The first thing to address would be…
What is a rotating mast?
Uhh…well… it’s a mast that… uhhh… huh huh… rotates.
Ok… what is rotation? This is not addressed. Period. Depending on your rig, your mast may or may not rotate.
But Larry… the class rules say that I can’t have a rotating mast… Ok… how do you tell? Does your mast rotate? did you do it on purpose? Does it rotate on it’s own? Guess what… if the mast is not secured akin to a radio station antenna… it may well rotate… or twist…whether you mean for it to or not. If you have ever tied a load onto a car or truck… you probably found that unless you really knew what you were doing… there was still movement in the object. So… does your mast rotate? Probably.
Again… go carry a half a sheet of plywood in 10 kts of wind and come back and tell me if there is enough force to twist your mast around.
remember… FA=M The amount of reserve power in these boats is enormous… I had hold of one of my J boats, sitting in a 100 lb aluminum rowboat, with 450 lbs of crew (2), and a 95 lb Endeavour II… and holding it along side, she hit hull speed IN TWO LENGTHS HAULING A ROWBOAT @ 550 lbs, and the entire Woodlawn club saw it… we left a curling wake…
My diagrams show that with the sail track centred on the boat, the airflow around the leeward side of the mast is disturbed and will worsen as we go further offwind - effectively flattening the sail, which is wrong.
By the time you are off a beat, the airflow is not coming over the mast to get to the sail, and remember too… that even before you get to a full beam reach, the RW is deflecting aft because of the forward movement of the boat. You are dealing with deflection lift… NOT pressure imbalance at this point. The T-38 was the first a/c to fly from AoI alone (angle of incidence) and the only one with an ATC waiver for the 250 kts limitation below 10k because of it. and if anyone mentions Bernouli I will have a “teppicfresser” moment…
and… as pointed out above, you probably have some deflection in your mast. Rig your boat, grab your spreaders and give a tug… yoink… the mast twists… I bet… on a 72" spar, you could twist it 30 degrees, and not permanently bend it. (i.e. it would spring back)
I would have to ask in return though… if you are concerned about this phenomenom… what happens to the airflow on the lee side of the mast on a round shaped spar? That’s even worse!
Why are there carbon masts??? someone asks… didn’t specify full sized or model… so take your pick. Carbon carbon carbon… I want carbon… make sure that if you get a carbon mast, it is light… my shaped 72" aluminum mast is 4.6 oz and you will be using the most un-aerodynamic shape available…UNLESS… you can get a carbon airfoil shaped mast… which IS available… and wait till you see the price… anyway… carbon masts work on full sized boat because the savings in massive… it doesn’t work on models because you are already dealing with such a minute amount of weight. On something such as a Victoria, sure… the tapered carbon tube is far better than the aluminum tube that comes with the kit.
If you can sail your boat ounces won’t matter
If you can NOT sail your boat ounces won’t save you
Think MODEL… this is not a full sized boat. It can tack in 1 second and therefore stitch a course to the weather mark that a full size boat cannot begin to approach. IOM’s can tack and not even lose 25% of their speed.
The bottom line here is obvious too… if you don’t like it… DON’T USE IT… I am just putting it out there for you to see… AND CHOSE… don’t believe me… think I am nuts… don’t have a clue… OK!!! not a problem, you are NOT alone… there are a lot of guys out there that don’t believe me… If you think round is better… knock yourself out…that is what makes it great… you can do anything you like with your boat.
My job is to bring the best available hardware I can manage to make the boats go fast… I do this 7 days a week and have a lot of time and a FORTUNE invested. I just want to help you go fast, it is that simple. If it didn’t work… I would not recommend it… I would say… I DON’T KNOW… it should tell you something… that considering this is my full time employment… if it didn’t work… I would not be willing to put my name on it.
It doesn’t matter to me which is better… what matters is getting it to the racing skipper. If Easter eggs and gardenhose would make a better boat… buddy… I would use them.
I have many, many skippers that call me and thank me…
I have NEVER had one switch back. * EVER *
If you don’t believe me… about using a sailtrack mast… because I am a bozo…talk to Graham Bantock and ask him why he had his IOM round mast made (Groovy) with a sailtrack… if he isn’t out winning ANOTHER National Championship he will be glad to talk with you… and I bet it is the exact same reason I had mine made (albeit with a different internal design for shaping)