Jumper Strut 35.5
- Thread starter MikeL
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Mike:
I looked the Jumper Strut up and now I know what it is, but I wonder why you want one?
I think you have an Isomat spar on your boat. Rig-rite lists them for Kenyon spars. You may want to try Seco South (Hunter OEM provider) in Fl. and see if they have any advise for you.
I looked the Jumper Strut up and now I know what it is, but I wonder why you want one?
I think you have an Isomat spar on your boat. Rig-rite lists them for Kenyon spars. You may want to try Seco South (Hunter OEM provider) in Fl. and see if they have any advise for you.
Mike,
I checked with RigRite and they do not list the jumper strut on their web site but they can make you one for the Isomat mast section NG 51 which I believe your boat uses. I would need to send them a picture and dimensions of mine to copy. If interested let me know.
I checked with RigRite and they do not list the jumper strut on their web site but they can make you one for the Isomat mast section NG 51 which I believe your boat uses. I would need to send them a picture and dimensions of mine to copy. If interested let me know.
Mike
Here are a couple of pics of the jumper strut. I'll have to wait for some descent weather before I go up the mast to take dimensions off it. When I get them I'll send them to you and you can forward them to RigRite. Their email is rigrite@gmx.com They requested that you should include the make and model of the boat in the subject line.
Cheers
Here are a couple of pics of the jumper strut. I'll have to wait for some descent weather before I go up the mast to take dimensions off it. When I get them I'll send them to you and you can forward them to RigRite. Their email is rigrite@gmx.com They requested that you should include the make and model of the boat in the subject line.
Cheers
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To everyone with a fractional rig.......
...you should know that tensioning your backstay adjuster does almost nothing to increase headstay tension. It does bend the mast flattening the main. The only way to increase headstay tension for upwind sailing is with either running backstays or a jumper strut combined with a backstay tensioner. Conveniently bending the mast and tensioning the headstay are both adjustments that would be needed when sailing up hill in increasing winds. Likewise when reaching or running, easing the backstay straightens the mast and allows the headstay to sag inducing the proper sail shape for that condition.
...you should know that tensioning your backstay adjuster does almost nothing to increase headstay tension. It does bend the mast flattening the main. The only way to increase headstay tension for upwind sailing is with either running backstays or a jumper strut combined with a backstay tensioner. Conveniently bending the mast and tensioning the headstay are both adjustments that would be needed when sailing up hill in increasing winds. Likewise when reaching or running, easing the backstay straightens the mast and allows the headstay to sag inducing the proper sail shape for that condition.
Alan and Mike,
Wow, this is very timely. Have not been on this site for a year. Too busy winning trophies, thanks to Alan's great advice.
I just decided to check back in to see about jumper struts, as I too am tired of the haeadstay sag and tightening uppers so much that it scares me.
Mike, have you gotten anything back from Rigrite on this? Maybe we can get the specs from Alan and get a deal on making 2 sets of jumpers. Some other owners may want in as well.
Also, do I understand that you have a set of VPP's? Would love to get my hands on them! What is your handicap up there?
Cheers, George (1991 Hunter 35.5 - PROMETHEUS)
Wow, this is very timely. Have not been on this site for a year. Too busy winning trophies, thanks to Alan's great advice.
I just decided to check back in to see about jumper struts, as I too am tired of the haeadstay sag and tightening uppers so much that it scares me.
Mike, have you gotten anything back from Rigrite on this? Maybe we can get the specs from Alan and get a deal on making 2 sets of jumpers. Some other owners may want in as well.
Also, do I understand that you have a set of VPP's? Would love to get my hands on them! What is your handicap up there?
Cheers, George (1991 Hunter 35.5 - PROMETHEUS)
Hi George, congrats on your racing successes. I guess you've learned this boat can fly when properly set up. I'd be interested in hearing what your various rig settings are. It took me many years and a ton of racing to dial my rig in due to a lack of reliable info availability. In particular I'm curious how much rake you have and what you use for the shroud settings.
BTW I highly recommend loosing the wire backstay in favor of a much lighter stronger rope backstay. As you can see in the pics, I use a flicker to hold the backstay clear of the roach of the main for easier gybing.
BTW I highly recommend loosing the wire backstay in favor of a much lighter stronger rope backstay. As you can see in the pics, I use a flicker to hold the backstay clear of the roach of the main for easier gybing.
