I thought 700-800 lbs of tension was the top end of the scale for my N20 (carbon mast).

Higher diamond tension would (I guess) reduce the leeward bend of the mast under tension (at least up to where the diamonds meet the mast) as well, no?

FWIW, on our current Infusion we're running 600lbs for our base setting, and 900lbs once it goes above 15knots sustained. Less for super light conditions, and more when it's nuking

Yes there is, but you go about it sort of backwards from the way you stated it. The process goes something like this:

With the mast already tensioned, remove the diamond wire on one side by pulling with two hands and pushing the diamond spreader portion of the mast with one or two of your feet. Two if seated, one if standing.

Tighten up the wires some more (make a guess) and then use the same bowing technique to replace the diamond wire onto the spreader tip.

Measure and repeat as necessary. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Turning the turnbuckles when they are fully loaded is asking for galling and seizure in the turnbuckle bolts.

GARY

Like I said...

Question:
You only want the curve of the mast to match the luff curve when the downhaul is maxed out, correct? If you made it so that the mast had the luff curve at no downhaul then wouldn't downhauling do nothing to depower the sail? because the sail would be board flat to start with.

When one does a diamond wire adjustment, do you care whether the endcap that holds the diamond wire at the spreader is loosened?

I assume you are talking about the little screws that pinch the wire on the spreader tips. I would loosen them and keep an eye on how much adjusting the tension on the diamonds deflects the spreaders. you will have to bang them up or down the diamonds a little to recenter them after you have changed the tension. I went through this on my 6.0 but there was no captive mechanism - other than a slot- on the spreader tips. After it was all set, you use seizing wire.

when I got my mast back from Mischa at the end of last years t500, there was 950 lbs of diamond tension on my mast.

needless to say I thought he was crazy, but it seems to be something thats being done.

Yes, those...just thought it would be easier if you didn't have to adjust those, then you wouldn't [necessarily] have to put your boat on its side.

If you wind up your wires to 900lbs of tension then banging on the spreaders is probably a bad idea - you want to keep them in compression and not deflect them out of column with all that force on them. You can set up the spreaders so they are pointing up slightly, and they then come back perpendicular to the mast when you apply full tension to the diamond wires.