Bit of a silly topic perhaps, but curious if I am missing anything:

Assuming the sail has correct downhaul tension, are there are any changes/consequences to be expected when the entire rig is, say, 4cm higher than it would be if it were pulley-to-pulley at the bottom?

For a simplistic example, if the downhaul number is 374, you can rig a 370 with 4cm extension and pull all the way down to the bottom pulley. Or if you had 8cm extension, you can downhaul until you are 4cm from the pulley. The sail has the same tension/shape in either case. Your body is now 4cm lower at any given point on the sail, which should be mostly irrelevant unless you got silly with the number.

Is there anything else that will happen doing this vs. rigging with the minimal base extension? There are a few different reasons for doing this, one of them is that on some very tiny sails the boom cutout is too low. Raising the whole rig allows me to have the correct boom height. I've done it countless times with one particular sail and its seems no different to me.

In theory a gap between sail and board, decreases sail efficiency. how much practical effect that has is anybody's guess.

I find that when using a Power XT extension you have to leave at least an extra couple of cm otherwise de-rigging the XT will be problematic. Is this what other Power XT users have found?

On my old sails, especially on my smaller one (4.2) I like to have it set a little higher to catch more wind up top. Modern sails don't matter as much. It's nice to have it close to the deck but not a necessity.

vosadrian said..
I have power XT and normally add 2cm to the recommended luff length. This makes it a little easier to work with the XT release and also allows for more downhaul if required. The great thing about the XT is it is so easy to add more downhaul on the water. 2cm extra gives me enough to get to max downhaul on my sails and still have a bit to spare to enable a bit more lever pressure to change the lever switch from tightening to loosening.

One point worth mentioning is I use the XT base/tendon also which is pretty low profile and mounts the extension pretty close to the board compared to others.

Power XT are ace.

I have got a Duotone 6.2m super star sail, it set with 2cm less extension and 4 cm less outhaul then the printed measurements on the sail. I have tried it to their measurements but its dead flat and too twisty.

That was 15 years ago and being used by a beginner so hard to say what went wrong. I used the original one and now using the 2.0 version. Never had a problem other than once I needed to replace the line because it was slipping. You have to get the OEM because it’s a tad thicker than what non-Duotones are (5.2mm v 5mm or something like that). I have yet to meet a person who has tried them and gone back to regular ones.

gandalf99 said..
Bit of a silly topic perhaps, but curious if I am missing anything:

Assuming the sail has correct downhaul tension, are there are any changes/consequences to be expected when the entire rig is, say, 4cm higher than it would be if it were pulley-to-pulley at the bottom?

For a simplistic example, if the downhaul number is 374, you can rig a 370 with 4cm extension and pull all the way down to the bottom pulley. Or if you had 8cm extension, you can downhaul until you are 4cm from the pulley. The sail has the same tension/shape in either case. Your body is now 4cm lower at any given point on the sail, which should be mostly irrelevant unless you got silly with the number.

Is there anything else that will happen doing this vs. rigging with the minimal base extension? There are a few different reasons for doing this, one of them is that on some very tiny sails the boom cutout is too low. Raising the whole rig allows me to have the correct boom height. I've done it countless times with one particular sail and its seems no different to me.

I can’t see much of an issue doing this. A lot of people set +2 on their extensions so they can go +1 if it’s cranking. Or if your sail has odd numbers on downhaul length and your extension is even numbers you can’t go block to block. Important part of your post is that you are applying the correct downhaul.

If you are using a much longer extension to allow the extra 4cm then this is not ideal as the extra extension length changes the mast bend curve. You will notice most sail sizes are designed to work on shorter extensions. This is done on purpose by the sail designers.

Can’t see how outhaul would be different as everything is going up 4cm.

Needing to add 4cm does seem odd though. Are you using sails designed with lower clews and boom cutouts like the severne redback?.

Gestalt said..

Needing to add 4cm does seem odd though. Are you using sails designed with lower clews and boom cutouts like the severne redback?.

I use Hot Sails KS3. On the smaller ones (3.1, 3.4), the boom cutout is lower than I'd prefer for the boom height I want, but just +2cm makes enough room. I have then been rigging most of my other sails at +2cm base just so I don't have to adjust the thing.

But I have ONE sail that needs +4cm...so I figured I'd just run them all at +4cm. Like I said, kinda silly...

3 - 20 mm remaining to play with downhaul are enough for me with a Power XT 2.0.

Never adjusted Downhaul more than two clicks on the water - in both directions (Warp Fin).
With 3 mm remaining I can also release it using -.

Dude the difference over 10m is about a knot or two.
You are not feeling 4cm

Windshear calculators avail online. Yes there is a greater difference between water level and 4m up, than say 10m vs 14m. . Yes having more sail above waves is great. But if it made that much difference we'd see speed sailors arguing over recessed decks vs actual data for speed - and we don't.

I still call BS

For sails with an unusually low foot, especially on foil, it's a really good idea to keep 4cm between the pulleys. The reason is that otherwise if you try to fast-tack or foil-tack with the sail all the way down the foot will foul on the rear footstraps. You'll still have no problem closing the gap on reaches.

utcminusfour said..
If there is not a tack strap in use, then any distance between the pulleys will increase twist.

There's hardly any wind down there of significance anyway. That said the old sails are cut lower aren't they?

WillyWind said..
That was 15 years ago and being used by a beginner so hard to say what went wrong. I used the original one and now using the 2.0 version. Never had a problem other than once I needed to replace the line because it was slipping. You have to get the OEM because it’s a tad thicker than what non-Duotones are (5.2mm v 5mm or something like that). I have yet to meet a person who has tried them and gone back to regular ones.

I used a Duotone Power XT for a couple of years (I had two!), then they both started slipping and I never bothered to repair them, so I went back to a much simpler standard mast extension that I could trust. I've absolutely no interest in going back to the Power XT.

I tend to set my downhaul once on the beach and just forget about it. I always use a setting near maximum downhaul anyway, which is my overall preference to suit my riding style. Once or twice when I've been caught out by the wind suddenly nuking, I've been able to crank more DH while on the water and the rig still attached to the board, using my harness. To my mind, the Power XT just adds unnecessary complication, it's just another thing that *could* fail on the water. To my eye at least - the XT mechanism itself also raises the effective height of the pulley block and hence the whole rig, by about 2 cm - compared to a simple conventional extension downhaul pulley. The only place I could see a Power XT being potentially useful is tuning windfoil gear while out on the water.

Overall comment though: This thread has gone really weird 😂

AoetearoaSailor said..

WillyWind said..
That was 15 years ago and being used by a beginner so hard to say what went wrong. I used the original one and now using the 2.0 version. Never had a problem other than once I needed to replace the line because it was slipping. You have to get the OEM because it’s a tad thicker than what non-Duotones are (5.2mm v 5mm or something like that). I have yet to meet a person who has tried them and gone back to regular ones.

I used a Duotone Power XT for a couple of years (I had two!), then they both started slipping and I never bothered to repair them, so I went back to a much simpler standard mast extension that I could trust. I've absolutely no interest in going back to the Power XT.

Clearly it is a bit of an individual thing. I am a fairly recent adopter of the XT with about 1 season so far. It has been a revelation for me. I have a dodgy back and for many years have used a rig winch which worked fine, but if I needed to add extra downhaul on the beach I had to go to the car to get the winch... or risk a back problem without. Now I have no need for any tools and can add downhaul without removing the rig from the board. Threading the line in the sail is quicker. It is just a better experience all around. I expect after a few seasons it will slip, but I don't think replacing the rop every few seasons is a big deal for general maintenence. I wish I made the change years ago!