When I started with the BIC Dufour there were long one-piece masts that stayed where they were ie hard to transport. I managed to break one by vaulting over it while hooked into the harness. Mast bases did not have the three (3) pulley systems and were hand hauled. This meant they did NOT bend much.
Two (2) piece epoxy (and later carbon) masts could at least be transported in the car when mobile. Early one-piece mast equipment probably was transported to the lake and stayed there. ( I actually read somewhere that North Sails was now offering three (3) piece masts !! )
I went from fibreglass/epoxy masts to a 490 cm SRS 90 % constant curve carbon mast with an IMCS of 29. It is from an obscure company called Autima out of Taiwan. Lesson number one: buy from the sail manufacturer or at the very least, use a mast approved by your sail maker or someone you trust. My mast works fine, but they do not answer e-mails nor phone calls. I just wanted more information on the specs $%^&*(
So, we went from one and 2 piece masts to carbon masts with many different lengths, now widths (SRS and RDM), carbon content and bend characteristics. Some people say windsurfing is too technical :-) The easy way out is: purchase the recommended mast from the sail maker :-)
Length: Masts seem to vary from about 370 cm to 550 cm in increments of 30 cm. Obviously length is all about fitting into the sail without too much sticking out the top or bottom.
Width: SRS or standard radius/diameter was the norme until recently with RDM, reduced diameter. They say reduced diameter is stronger and less likely to break, especially when doing wave sailing. Wave sailors also seem to use lower carbon content. Once again this is to reduce breakage. RDM masts are actually thicker and heavier. Some swear by them and others do not. Some say heavyweights should stick to SDM and...
In other words , there is NO rule or recommendation written in concrete. Sometimes it is what you like !!!
Carbon content: Seems to go from 30 % to 100%. Read somewhere that 100 % is actually a myth. Lower values seem to break less and do not whip back as quickly - from what i have read. Higher carbon content is supposed to be lighter as well. Bigger sails and race sails seem to prefer higher content- and bigger riders too. Guy Cribb says put out as much money as you can on carbon content. Better recovery and efficiency.
Bend: Little bit of controversy here :-) IMCS or Indexed Mast Check System would logically be the standard, but it is not. Masts of the same length and carbon content may have the same IMCS, but behave completely different in the same sail. Here people speak about flex top (Niel Pryde), constant curve (Sailworks) and hard top (Maui Sails n Gaastra). This is why it is important to put the "correct" mast in your sail. Once again, if you buy the recommended mast from the sail maker, IT SHOULD BE NO ISSUE...
Peterman has written a much-quoted page on the subject of IMCS and mast bend: Peterman IMCS comments and Perterman Mast Article. There was also an article in French Planchemag in 2010 I believe. I thought I had a copy, butt all it informed me was : donut put a NP mast in an MS sail and vice versa :-( Thought there would be more specifications. Then again perhaps I did not have the right edition.Can also check here : mast tool selector - unifiber
0 - 6: Hard top.
7 - 9: Hard top - constant curve.
10 - 12: Constant curve.
13 - 15: Constant curve - flex top.
16 - 18: Flex top.
19 - 21: Flex top - super flex top
22 - : Super flex top.
here is the chart from unifiber:
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| clique to enlarge |
Constant Curve a.k.a. stiff top
Any mast with a base - tip percent of mid-point difference in the 10% - 14% range is considered to be a 'constant curve' mast. The 'classic' definition of a constant curve mast is a mast having a 76% tip deflection percentage and a 64% base deflection percentage. These masts are often labeled as 12% constant curve masts. (as in the example above)
Flex Top
Any mast with a base - tip percent of mid-point difference in the 18% - 22% range is considered to be a 'flex top' mast. The 'classic' definition of a flex top mast is a mast having a 82% tip deflection percentage and a 62% base deflection percentage. These masts are often labeled as 20% flex-top masts.
