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techno900
Joined: 28 Mar 2001 Posts: 4161
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Posted: Wed Apr 03, 2013 8:14 am Post subject: |
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In other words, there is a reason that the PWA slalom racers use SDM.
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DanWeiss
Joined: 24 Jun 2008 Posts: 2296 Location: Connecticut, USA
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Posted: Wed Apr 03, 2013 8:29 am Post subject: |
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I gotta agree with LeeD on this last point. From a practical performance standpoint, std diameter masts perform far better for racing at high apparent wind speeds. This is due, in part, to the inability of rdm masts to maintain sufficient stiffness and reflex response when in high compression. Cams can be adapted to fit rdm masts, I've done so myself, but std masts almost always maintain control when lit up beyond their rdm comparators.
There are plenty of very fast sails using rdms. But the perceived gain in reducing entry radius doesn't seem to payoff as a net gain in reduced drag for sails that must accelerate out of the hole and operate in wildly swinging apparent wind angles like experienced in high-level slalom racing.
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U2U2U2
Joined: 06 Jul 2001 Posts: 5467 Location: Shipsterns Bluff, Tasmania. Colorado
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Posted: Wed Apr 03, 2013 9:04 am Post subject: |
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The MaverX Stilo RDM masts are renowned as some of the toughest on the planet but not only are they one of the strongest masts but they have the performance that helped Finian Maynard break the World Speed Record.
RDM used.
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U2U2U2
Joined: 06 Jul 2001 Posts: 5467 Location: Shipsterns Bluff, Tasmania. Colorado
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Posted: Wed Apr 03, 2013 9:21 am Post subject: |
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zirtaeb wrote: | Are you still braindead?
Like the mast base post?
15-22, if you want to go fast, you rig a 7 meter slalom sail.
Said sail don't rig on RDM, right?
RDM's have thicker wall, can resist impacts OK.
SDM's have thinner walls, think before you stuff your head into the sand! |
You ,mistook my sarcasm for not understanding what you wrote, in the first posting. You have mostly generalizations that a SDM will be faster than a RDM then cite wind speed and now sail size. That a RDM will be stronger than a SDM, agree , you make it sound like any SDM will break in a shore washing, and dropping one is cause for alarm
I would question some of the newer 60% carbon offerings being as strong, but a comparable carbon % the RDM should be stronger.
Masts are going to break, whether they come in black or silver, are made in China or Italy .
z lee or who ever you are today,
on a GT mast question this was your answer::
https://www.iwindsurf.com/forums/viewtopic.php?t=25748&highlight=masts
** They should rig on any sail that can take an RDM mast, and most sails that don't.****
This without any knowledge of the mast bend curve other than a constant curve as quoted by the seller.
Your lack of what to me is basic mast bend curve knowledge is only exceeded by your other humane qualities.
the mast base question was resolved by some other helpful posters, several made PMs to help out. Iam still shocked that you would expect thanks for unwarranted rude remarks.
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capetonian
Joined: 11 Aug 2006 Posts: 1197 Location: Florida
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Posted: Wed Apr 03, 2013 9:59 am Post subject: |
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zirtaeb wrote: | Try going fast in 15-22mph winds with a RDM, and you'll get smoked by SDM's.
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That used to be accepted knowledge back when accepted knowledge was that the earth was flat. Both Loft and HSM are making competitive race sails designed around RDMs.
I'm heavier than most I sail against, and our local winds are in the 15-20 mph range, yet I'm competitive on my RDM rigged 8.0 race sail against other sailors on North Warp, Maui Sails TR and NP. (Most of us are using iSonics, Nelson or Mikes Lab).
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3-phase
Joined: 26 Jan 2007 Posts: 481
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Posted: Wed Apr 03, 2013 12:18 pm Post subject: |
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OP achieved his goal this starts to look like a gear review haha.
On our KA Sails, the Freeride / Slalom sails Koyote rig on RDM or SDM up to 8.2 meter it rigs and sails great on an RDM mast but the 6.6, 7.4 and 8.2 have 10-15 % more power with a 75% - 100% SDM Mast.
On the Slalom / Speed Sail the KA Koncept up to 5.8 they work great o RDM Mast, 6.6 and bigger they will go faster and have more power with a SDM mast 75 to 100%.
Important to know a SDM mast has by physics law the better response stiffness then a RDM Mast.
Mast for RDM anything less the 90 % even you save money I don't really think you getting all out of your sail you could.
SDM I believe should be at least 75 % carbon to getting it going well.
Capetonion Hot Sail Maui teamrider has a Physical advantage he is tall and fit that helps with Race and Speed sails to have the leverage holding a bigger sail versus us short and fat guy's
Jurg
www.windsurfdeal.com
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adywind
Joined: 08 Jan 2012 Posts: 665
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3-phase
Joined: 26 Jan 2007 Posts: 481
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DanWeiss
Joined: 24 Jun 2008 Posts: 2296 Location: Connecticut, USA
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Posted: Thu Apr 04, 2013 10:15 am Post subject: |
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Two different conversations about RDM performance: Normal, high-end performance as high as PWA slalom racing almost always finds standard diameter masts the clear leader.
Finite use in a limited range of wind angles and water conditions allows one to optimize around an RDM. Finian's speed sails are shaped nothing like racing sail but for rough appearance. They have less depth, a farther aft draft location and less twist. They operate in narrow conditions that include very, very flat water, fairly undisturbed wind and an apparent wind angle that is farther aft than what we might perceive when thinking about windsurfing near 60 mph. But its the consistent apparent wind angle and small sail sizes that allow for the RDM use that otherwise would be too critical.
When I rig a 5.8 wave sail on an RDM, it feels lighter and more slippery and must be sailed differently than when rigged on a standard diameter. The std mast allows the sail to generate more power in more situations and I can keep the hammer down when going upwind and deeper downwind in chop without feeling I'm on the edge. That's not the case with the RDM. That mast requires me to feather the sail going upwind and simply runs out of steam downwind and in very wide arc jibes. All OK, but different limitations.
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dllee
Joined: 03 Jul 2009 Posts: 5329 Location: East Bay
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Posted: Thu Apr 04, 2013 3:10 pm Post subject: |
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Problem with Andywind's picture...
Anyone who can sail will stay with him on a 5.5, maybe pass him on a 6.0 with a slalom board.
Why destroy your 7+ sail in winds of 18-28, when a smaller sail goes just as fast, jibes better, lasts longer, and is easier to sail?
At 162 lbs. and a 4/3 wetsuit, I can easily hold my 6.5 race sails when the gusts hit 30, but I'll sail for 2 hours comfortably, go just as fast, on a 5.0, jump over everyone's masts, and actually have FUN out there.
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