Torrid, I've taken that for granted, as no one's ever even hinted otherwise.
When the carbon topmast was first proposed back in 1999 (and defeated in the same vote that approved the current control systems), it was intended for the Radial rig only. It was supposed to work together with a slightly re-cut Radial sail to be nicer for lighter sailors. (That sail, the Mark 6 Radial with the blue corners, was adopted anyway.) The development of that spar was done by Takao Otani; how different or similar it was to the one whose release we're now waiting, I don't know. Anyway, it probably wouldn't have taken long for it to be legalized on the other rigs as well... and that's why I voted for it at the time.
With that historical background, I have assumed that any restrictions by rig would have been mentioned by now.
I had forgotten about the previous go-round with a carbon upper.
My recollection of the discussion for the current proposal is a carbon upper with the same bend characteristics as the current aluminum one, the intent being the same performance but improved durability. Much like the new full sail.
Sounds like the intent is exactly like the sail, a drop-in replacement with the same performance but better durability. When and if it is approved, there is probably no reason to rush out and buy one until your current aluminum upper breaks. Note the article is from four years ago, with the same hang-ups as the mkII sail.
Yes, this is what I've been thinking as well. Unless you're bored with straightening your current mast after every time you've used it.
Collectively, the composite construction should end the mast bend checks at major regattas. Cherry-picking topmasts should also become pointless as the quality will be much more uniform.
Basically yes, as you can control the amount of fibre and resin that goes into each tube. With aluminium, I understand that because of the construction process, the first and last products of a batch will by necessity have different wall thicknesses. The only way around it is smaller batches, which of course raises the price per unit.
(I am by no means an expert on this; I should probably ask for more details from a friend who was involved in building Lightning spars a few years ago.)
So much of what used to fail was because of poor quality control from the factories or suppliers having not been told what the class rules were. Sleeves not being properly located, hiking straps with 2 loops, fittings not correctly located. Measurement checks are not just about seeing what the competitor has done but what is being supplied to the competitors.