Combi Curve
Any mast with a base - tip percent of mid-point difference in the 14% - 18% range is considered to be a 'combi curve' mast. The 'classic' definition of a combi curve mast is a mast having a 79% tip deflection percentage and a 63% base deflection percentage. These masts are often labeled as 16% combi curve masts
The above numbers were taken from Peterman and the discussion from somewhere else {i believe}
personally separate hard top from constant curve => some call them stiff top
super hard top - Maui Sails
hard top - Gaastra, older NP masts from the Barry Spanier era, Severne, Naish RDM
constant curve - the majority - Sailworks, Aerotech, Naish,
flex top - newer Niel Pryde, North, Ezzy ?, Hot Sails Maui ?
NOTE: I just added the word newer to Niel Pryde in the flex top section. The reason or this is the following: on the MauiSails forum, there was some discussion about the NP CK66 mast and MS sails. This mast is from the Barry era with NP ie over 10 years ago and DOES work with the MS sails. Life is full of surprises :-)
The following is from the NorthSails website:
Thanks to our new mast measuring and our refined IMCS system, we were able to analyze the masts of all other brands. This allows us to say exactly how good NorthSails masts work with other brand sails or which masts from other manufacturers are compatible with NorthSails:
• NorthSails compatible masts / sails: Aerotech / Ezzy / Goya / Hot Sails / KA Sails Loft Sails / SailWorks / Simmer / XO Sails
• NorthSails partly compatible masts / sails (at about 30-40% performance loss): Gun Sails / Point 7
• NorthSails incompatible masts / sails:
Hard Top: Gaastra / Maui Sails / Naish Sails / Severne
Flextop: Insert Tushingham / Neil Pryde
The importance of the mast is almost always extremely underestimated. In fact the mast is the engine of each rig. Or in other words, a Ferrari chassis with a beetle engine will never become really fast!
what about masts like Powerex, Fiberspar and NoLimitz ?? (and dynafiber, UP, etc) Will do a follow-up on this, but so far my understanding is - these are all constant curve. So far it seems the Fiberspars could be used with the earlier MS TR sails, but NO more. This means they are CC tending towards hard top. So far it seems Powerex are softer top and harder bottom than MauiSails masts - which are at the extreme left. This makes it seem like Powerex are closer to NP/Niel Pryde. The mast bend curve for NL is posted on their site: its about 65 77% or 12 http://www.nolimitz.com/popup_mast_specs.html This puts them in the SW/Sailworks arena - for me. The NOlimitZ weblink disappeared - as usual - will start to copy and paste this type of data :-(
The weird thing is David Ezzy used to say any mast works with Ezzy sails - it's just a matter of performance. I do not understand - This is a very respected fellow. Some riggings look like crap and should not work at all :-(
Sailworks publishes their specs on their masts: http://www.sailworks.com/pdfs/Sailworks_Mast_Spex.pdf Barry Spanier of MauiSails says it is too difficult to put such precise numbers on mast specs. People are accusing Barry and MS of denying that their masts and sails are more hard top than ANY other windsurf sail.
do not take my word for it - investigate before mixing n matching. MauiSails says ok to their masts, Gaastra and Naish. For me right now masts, sails and boards are pricing themselves out of my range. i am having a hard time outbidding people for masts on e-bay !! Guess I will stick with what i got and try to fit the next sail 7.5 on my current 490 - SW Retro and 2010 Gaastra Matrix are ok.
Here is an extract from andersbq.com about masts: (anders is a swedish speed windsurfer)
For most sailors the recommended masts will do the work. Especially if you are into slalom and not are committed to find the extra knot on the top.
The general rule is light riders - soft masts, and heavy – stiffer. But remember it could be the opposite. When it comes to tuning the sail, it is good the have some ideas and basic knowledge in sail design. You also have to know what you are looking for. Low-end acceleration, middle-end acceleration, top-speed, control etc. I.e. the right mast can give you the turbo-kick you want when the gust comes!
