Tim wrote:
Hello,
I recently bought a Space Sailer 22 ... (snippage for brevity)...
... I am considering replacing these halyards with
Spectra.

My question is - If I replace these halyards with spectra will I need
to replace the blocks at the top of the mast??

If you're going to the expense of using Spectra, yes. This will only add
a tiny fraction to the cost, although a good bit more to the work load.
It would also be a good way to ensure that the halyard sheaves are
properly turning. You may want to replace the pins or bushings too. In
my experience, work expended on the mast, it's head, & it's guts, amply
repaid for itself in less trouble aloft later.

The best replacement would be Spectra tapered into tails with Spectra
core inside poly covers, for better handling. On a 22 footer the weight
saved will not be significant, but they'll run a lot easier than wire
and less stretch & creep. Also Spectra won't have meathooks and won't
saw through things like wire.

Fresh Breezes- Doug King