Hobie 18 with comp tip, where do i put the spin halyard block on the mast, how high up and is it o.k. to put it on the comp tip section? thanks

The usual advice is 1/3 of the way above where the shrouds attach... but with the comptip.... I am not sure. Can you attach stuff to the comptip without it exploding?

Mitch:

Be careful. I was going to put a Hooter on my 17, but they told me it would break mast. Try to find a 18 SX to look at. Don't they have a spin?

Doug

I looked at the parts diagram on Hobiecat.com, it's not obvious. I was hoping to see an 18SX-specific mast or comptip, but no dice.

Per the class rules (hobieclass.com), Hobie 18SX Rule 14 b): "The [spinnaker] sail cannot be attached to the mast above 23 ft. 11-1/2 in. (7.30 meters) measured from the bottom of the mast extrusion."

I believe that the only difference between an 18 mast and an 18SX mast is the comptip (the 18SX is longer). Matt Miller or the guys at Surf City might chime in here, but I'm very certain that there was an upgrade kit at one time to upgrade a standard 18 to an 18SX, and it included the wings, sails, rigging, and longer comptip.

If this is true, measure your current 18 mast, find the place where 23 ft. 11-1/2 in from the bottom puts you, and maybe go a little lower. I'm fairly sure they are rigged from the comptip.

Hope this helps.

Mike

Mitch:

Do you already have the spin, pole and hardware?

http://www.thebeachcats.com/classifieds/showproduct.php/product/463/cat/4

Doug

The comptip is the same. The SX mast is longer due to cutting the extrusion longer (I think 9 inches, but could be rong about the actual number).

This is not true. This was the advice that the designer of the Supercat line, Bill Roberts, gave to everyone. However nearly as goood as all other designers (and therefor designs) have the spi gate at 60% of the distance between hound fitting and mast top.

In effect: It your mast is 8.5 mtr long and your hound fitting is at 6.0 mtr. then the spi gate will be at (8.5-6.0)*0.6 + 6.0 = 7.5 mtr.

This distance is also used on the F18's, F20's (inter-20) and the F16's to name but a few well know cat types with a spinnaker.

Wouter

It is OK to put in on the comptip. Follow the Hobie installation advice - which gives a postion about 1/3 the way up the comp tip. Higher than that and you are really overstressing it without the addition of mast heads shrouds to stabilise the comptip.

Don't cut your pole as short as Hobie suggests - this results in a very narrow slot between the spinnaker and jib. Go about 11' long. You will have to mount the spin blocks somewhere between the rear cross beam and the side shrouds to get the correct sheeting angle (assuming you have the Hobie factory kite). Make up some stainless slugs to fit under the lip and through bolt into them to distribute the load. Not class legal - but who cares unless you'll be in a fleet of class legal H18s with spinnakers.

Good luck with your project!



Hobie 18/18SX parts manual shows different part numbers for the mast extrusions (the 18SX is 18" longer but the same section as the stock 18 mast). The comp tip is the same part number for both boats. I've owned both boats and can confirm they use the same comptip. To upgrade an 18 to an 18SX takes a new mast section, rigging, sails.

Chris.

Thanks for clarifying this Chris.

I just re-looked at the Hobie site. There are two links to Hobie 18 parts diagrams, and they lead to different pictures and parts lists...

The one you linked to makes a little more sense than the other one that I found: http://www.hobiecat.com/support/tech/h18parts.html I still don't see two masts listed in this diagram.

I am really surprised that they made the upgrade require a new aluminum section (as opposed to a different comptip). I guess I had bad local knowledge. (Someone in our fleet was considering this upgrade years ago.)

Is the aluminum cheaper than the comptip? It sounds like a lot more work if you have to transfer all the fittings, spreaders, etc. to new aluminum mast AND deal with the comptip, as opposed to just changing the comptip.

Not that any of this answers the original question...

Mike

It depends on the size of your spinnaker, mainly the luff. Remember there is no standard sail for the Hobie 18SE
When I bought a hobie 18 spinnaker from smyth I put the tang 2.5 feet above the hounds per Randy's reccomendation. I also ran with about 2 ft of pole prebend. I'm not sure what the luff was on the spin though.
I ran it of a comp tip for a while no problems until I found a solid aluminum mast.
I'd just make sure you get a tang with at least 4 rivets and rivet it well. I'm not sure the newer style halyard bails would work as the mast track isn't too strong. I just had a regular tang with block off it.

I agree - I'm sure it would not work. The upper part of the 18 mast track is a plastic extrusion that snaps onto the back of the comptip. If you tried to tie a bail line through it it would snap.

I also just riveted a stainless tang to the mast and hung a block from it.

Chris.

>>>I am really surprised that they made the upgrade require a new aluminum section (as opposed to a different comptip). I guess I had bad local knowledge. (Someone in our fleet was considering this upgrade years ago.) Is the aluminum cheaper than the comptip? It sounds like a lot more work if you have to transfer all the fittings, spreaders, etc. to new aluminum mast AND deal with the comptip, as opposed to just changing the comptip.<<<

It is cheaper and less work for Hobie to simply cut a slightly longer aluminum extrusion. For Hobie to manufacture a comptip exclusively for the SX18 would be quite expensive considering the number of SX's that were probably sold.

sm