in Masts

We often believe that the carbon content percentage from the mast is the main important thing. The truth is that it’s better to have the correct curve, rather than any random 100% carbon mast with the wrong curve.

The mast is not only about the Imcs, which is the central stiffness, but also mainly about the curve percentage of the base and of the top. These curves are what classify a mast to be flex top of constant curve. The percentages do not give only these two options.

There are many combinations, which different brands can use, to fit their development needs through the mast. For example, a flex top mast can be more flex top than another mast.

Mast base curve (lower area) IMCS (central area) Mast top curve (higher area)
Range 61 – 64 14 – 38 73,5 – 78
Costant Curve POINT-7 curve Costant Curve POINT-7 curve Costant Curve POINT-7 curve
430 63 63,5 21 22 75 75
460 63 62,5 25 25,5 75 75,5
490 63 61,5 28 -29 27,5 75 76



The lower the percentage value, the stiffer the base. The higher the percentage value, the softer the base.


The lower the value of IMCS, the softer the feel of the mast. The higher the IMCS value, the stiffer the feel of the mast.


The lower the percentage value, the stiffer the top. The higher the percentage value, the softer the top.

Results on the water


A softer base creates less profile in the lower part of the sail, but donates more comfort against rough waters. A stiffer the base of the mast, obtains more drive and power.


The IMCS works as a transition value from the base to the top of the mast. It’s a value that allows the sail to feel stiffer or softer. A good compromise to make the sail feel comfortable according to its size, it is giving a good feedback.


A softer top to allow the sails to breath, and gives the extra edge while pumping in light wind. A stiffer top of the mast, would allow more stability in rough conditions.

Our mast curve characteristics


Our shorter masts are softer base, so higher curve percentage value from standard, to allow more comfort. While our longer masts have stiffer bases, so a lower percentage value to allow more power and drive.


If we have a stiff base, we often try to go slightly softer in the IMCS than the standards normally offered. This gives a good synergy between the base and central part of the mast to express the best performance and comfort. The same is done on soft bases, we make sure that the IMCS is slightly stiffer to compensate the softer base.


In our case, our shorter masts are having a stiffer top, so a lower percentage curve value to allow more stability. Our longer mast have often softer tops, so a higher percentage value to allow more breathing and light feel on the higher part of the sail.



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