Originally Posted by SchockT
Another option for stabilizing your mast might be to relocate your chainplates aft, and sweeping your spreaders aft. I had a small race boat with a very bendy fractional rig, and it didn't need a backstay at all due to the aft swept spreaders. Of course it was a much simpler mast than what you have.
P.s. If you do end up buying a new mast, I have heard of people retrofitting the old IMS 40 mast with the newer and simpler Farr 40 rig.
Of course you could just train your crew better! Especially the runner guy!
If its the sail plan illustrated in the drawing, because of the jumpers at the top, it looks more like the 39 M/L. If so, there's nothing that a backstay will do other than open up the top of the main. There's no way to 'stiffen' the top of the rig. It's a great and very tweaky rig, but not one for anything less than an experienced crew. You need two runner guys in any sort of breeze, always, no exceptions.
The 'PS' part might be the best solution, but in any case, there's going to a lot of cost to make the structural changes (chain plate location, etc..) that are necessary. You might want to contact Hallspar or a similar spar maker and see what a new rig with swept back spreaders, etc... might cost. Honestly, I think the Farr office's answer was the correct one.