Carbon content versus bendcurve

I have now multiple sails (different brands). In the past I always chose the recommended mast, but since 2017 I tried random masts (which we already had). Read the experiences of this year:

I have a loft sails blade with RDM mast, perfect sail well made. And than I got the mast, the mast was made 3~4 years later (a newer mast). Turned out the first sessions that this mast did make the sail a bit stiff (yes a RDM...). But after I  used the mast in the same position (labels up) after 3 times it became better. I still use this sail, even did my best hour since a long time with this 2010 sail. Mast is 100%, however not perfect, but OK now. I think I will use this sail till it breaks in pieces. I feel very confident that this sail and mast won't let me down, the sail might tear at one point but if will take me back. This is my sail for crossings etc.

There are 2 prydes in the car (RS Slalom MK3), and X6 masts. Sails and masts match (same production year). A proof that recommended mast is good. (My brothers equipment)

I have a point 7 (in picture), I bought a 100% point7 mast (like recommended). However this mast was 7 years older than the sail. You might guess, the bendcurve is off. The sail is sailable, however its not sweet. Later I bought a 430 point 7 (same year), however this mast (base+top) broke in transport. At that moment I thought why not put the Neilpryde X6 mast in the point 7, and this 60% different bendcurve mast is my choice eversince. At first I was a bit affraid I would break the X6 (since I broke a X6 in a severne reflex). But the X6 mast is still in one piece after 10? sessions. X6 gives more control, there is a sweetspot and I like it. Even did my 2017 personal best on this mast.

-Recommended mast can be totally wrong if the years (sail and mast) don't match;
-A wrong bendcurve is probably worse than low carbon content;

-How long will a 60% (or low carbon content) mast last in a fullrace sail, I am affraid that glassfibers wear (break) quicker compared to 100% carbon? Is this true or not? I will order a 100% mast soon, because I don't like to swim with windsurf gear.

Erik Loots

Erik is windsurfer for 10+ years. In his daily life he is professional in construction dewatering, advisor, troubleshooter. Erik likes adventures, explore and to challenge himself. During his life he is trying to get the best out of it and have respect for the earth, nature and future generations. The modern world is about sharing, in this blog Erik shares his experiences, selfreflection and lessons learned.


  1. Great post on the virtues of mast compatibility.

    Years ago, the accepted wisdom was that higher carbon meant more fragile.

    Unifiber tends to confirm that:

    "Lower carbon content gives two main advantages. Cheaper masts and actually stronger masts in many cases too."

  2. Carbon fibers often breaks instantly. I believe that a unbroken 100% carbon mast is as good as new, even after 1000 sessions. While glas and especially kevlar are more behaving like slowly degrading (like a cotton cloth slowly tearing). I believe lower carbon content masts do not break as quick, but I doubt that these mast have equal properties after many sessions.