Mast bases after the epoxy/fibreglass era have at least a standard nut to fit into a standard mast slot. They also have a pulley system in order to properly downhaul the sail - to sail maker specification. People use one-handed or two-handed downhaul tools, harnesses and winches for downhauling the sails. VERY IMPORTANT: DO NOT use a screwdriver of any sort !!! Many people have injured themselves and/or punched holes in their sails !!! Downhaul tension varies GREATLY between sail makers. North Sails makes a mast base with downhaul cinch.
Also, there are two (2) different pin mechanisms that must match the mast extension. There is the standard U.S. two(2) side pins and the Euro single pin in the middle. Some say we are going towards the Euro pin - it is just easier to put and take apart. I still use the U.S. two (2) pin system and have never had an issue except getting it apart when my hands are frozen. Some people have had the Euro pin come apart while sailing = woah.
When I started this blog, there was NO intention of making it a "complete" type of website. It was supposed to be a windsuring journal and nothing more. Guess I just got carried away.. In any case, if there is all this info, then I feel I must also list how to properly thread a pulley. I actually had to show my buddy who windsurfed shortboards longer than I :-( It makes it easier to downhaul and is just more efficient. So, here is my version of the threading:
How to thread “Streamline” Pulley
Start with thread down => for my old “homegrown” extension this means pulley on the right
- Thread up to sail pulley closest to mast – up the bottom and out the top
- Obviously thread up on that pulley
- Thread down middle extension pulley – at the mast side - from inside out
- Thread up outside that extension pulley – obviously
- Thread to outside sail pulley @ the top side - top down
- From top of sail pulley to outside of bottom extension pulley. - outside in
- Now up to middle sail pulley from bottom up
- And lastly up through the cleat .
- There may be some slight crossover on this extension since the start of the cord should actually be up higher….
For the mast extension where those pulleys line up with the sail pulleys, it is even easier to rig properly. Just keep putting the thread through the logical pulley on the logical side and make sure no lines cross or touch. At the left I have shown a simulation of where the pulleys at the base line up directly with the pulleys of the sail. When one does this with either of these setups, it makes the downhaul easier. Just the same I use a one-handed downhaul tool.An Italian has a new invention called the iDo to help people with masts and sails. It is a mast base that keeps the sail out of the water. It cannot handle big sails and one better attach the board to something cuz it could take off on its own :-)
The mast extension is not the same as original or older mast extensions and has better clamps to hold the mast up. Some surprisingly enough do NOT put markings on the holes !! Some have closer holes , like every 2 cm, to allow more flexibility. One fellow told me he will always stick to NP extensions because the cuff for the mast is just a little smaller and slides in and out of the sail so much easier. Each person seems to have their favourite based on experience or misfortune.
The ferrule is the part of the mast that goes from one part into the other tightly. This was a new word for me, butt apparently is a common part of the English language meaning ring or bushing :-)
Masts are expensive and critical. Choose wisely and handle with care.Word to the wise: keep sand out of the mast joint. Some people put electrical tape on the joint. Masts that are stuck together are NOT easy to take apart :-( I too started using electrical tape to join my mast pieces together when rigging. In my case it not helps keep the sand out, butt makes it MUCH easier to get the mast out of my cambered sails like my MS-2...
One thing I forgot to mention: it is important to measure your equipment. My 490 mast is actually 491 cm. This may not seem like much, but it is an indicator in terms of downhaul. One cm more or less of downhaul is definitely a difference one will feel out on the water... For downhaul I tend to stick close to manufacture specs, but for outhaul, I may go way under or way over - to see what I can get out of a sail :-)
Masts are expensive and MUST match your sail(s). They can get stuck together, crack and break - especially @ the ferrule IF you do not ensure the two(2) parts are completely together. My carbon masts cost me over $400. A 100% carbon mast can be close to $1000. There are used masts, but one needs to be careful and inspect the mast. The mast is the backbone and we all know how important that is and how much it can hurt !
