Swept back spreaders

[DEAN2140]

I know that swept back spreaders are sometimes used to eliminate the need for a back stay (see Hunters) but most monohulls that use them still retain the backstay. Given that they restrict your ability to sail downwind, can someone explain why so many boats still use them?

[billknny]

Originally Posted by DEAN2140

I know that swept back spreaders are sometimes used to eliminate the need for a back stay (see Hunters) but most monohulls that use them still retain the backstay. Given that they restrict your ability to sail downwind, can someone explain why so many boats still use them?

They are not an old design that boats "still use," rather they are a modern feature. They add a lot of fore/aft stiffness to thin, "bendy" masts that are common on racing boats (and wannbe racers). They also help control mast bend to keep things in column when the backstay is tightened to bend the mast. The limitations they impose on mainsail trim on the race course are not significant. Buoy racers (almost) never sail on a run.

Now for the controversial editorial: If you want to have a robust boat, suitable for sailing anywhere in the world far away from repairs and support, they are a "feature" I'd try to avoid. Not so much for themselves, but for the kind of mast they are used on. Yes, I understand the benefits that thin, lightweight, bendy masts give a sailboat. If I was a local or coastal cruiser I'd warm to the idea. But they come with a cost I would prefer not to pay for an offshore boat.

[boom23]

All Amel boats will disagree with you... They don't have thin & bendy masts. They have a robust mast with in-mast furling and swept back spreaders.

[Pauls]

A small amount of spreader sweep - say up to 12 degrees or so - is a good feature that helps stabilize the mast fore/aft. When the sweep is increased to 25 to 30 degrees then there is enough support to allow the elimination of standing back stays. Allows clearance for a big roach or the gaff on a gaff rigger. Like everything on a sailboat, it is a compromise, in this case it reduces how far the main can be boomed out. going from say 65 degrees boomed out main to 90 degrees does increase dead downwind sail area some, but not that much.

[billknny]

Originally Posted by boom23

All Amel boats will disagree with you... They don't have thin & bendy masts. They have a robust mast with in-mast furling and swept back spreaders.

Yes, about 4 inches of displacement aft. I think we can both agree(?) that is NOT what we are talking about here.

[Pizzazz]

The B&R rig used on the Hunters has many benefits and a few compromises. It really depends on how you sail. Overall, it is claimed that the rig is optimal for upwind sailing (thin mast, prebend, the swept spreaders allow sheeting in the Genoa very tight.

Dead downwind, it is not optimal but the penalty is not dramatic either. Furthermore, dead downwind one should fly a spinnaker or sail on a broad reach and gybe. VMG will be higher.

The backstay is not necessary and if your rig is tuned well (both the prebend that you do with the mast down and the stays), you can just remove it. I keep mine as an SSB antenna but I have sailed without it and could not notice any difference. The rig looks complicated but it is simple to adjust by hand at sea once you do it a couple of times in different conditions.

[malbert73]

If you are cruising and don’t fly a screecher or chute, dead downwind (especially with poled out genoa wing on wing) will always be quicker than gybing downwind. This is because the higher angle required to fill a blanketed genoa will be slower VMG. But a poled our chute will make deep gybing angles faster.

So severely swept spreaders will really increase chafe and reduce ability to square off a mainsail downwind.