arithmetic for shorter spreaders...

[ALX357]

well here is another reason shortening the spreaders is a BAD idea, just so you know i have asked second, third and so forth opinions....
if the angle of the outer stay changes from parallel to the mast, leaning inward to the spreader tips, the compressive forces would be bending the spreader downward, probably alot, instead of just inward compression as it is now.
Do all shrouds with spreaders run parallel to their masts ? probably so.

[dclark]

You don't need to be an engineer, you just need to remember it's a MacGregor and follow the dollar. In this case, the longer the spreader, the greater the cost. Therefore the spreader they gave you is as short as it can safely be.

[ALX357]

..'just noticed something to add to this old thread... by the way, a search of "shortening spreaders" (both words together) yields 3 threads, one locked, one that describes several successful mods, with no ill effects apparently and with at least one boat rigger's approval, and then this thread, where everyone warns vehemently against the shortening of spreaders.
The objections here (above posts) are mainly that Roger would not have made them as long if they could have been shorter. Engineers should not be satisfied with that kind of explanation, even if we (of lesser technical education) might reason so.
One additional bit of input here.... the posted photo below shows my MacX next to a ratty but intact S2, which I believe is a fast, race-worthy boat, maybe heavier duty, I don't know, but surely designed and built to take the tremendous stress of hard sailing.
Look at the spreader length.
...its mast actually a bit taller, considering the step height above water, and the chain-plate width (between port and stbd.) less than the Mac.
Unless the materials are vastly stronger (SS wire, plates, hull ) the design would seem to be weaker than the alleged marginally sufficient Mac. That can't be, in a tried and tested design such as the superior sailing S2, so I am led back to the idea that the MacX's spreaders would be able to be shortened without materially weakening the rig. Still NOT SURE about this, but the photo provides an interesting comparison.

Note the raised Genny and its raised head attachment, been almost six months without any problems sailing, have had extended heeling winds for several miles.

Makes for alot better visibility, day and NIGHT, and allows for attachment of lifelines at upper point of bow pulpit, plus room for a lever-assisted furler tensioner rigged from standard Mac parts. (As modified and described in another thread and also in the original thread by another Mac owner from which I adapted mine.)