Jumper Strut 35.5

[Alan]

George,

You are correct about fitting a curved section to the bottom of the mast. The taper does not occur until it clears the base of the strut.
The location of the lower strut cables is set below the hounds. This effectively makes the top section of the mast a lever for the backstay and transfers the load at a point below the headstay. Therefore, provided the lower shrouds are sufficiently taught moving them further down would not accomplish anything.

I like the way you think, however. This is the kind of critical thinking that is needed to make intelligent choices.

 

[George8396]

Mike and any other 35.5 guys: I have located original drawings of 35.5 jumper set up and will have a quote on making these up soon. Please copy this to all owners that may be interested in this great performance enhancement, as we will only have one shot at getting price breaks for a multiple unit order.
Stay tuned for more info soon.

 

[Alan]

Hey George, that's terrific news. Would you mind posting the drawings? I would love to have a copy for my files. Next trip up my mast I will take Loos readings of the stays.

To any skipper who is considering the merits of a jumper strut, I strongly advise you get one for your boat if you care at all about sail trim, it makes a world of difference.

 

[George8396]

Thanks Alan. I have just located the drawings. The manufacturer probably won't want to share them with us until after they get an order, if at all, but I'll ask anyway. Hope we get some interest on this.

 

[MikeL]

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?

George in that pict the apparent wind angle may have been around 135 degrees. The wind was light and variable that day but after I pulled the chute up the headsail appeared to still hold a good shape so I did keep it rolled out for most of the leg, I am not sure how effective the combination is. My head sail a about a 155 tri-radial mylar showing some age. I did finish with line honors and 1st place in that race.

 

[George8396]

MikeL and any other interested owners: I have finally gotten the quote on jumper strut from Sparcraft. This is for the strut itself only, and includes spreader end caps, all anodized. You can do the wire and toggles locally. $600. for 1-3 orders, $500. for more.
Spread the word to any owners you know. We need at least 2 more for the discount. Let me know who is in and I will coordinate.
Cheers, George

 

[Alan]

The price sounds quite reasonable but I would suggest posting on the "Ask a Hunter Owner" forum. It will get a much larger viewing audience. Seems few Hunter owners venture into the dreaded racing forum. Keep in mind that this strut would benefit almost any frac rig boat.

 

[MikeL]

George the price does seem reasonable. As you noted Sparcraft has the original 35.5 drawings, therefore I would expect the drawings to show detail like the complete installation or assembly design. I can see from Alan's picts of his strut of the installation but more details would be helpful like angles of wire, tang detail, and strut fastener detail. George would an order be just the strut in a box or would it also include some installation details. Either way I would still order one. Better yet I think I would pay more for the whole assembly if available. Alan, when you purchased yours from Isomat, do you recall if you received the strut only? Or was it a like a complete kit?

 

[Halipeño]

I just ran into your posts and I'm interested on the Jumper Strout. I have a 1995 35.5 and do some beer can racing, but always looking to increase the performance of the boat.
Do you have to unstep the mast to install it or can you do it while the mast is up?
How is it attached to the mast?
Do you have to thread the holes in the mast for the bolts and if so, is it stong enough?
Do the bolts go thru to the other side?

Oz

 

[Halipeño]

Mike,
What are VPP's
Oz

 

[George8396]

Hi Oz, You don't have to unstep the mast to install the jumper, but it would be easier. The strut attachment bolts would be threaded into the mast. The jumper stays (my guess) would be thru bolted with tangs for wire terminations to attach to.
We will learn more soon, as Alan has all the info on these and will probably set me straight.
What say you, Maestro?

 

[Alan]

I did some digging back into old paper work to find the original invoice for my strut. It cost me $312.50 for the complete strut (1/31/94). Seems like a bargain now!
The base of the strut is attached to the mast with tapped screws (not through bolted). The shrouds for the strut are T ball attachment just like the other shrouds. Through bolting is a viable option also. The bottom of the shrouds have turnbuckles for tension adjustment.

Oz, VPP's are Velocity Prediction Program. They give you the 'sail to' numbers for any wind speed and sail configuration. These target boat speeds are the ideal readings under ideal conditions. The strut is going to give you much better sail shape and better pointing than you now have. The result will be better boat speed while sailing higher.

 

[Halipeño]

George and Alan
How are the T ball attachments attached to the mast?
Will you post the drawings.
Oz

 

[Alan]

Ooops!...

My mistake , after closer inspection of my rig the shrouds are attached with stem ball fittings. You can see them in the link:
http://www.rigrite.com/Spars/SparParts/Tangs-complete/Tangs-complete.htm
It is very similar to T ball and can be done without taking your mast down.

If you take a close look at the cap shroud and strut shrouds you will see the stem ball fittings. The red arrow is where I placed the new masthead spinnaker halyard sheave for my big A-kite.

 

[Relentless]

Re: Ooops!...

Hey Alan, just wondering about your rating with all the mods, phrfLI shows a base at 144, down here in S Florida those mods would put you around 129-132. What kind of hit do you take for a sprit,masthead kite,jumper strut,spectra backstay

 

[Alan]

Relentless

My fin keel cost me 6 seconds, the jumper strut no change, spectra backstay no change and the sprit 12 seconds. That puts us at 126 and we are still extremely competitive at that. Well worth the penalty I can assure you. I regularly beat boats that rate 110 to 120.

Most of the racing I do now is on a Soverel 33 and much of that is one design. When we race PHRF she rates 90.

 

[Relentless]

Re: Relentless

Sounds like you have a top notch program withl steady crew. The crew is my biggest problem, there are so many serious programs down here that good crew is hard to find. That and the fact that I can't fund a proper campaign. We do have fun with the more casual racing and have won our share of pickle dishes.

 

[MikeL]

Gerorge,

Wondering if you have heard back from Sparcraft. The off season is coming to an end.:dance: Were there any other interested skippers for a strut?

 

[MikeL]

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.

Alan, are you sure if the mast is a NG51? I think the mast is a NG-46.

Sparcraft is building one for me and will be happy to build more. The contact is Dave Lively, he can be reached at DLively@sparcraft-us.com, or at 704-597-1502.

 

[Alan]

Mike, I'm not putting money on it but I'm fairly certain its an NG-51. That's how I have it listed in my files. To be certain you can check the measurements of the section, the NG-51 has a long axis of 7.48" whereas the NG-46 is 7.09"
How much are they charging for the strut? Most Hunter owners could use the strut but just don't realize the significance of it.