Yourbestsailvideo
The Backstay (part one)
October 2, 2023 · 12 min · 8K views
What this video covers
Tensioning the backstay on a fractional rig bends the mast forward at its center, stretching the mainsail's luff away from the leech across a wide surface area and flattening the sail more effectively than tensioning the cunningham alone.5:01 The mast's bend pivot point is where the forestay meets the spar; above that point the masthead moves aft under backstay load, below it the mast bows forward.4:29 Flattening reduces drive and also slackens the leech, increasing twist and depowering the upper sail — useful in freshening wind, particularly in racing where reefing is avoided.5:32 On cruising boats, the recommended response to increasing wind remains reefing early, not backstay adjustment.7:30 A secondary effect on fractional rigs is a modest increase in forestay tension, which reduces headsail sag and slightly flattens the genoa.11:12 One practical caution: on in-mast furling mainsails, the mast must be straightened before reefing, because a curved mast causes the sail to furl unevenly or jam.8:39 The distinction between full-hoist rigs (where backstay tension has little effect) and fractional rigs (where it is significant) is central to the explanation.1:32
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