Alan, Thanks for the picts, I like your flicker. What rope do you use for your back stay?
George, I have not gotten anything back from RigRight, I had sent them an e-mail a few months ago but I may have had the wrong e-mail address, Alan provided an e-mail and I will inquire about the strut. I will use the picts Alan provided and should be able to scale for some dimensions. Will update if I get a reply fro RR.
Sure, I can send you the VPPs, but the file is 11.5mb, can try to e-mail to you, send me a private message with your e-mail address.
My PHRF is 138. It was my 1st year with the boat and did well. Before the 35.5 I had a C&C30. When many heard I was getting a Hunter some said "so, your going to the dark side" , they all thought my winning streak would end with the new boat.
George, I have not gotten anything back from RigRight, I had sent them an e-mail a few months ago but I may have had the wrong e-mail address, Alan provided an e-mail and I will inquire about the strut. I will use the picts Alan provided and should be able to scale for some dimensions. Will update if I get a reply fro RR.
Sure, I can send you the VPPs, but the file is 11.5mb, can try to e-mail to you, send me a private message with your e-mail address.
My PHRF is 138. It was my 1st year with the boat and did well. Before the 35.5 I had a C&C30. When many heard I was getting a Hunter some said "so, your going to the dark side" , they all thought my winning streak would end with the new boat.
Alan, this won't be of much help to you, because my main is off a Schock 35 and is old, full, and draft forward, so I have to build in about 6-8 in. prebend, but my rake is about 10 in. I don't have a Loos gauge, but my uppers are scary tight. Unfortunately, that all means I have to carry about 8 in. of headstay sag. Runners are out of the question so I want to go with the jumper set up. Or, you could sell me one of your good old dacron mains ;D
Alan, I forgot to mention the backstay. I have the original wire but a specta split adjuster. Was hoping to pull the rig this year, but it was not to be. Love that flicker, my leach is suffering.
Have you tried replacing your spin/main/jib halyard blocks with roller bearing models? I have a hell of a time dousing the chute. Too much friction somewhere.
Have you tried replacing your spin/main/jib halyard blocks with roller bearing models? I have a hell of a time dousing the chute. Too much friction somewhere.
My rig is set up with 17" of rake and 4" prebend. The shroud settings are from top to bottom, 3000, 1400, and 3000. The backstay is completely spectra which saves a huge amount of weight. When I removed the old wire backstay I couldn't believe how heavy it was. With the backstay tensioned I get about 4" of sag on the headstay in 15kts with a #1 up.
The key is to get as much tension in the cap shrouds as possible to control the headstay before the backstay tensioner is applied and to keep the mast from tailing off to leeward. Then the intermediates are tensioned to control prebend.
I have replaced the sheaves on the halyards but only with the stock acetate. I have virtually no friction in the hoist of any sails. My halyards are all 3/8" spectra. The main is easily hoisted by hand (no winch) except for dialing in the correct luff tension.
The key is to get as much tension in the cap shrouds as possible to control the headstay before the backstay tensioner is applied and to keep the mast from tailing off to leeward. Then the intermediates are tensioned to control prebend.
I have replaced the sheaves on the halyards but only with the stock acetate. I have virtually no friction in the hoist of any sails. My halyards are all 3/8" spectra. The main is easily hoisted by hand (no winch) except for dialing in the correct luff tension.
Alan, thanks for the data. I think my tuning would have to differ from yours due to the wing keel and 140 headsail. I carry about 1.5-2 spokes of weather helm in 8-10 kts true. Sound right?
Good point on the halyard, stripped halyard with a 3/8 spectra core would probably eliminate the friction better than new sheeves for my 9/16 halyard.
Great to have some renewed interest in "pimpin' the ride" on this site!:dance:
Good point on the halyard, stripped halyard with a 3/8 spectra core would probably eliminate the friction better than new sheeves for my 9/16 halyard.
Great to have some renewed interest in "pimpin' the ride" on this site!:dance:
Hey Mike, got the VPP's, and thanks a million. Had our first race of the year on Sat. 106 boats started. 1 boat finished. Wind died. 105 boats raced to the bar.
I'll try contacting Rigrite also. Maybe they will think it's a new market opening up!
