Wouter,

You assume that the only difference is 15 % of wall thickness, I guess that with that difference you can have also lot more alloy in some parts of the section. As I said before I didn't do weighting with professional scales but I trust them more than your calculations where there is too many unknown variables. I'm planning to weight it better though when our season starts in few months, so let's continue with carbon alu differences then.

For now I'm disappointed about not getting a carbon mast because clearly there is big performance difference i.e. lot more in weight difference than 4 kg's when comparing carbon to masts that we have here. As a engineer you should understand that dragging those extra kilos high up in the air is not that wise and percentage in weight difference is more than in price <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />.