Graph X GPL by Dimension Polyant, whose behaviour in time - and thus their shape holding capability - were amazing, as the boat used the 2004 mainsail for the 2005-2006 Transquadra. 
2005 confirmed - if needed be - the JPK 960 offshore vocation during the Transquadra : Philippe Debicki (“Supersonic”, Allard sails) made a 2nd place singlehanded, after threatening the 1st place of Philippe Massu (also on JPK 960) until the end. From Brest, Patrick and Anne Farcy (“Cavok”, Yucca sails) took a very nice 3rd place, doublehanded. 
Also doublehanded, JP Kelbert and Herve Perroud (“Leon”, Allard Voiles) after a run of ill-luck in the 1st leg, took their revenge in the second which they won overall on corrected time, finishing 2nd in elapsed time, in front of some 45' footers ! | 2006 : Launching of JPK 11m « Guyader » 
This boat is the result of a common reflexion between architect Jacques Valer and the boatbuilder ; deck plan, mast and sails, by sailors Erwan Dubois (skipper), Illy Brummer (helmsman and sparmaker) and Alain Le Roux (mainsail trimer and sail designer). For the mast (Lorima Carbon) and sail plan, we jointly decided (Erwan, Illy and Alain), on Illy's proposal, to move the shrouds chainplates further inboard by reducing the length and the angulation of the spreaders. Moreover, to allow the use of code 0 (obstruction of the gennaker furler) and asymmetrical spinnakers on spinnaker pole, we moved back the forestay chainplate as well as the mast base by 80 mm, to preserve the J measurement recommended by Jacques Valer. To better circumvent the “code 0 envelope” in relation to the standing rigging, to define the sheeting angles, the angulation and orientation of the sail tracks and to validate the theoretical form, I carried out a 3D modeling of this sail on its rig before realization (just as for the other sails) : The result was a very powerful reaching sail (twice the area of the largest genoa), acting as an “afterburner” in light air, and this, at very close angles to the wind, i.e 32° TW in 8 knots of TW : + 1.5 knots of hull speed). Of course, this sail was well within the IRC spinnaker design rules, with a mid-girth SHW greater than 75% of spinnaker foot SF. We chose, in agreement with Erwan Dubois and Laurent Allard, the D4® technology marketed by Dimension Polyant for the main and foresails : the composition of the selected film on film membrane was 50% carbon and 50% Technora Black. The result answered our expectations, namely, very light sails, a perfect behaviour of the leech profile and an astonishing durability (no sail replaced during the season). The JPK 110 “Guyader” is used by Dimension Polyant for its advertising on D4® technology since August 2006 (photo J. Vapillon). The spinnaker inventory was based on some principles that we had checked during the previous seasons : * light air : for optimal VMG and reaches on coastal course : 0.75 and 0.60 asymmetrical spinnakers on spinnaker pole from 0 to 14 knots TW * medium and medium heavy : 0.75 symmetrical spinnaker to “dive on the leward mark” in up-and-down courses * reaching in strong wind and running in 30 knots and above : 1.50 asymmetrical spinnaker flown from the hounds * reaching in light air (see above) and non spinnaker close reaches : code 0 in AKS 03 1.0 mil on gennaker furler. Spinnaker pole is maximum allowed under IRC, without penalty (thus largely longer than J measurement) Alain Le Roux ©
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