I've been impressed lately with the difference a 100% late model mast makes to the performance of my bigger sails so am planning to upgrade my 400 to 100%. I've never used an RDM, is the performance, longevity or otherwise worth the extra expense of having to get an RDM extension as well?

I have used RDM from 2000. I use in all Sails now, my largest is 7.0. When I had a 8.5 Lion with Ezzy 490, the SDM at 100% was better for me. 7.5 was a toss up.
Smaller sails , like the 400 would fit, I always use the skinny.
Several negative to RDM, they sink faster, hurt more when hit on the head( pointier) wear helmet alleviate that, grip when tacking, is a +-, depends on hand size, slightly less reflex when really powered up, a personal reflection.
Positives , easy to rig , better lo wind performance , stronger.

yes you need a RDM EXT.
If you need the 400 anyway, def get it, if not def get it anyway.

i also have a few different RDMs, powerex, no limits, Maverx, Ezzy , Hot Sails. The Ultra light versions, do offer better performance, I would not lay out the $$ for 1 , to use on 1 sail only, unless you have very deep pockets.

RDM only feel lighter, in fact most of the time they are slightly heavier.
But also close to unbreakable so very reassuring when sailing in open ocean.

NotWal said..
You can run an RDM in a standard extension if you want to. It's just a little inconvenient to adjust and you may have to cobble a through pin and a mast base plug for the mast to sit on.
Oh yes, and it may intefere with the bottom camber inducer if you use such things.

These were made , oh 2001 or so. They weren't very effective . I have one still, waiting for it to become vintage so I can sell it on ebay

forceten said..

NotWal said..
You can run an RDM in a standard extension if you want to. It's just a little inconvenient to adjust and you may have to cobble a through pin and a mast base plug for the mast to sit on.
Oh yes, and it may intefere with the bottom camber inducer if you use such things.

These were made , oh 2001 or so. They weren't very effective . I have one still, waiting for it to become vintage so I can sell it on ebay

What was, and why wasn't it effective?

I have Ezzy Hookipa RDMs, and notice huge improvements every where in my sailing from SDMs. But my old SDMs weren't mostly all carbon content Like Ezzy masts are. Like I said, from lighter, to easier manoeuvring. They slide in the sail sleeve much easier. Especially if you have Ezzy sails, it's a windsurfing wet dream! Lol!

forceten said..

NotWal said..

forceten said..

NotWal said..
You can run an RDM in a standard extension if you want to. It's just a little inconvenient to adjust and you may have to cobble a through pin and a mast base plug for the mast to sit on.
Oh yes, and it may intefere with the bottom camber inducer if you use such things.

These were made , oh 2001 or so. They weren't very effective . I have one still, waiting for it to become vintage so I can sell it on ebay

What was, and why wasn't it effective?

Was ..a adapter to use a RDM mast, on a SDM extension. Had a collar with inner diameter to match the RDMs, a pyramid cone ,that went inside the collar,and then was supported by the pin through the holes in the extension.
About the same as it was on the market the first RDM extension , that I remember, by Windsurf HAWAII, came out, which had different sized sleeves to make elevated adjustments. Both were crap.

I have one of those plastic cone things that sits on the through pin and I wouldn't call it either "ineffective" or "crap", just a little inconvenient as I said earlier.
The OP asked if a rdm extension was necessary and it isn't. He can safely get an RDM and not have to buy an extension.

These are the type of adaptor discussed. I have one, but have never used it as my SDM extensions don't use pins so it won't work.

www.surfsailaustralia.com.au/product/chinook-skinny-adaptor-kit#surf-sail-clothing-hardware

NotWal said..

forceten said..

NotWal said..

forceten said..

NotWal said..
You can run an RDM in a standard extension if you want to. It's just a little inconvenient to adjust and you may have to cobble a through pin and a mast base plug for the mast to sit on.
Oh yes, and it may intefere with the bottom camber inducer if you use such things.

These were made , oh 2001 or so. They weren't very effective . I have one still, waiting for it to become vintage so I can sell it on ebay

What was, and why wasn't it effective?

Was ..a adapter to use a RDM mast, on a SDM extension. Had a collar with inner diameter to match the RDMs, a pyramid cone ,that went inside the collar,and then was supported by the pin through the holes in the extension.
About the same as it was on the market the first RDM extension , that I remember, by Windsurf HAWAII, came out, which had different sized sleeves to make elevated adjustments. Both were crap.

I have one of those plastic cone things that sits on the through pin and I wouldn't call it either "ineffective" or "crap", just a little inconvenient as I said earlier.
The OP asked if a rdm extension was necessary and it isn't. He can safely get an RDM and not have to buy an extension.

I didn't think you could even purchase one now. You need the SDM with holes / pins .I reckon your definition of crap and inconvenient differ from mine. Unsure that the RDM inside the SDM is without fault. I reckon I could ask David Ezzy.

Orange Whip said..
I've been impressed lately with the difference a 100% late model mast makes to the performance of my bigger sails so am planning to upgrade my 400 to 100%. I've never used an RDM, is the performance, longevity or otherwise worth the extra expense of having to get an RDM extension as well?

Reread the OP with question and intent. 400 masts don't fit my larger/ bigger sails , my 400 fits my 5.6
Is it worth the extra expense of an RDM extension ?yes. Hell yes.

is it worth the money to purchase a SDM to RDM adapter kit, not my money.

choco said..

seanhogan said..
RDM only feel lighter, in fact most of the time they are slightly heavier.
But also close to unbreakable so very reassuring when sailing in open ocean.

No the're not

missing something there.....