> Does anyone on this newsgroup have experience with the Delta mast
> available from Multisail? It's a 460 or 500 cm mast (carbon fiber content
> of 60 or 100%) of which the bottom 40 cm can be removed. It is made by
> Powerex. While the Delta mast was designed to make changing sizes of the
> Multisail easy, I notice that Windwing is offering fixed length 40 and 60
> cm mast base extensions in their 1998 catalog, and suspect this is
> basically the same idea. I believe Windwing masts are made by Powerex now.
FYI: The use of the fixed 40cm carbon base extension will convert a
460/25 (MCS and IMCS) 12% constant curve to a (measured) 490/22 MCS 11%
constant curve (IMCS 25). I measured this set-up as a 490 for comparison
with our 490/26 (IMCS 29.5) made by Powerex as an alternative to buying
a 490 for our larger sails. The overall stiffness is less, IMCS 25 vs.
29.5, and the mast is 1% softer at the booms. For lightweight sailors in
sails with ample luff curve and multiple stiff race-type battens, i.e.
our Synthesis and Race CS models, this arrangement will work reasonably
well adding pumpability and attendant low-end power with a slight loss
in overpowered stability. It isn't recommended for aggressive
heavyweights. Our 9.0 Race CS is designed for use of a fixed carbon base
extension (or other suitable extra long base) and a 490/26 mast.