The new M-8 mainsail for the Viper 640 features the very same design and shape of the world winning M-7 mainsail. Because North Sails is always improving and seeking for better products, our sail designers made a recommendation for a cloth switch to Xi-18 which will hold the sail shape longer, with a substantial durability improvement for an overall better...
The M-7 mainsail was designed to compliment a simple tuning system that will help keep you up to speed in a variety of conditions. Chocking the mast in light air induces the proper amount of headstay sag; blocking the mast back and tensioning the lowers straightens the headstay for windier conditions, especially when vang sheeting. By optimizing the full length batten locations, we were able to maximize the sail's...
The new J-5 jib for the Viper 640 features the same proven winning shape as the J-4 jib. The new J-5 is made out of North Sails exclusive reinforced Xi14 Aramid laminate produced using the world’s most advanced sailcloth laminator and North's unique eXact™ process. The result is a high performance cloth with ultimate durability. Learn more about North NPL...
Our redesigned Viper 640 jib has a lower clew so that the lead adjustment is more effective. We also added a full-length top batten, which gives you more control with the jib sheet and the ability to trim harder. The entry is fuller and leech flatter. And a max-length tapered bottom batten, plus additional panels in the head, increase durability.
The North Viper 640 spinnaker reflects the knowledge we've gained by designing winning sails for a variety of sport boats. Our sail is sized to be class maximum and twists and rotates well, so you can sail lower angles while going the same speed or faster.