Hunter 35.5 Legend back stay rigging.

FrKim

.
Jun 21, 2021
14
Hunter 35.5 Legend Erie
Should the back stay be tight to the point of inducing an aft bend in the mast between the fore stay attach point on the mast and the top of the mast.
The rigging instructions in the Hunter Manual seem pretty vague. It does not mention bend in the mast except for " tighten upper shrouds until there is approx. 1" of 'per-bend' in the mast, fore and aft."
Mine seems to have more than 1" pre-bend as well as additional aft bend above the fore stay attach point.
I did back off the back stay a bit to reduce the bend in the top of the mast.
I attached a picture of my mast and a drawing. the bend in the drawing is exaugurated.
Thanks for your thoughts
 

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Jan 1, 2006
7,039
Slickcraft 26 Sailfish
The forestay sets mast rake. If you were satisfied with balance of the helm with the previous length and not as much so with the new length, go back to the previous length. On fractional rigs, and less so with the B&R rig, the mast bend is induced by tension on the backstay. If your sail is cut for it bending the mast will flatten the sail and de-power it. Also, bend will increase forestay tension reducing curve in the forestay luff and de-powering it.
Pre-bend is tuned into the mast with rigging adjustment. Again, it should match the luff curve of the mainsail. Furling mains shouldn't have pre-bend.
I admit I don't really know why sailmakers put a luff curve on a mainsail. But if they did you need for the mast to mimic it.
I had a 356 with the B&R rig with NO backstay. So I don't have first hand experience with mast bend with that rig. It seemed to me that the mast was pretty beefy (I had the roller main) and well supported with rigging. I wouldn't expect the mast to bend that readily. But you could tension the forestay. On the 356 I couldn't do that and I think to the detriment of upwind performance in winds over 12 Kts.
 

FrKim

.
Jun 21, 2021
14
Hunter 35.5 Legend Erie
The forestay sets mast rake. If you were satisfied with balance of the helm with the previous length and not as much so with the new length, go back to the previous length. On fractional rigs, and less so with the B&R rig, the mast bend is induced by tension on the backstay. If your sail is cut for it bending the mast will flatten the sail and de-power it. Also, bend will increase forestay tension reducing curve in the forestay luff and de-powering it.
Pre-bend is tuned into the mast with rigging adjustment. Again, it should match the luff curve of the mainsail. Furling mains shouldn't have pre-bend.
I admit I don't really know why sailmakers put a luff curve on a mainsail. But if they did you need for the mast to mimic it.
I had a 356 with the B&R rig with NO backstay. So I don't have first hand experience with mast bend with that rig. It seemed to me that the mast was pretty beefy (I had the roller main) and well supported with rigging. I wouldn't expect the mast to bend that readily. But you could tension the forestay. On the 356 I couldn't do that and I think to the detriment of upwind performance in winds over 12 Kts.
thank you Andrew