Robert Stroj Interview (NeilPryde Design) care of the NP Website.
RS:RACING EVOIII and the Integrated Compact Clew
Q. Some of the top NeilPryde Team Riders will be racing on the EVOIII this season. Why?
As with any very new development it’s always a challenge to get all the little details 100% right and it took a longer time to finalize the design than was originally planned. We wanted to make sure that there was plenty of testing before the sail gets introduced to the market.
For those reasons we decided to have only our international team register and use the new RS:RACING EVOIII sails during the 2010 racing season so that we can introduce fully tested sails to the market later this year.
Q. Will there be a difference in the EVOIII sails introduced to the market later in the year from the ones the Team Riders are using now?
The sails introduced to the market will be the same designs as used by the team during the season, but will be introduced in new colors and different graphics.
This is a very similar concept to the current EVOII Limited Edition sails which are exactly the same designs as the regular 2009 EVOII sails, just with new graphics and colors.
Q. What is new with this sail design?
With this sail we introduce the Integrated Compact Clew where, in comparison to the current Dynamic Compact Clew, we have eliminated the cutout at the clew and connected the foot area with the leech by closing the sail behind the boom end.
I have been thinking about this clew concept since my time at ART. After the introduction of the Compact Clew that came out on the RS5 at the end of 2004 I was hoping to be able to take this concept one step further and use all the advantages of the Compact Clew without having to compromise the outline of the sail.
Q. How does it work and what are the advantages?
The real advantage of this concept is that there is a tension connection between the foot edge and lower leech. This helps to keep the foot of the sail from blowing out in gusts and also makes the whole leech twist, harmonically, getting even more out of the advantages already associated with the regular Compact Clew.
In addition, there is the benefit of a cleaner sail outline, when compared to the Dynamic Compact Clew, and therefore better aerodynamics as it is not necessary to have a clew cutout.
In comparison to regular sails with a clew on the back edge of the profile the EVOIII has all the benefits common with the Dynamic Compact Clew: improved lower leech twist and much reduced draft movement due to the lower leech ability to create reflex behind the boom which releases excessive power and effectively locks the draft forward.
After long development (since May 2009) we ended up designing a very simple and precise sliding rail system for sail closure behind the boom. It works similar to a zip but is much stronger and incorporates a batten to support this area as well as evenly distributing the high load coming from the clew grommet.
With this system being very new we decided, like previously mentioned, to ensure it is fully tested prior to introducing new sails to the market.