I'll try contacting Rigrite also. Maybe they will think it's a new market opening up!
I have sandbagged this forum for a couple of years, but now I have to ask a question. This Jumper Strut looks like it could solve my headstay sag problem on my Hunter 30-2. The 30-2 came out out of the same series of boats as the the 35.5 and the rigs look very similar. Was the Jumper Strut an option, or something you (Alan) came up with to tame the headstay sag?
John
John
Re: sandbagging
Not quite sure what you mean by sandbagging here?
The jumper strut was never an option available from Hunter. That said, they did build 10 Legend 35.5's in 92 which were used for match racing in Bermuda at the Omega Cup. Those boats had jumper struts added to their masts. When I bought my boat in 93 I ordered a strut from Isomat.
Headstay sag is something that needs to be controlled. On a masthead rig the backstay adjuster can easily do that job. However, on a frac rig the backstay adjuster is completely ineffective at controlling sag by itself. On a frac rig the backstay adjuster bends the mast to flatten the main but does very little to control headstay sag. Adding a jumper strut effectively makes the frac rig a masthead. By adjusting the backstay with a jumper strut installed you gain the benefit of flattening the main and reducing headstay sag at the same time. The only alternative to this is running backstays.
More than a few skippers have expressed an interest in having a jumper strut added for their fractional rigged boats. I definitely would recommend anyone with a frac rig consider adding one.
Not quite sure what you mean by sandbagging here?
The jumper strut was never an option available from Hunter. That said, they did build 10 Legend 35.5's in 92 which were used for match racing in Bermuda at the Omega Cup. Those boats had jumper struts added to their masts. When I bought my boat in 93 I ordered a strut from Isomat.
Headstay sag is something that needs to be controlled. On a masthead rig the backstay adjuster can easily do that job. However, on a frac rig the backstay adjuster is completely ineffective at controlling sag by itself. On a frac rig the backstay adjuster bends the mast to flatten the main but does very little to control headstay sag. Adding a jumper strut effectively makes the frac rig a masthead. By adjusting the backstay with a jumper strut installed you gain the benefit of flattening the main and reducing headstay sag at the same time. The only alternative to this is running backstays.
More than a few skippers have expressed an interest in having a jumper strut added for their fractional rigged boats. I definitely would recommend anyone with a frac rig consider adding one.
Hi Alan, I have contacted Rig-Rite, and they are still singing the same song. They want pictures (pesumably close-ups), all the dimensions, and sketches for the jumper assembly.
Seems to me that I could have this made up locally with just the dimensions. It looks like the mast taper does not affect the pattern, and I can make a template at deck level which will fit just fine. It appears that the arms are at 90 degrees. Only other info needed would be:
-type and size of shroud attachment points.
-wire size.
-configuration of spreader tips.
I can't tell from the pics, but do you think the spreaders were made from the standard Isomat spreader stock?
I know it's a lousy time of year to be mast climbing, but I would be happy to underwrite an expedition by an eager, young prospective crew member w/tape measure and camera to bring back the pertinent data!
BTW, are you happy with the placement of the lower shroud attachment points, or do you think they should be lower and closer to the headstay termination?
Let me know what you think, and thanks again for all your help.
Seems to me that I could have this made up locally with just the dimensions. It looks like the mast taper does not affect the pattern, and I can make a template at deck level which will fit just fine. It appears that the arms are at 90 degrees. Only other info needed would be:
-type and size of shroud attachment points.
-wire size.
-configuration of spreader tips.
I can't tell from the pics, but do you think the spreaders were made from the standard Isomat spreader stock?
I know it's a lousy time of year to be mast climbing, but I would be happy to underwrite an expedition by an eager, young prospective crew member w/tape measure and camera to bring back the pertinent data!
BTW, are you happy with the placement of the lower shroud attachment points, or do you think they should be lower and closer to the headstay termination?
Let me know what you think, and thanks again for all your help.
Whoops,
Re: Jumper stays lower attachment points. I meant to say "lower and closer to the termination of the intermediates at the second set of spreaders."
Re: Jumper stays lower attachment points. I meant to say "lower and closer to the termination of the intermediates at the second set of spreaders."
Hi Mike, looking at your picture, it appears that you can carry your headsail with the chute without much problem. What size headsail are you running and what is the apparent wind angle range that you find it effective?
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