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HELP with centerboard springs and sailing question.
http://www.hobie.com/forums/viewtopic.php?f=45&t=9424
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Author:  McGyver [ Sat May 17, 2008 4:25 pm ]
Post subject:  HELP with centerboard springs and sailing question.

The springs of one of my centerboards broke. The directions say:

"...removing the bolt and nut located at rear of trunk. You can reach these by removing the hatch cover on deck."

How do you do this when you can barely reach with one hand, you cannot see and the nut and bolt are covered with A.T.V. sealant?

Also, when sailing, should one leave the centerboards down all the time or only sailing upwind.

(Sorry for the beginner question, but I'm a beginner when it comes to multihulls.)

Thanks!

Author:  mmiller [ Sun May 18, 2008 5:04 pm ]
Post subject: 

All I can say is good luck on the spring replacement. It is difficult.

Boards can stay down at all times.

Author:  Rockets [ Tue Jun 10, 2008 6:09 pm ]
Post subject: 

Matt I have two questions..

For S&G's I looked inside my hulls, and my SC has a solid bulkhead where the fastening hardware is obviously on the other side. So, how would I ever change my springs if needed? Drill an access hole through the bulkhead?? How were they installed in the Factory?

My other question is if the SC weighs 600#, can you tell me the weight of the cabin? The SE was @ 420# if I remember right with a taller mast and telescopic beams. I'm just trying to figure out where the SC gained all of it's weight. I know the cabin is heavy, but it doesn't weigh 180#.

Thanks

TC

Author:  srm [ Wed Jun 11, 2008 4:27 am ]
Post subject: 

Quote:
The SE was @ 420# if I remember right with a taller mast and telescopic beams.


I'm fairly certain there's no way the 21SE weighed 420lb fully rigged. 420# is the weight of a Hobie 20. It might the weight of the H21 platform only (no rig). I think the H21 weighed closer to 600lb.

sm

Author:  Rockets [ Wed Jun 11, 2008 7:31 am ]
Post subject: 

Go here
http://www.hcana.hobieclass.com/?Page=2183

Author:  mmiller [ Wed Jun 11, 2008 8:49 am ]
Post subject: 

That link shows min platform, min rig and min wings that come up to something like 560 lbs.

The early Sport Cruiser had no access bulit in for spring replacement... an oversight. You need to cut an access in the bulkhead. You can install a port.

Author:  Rockets [ Wed Jun 11, 2008 2:58 pm ]
Post subject: 

Ok Matt, it appears as though I've been misinformed and was led to believe the SE was significantly lighter than the SC. So if I understand this right, the SC and the SE models weigh virtually the same...560# vs. 600#. I know that the SC cabin weighs more than 40#'s so the SC might actually be a little lighter than the SE without it, and fully rigged otherwise...correct?

I guess what I'm having a hard time with is the increase in power gained by the additional 78 sq/ft of sail area in the SE @ 300 vs. the SC @ 222. I've been told and have read that the SE was fast as hell and hard to keep down when sailing solo. Not to sound dumb, but does having another 78 sq/ft of sail really make that much difference? Or was there another significant design factor at work? I know the sail size wasn't the only difference between the two, but I'm just trying to get a better understanding of the power to weight ratio at the moment.

THANKS for the help and education!

Author:  Beachboy [ Mon Jun 16, 2008 7:54 am ]
Post subject: 

The 21SE is really a very different boat, especially considering the crossbeams telescope out to a 9'9" beam vs. the 8'6" on the SC and the mast is some 6' or so taller. The hulls are identical from what I can tell. They simple reused the hull molds to make a more managable(lower mast) and easier to set up(fixed crossbars) boat but giving up performanace in the process. The cool part is the hulls have lots of flotation so you can load stuff on it for day sailing, like an outboard.
I have my 21SE rigged with an outboard, large hull hatches, and a forward tramp. My latest addition is a roller furling hooter to replace the spinnaker, just finished rigging it, have yet to sail it, but have dry raised, set, and reefed it, so far so good. I"m running it on a "floating" furler on lines and blocks between the two forward hull tangs.

Author:  Beachboy [ Mon Jun 16, 2008 9:01 am ]
Post subject: 

BTW, Spring replacement was not that big of a deal, two people, 20 minutes per side. Do not make the mistake of using anything other than SS springs or they last one season. SS springs are hard to find, you need a good Hobie dealer and they are pricey but woth it.
Also the directions Hobie printed says you have to turn the boat upside down. Not necessary. Just get the hulls high enough to completely drop the boards down and you can easily replace them from the bottom. (If you have hatches like I do) On the 21SE there are two scews on the keel line that hold the board rotating pins in place, they need to come out. The whole trick is to have a couple of sticks about 24" long with the hollow pin and springs glued in place (I used Marine Goop) so you can raise it up into the hull and get the machine screw through from the top and thread the nut on.
I cut 9 1/2" x 13" hatches into my decks just aft of the centerboard bunks so I have access to the top bolts, but I can't actually see them. If you are going to cut holes in the decks I would recommend filling the holes with hatches, you get substantial belowd deck storage, we fitt the newer type folding charis in there with several small coolers, etc. etc. Use the hatches that are designed to be deck hatches, the cheaper access hatches will bow out of shape and leak.

Author:  Rockets [ Mon Jun 16, 2008 6:48 pm ]
Post subject: 

Yeah, I know they are not the same boat, and didn't mean to imply otherwise, but they are similar. The SE has a great reputation, and I'm not looking to trash it either. I'm just trying to compare the performance of the two as best as I can.

Apparently they both weigh nearly the same @600 lbs and have a sail area difference of 88 sq. Ft. The mast is 29 ft on the SC and 33 ft on the SE, but don't know if that's a factor other than you need it to supply the extra sail area. How does the extra wide beam factor in as providing more speed?

So, how much more power does the extra sail area really buy you given the same hulls and weight. In my mind 88 sq. ft isn't that much. Or is it?? Yeah it's an increase of 35%, but as you'll see later that in itself may not be the end of the story.

Just as a comparison, (I'm probably not doing this right...)
if you take the sail area and divide it by the weight for ths SC you'll get a power to weight coeffient of .48. For an SE it's .5 . Compared to an old school SuperCat 17 which had a sail area of 257 sq. ft and weighed 300. so it's coefficient was .85.
So does that mean the Supercat was faster than an SE? I'd like to believe not, but the math makes me wonder. Is there something I'm missing here?

As far as the boards, THANKS for the tips. I don't need to replace mine ...yet. I'm sure the day will come though. I aready have factory deck access, and don't want to cut any new holes in my deck. My problem is looking inside my hull storage area toward the boards, I have a solid bulkhead. Which is why I'm asking ablut the best way to breach it for access.

Thanks

Author:  Beachboy [ Sun Jun 22, 2008 6:05 am ]
Post subject: 

Beam is everything in a cat. Beam replaces the keel counterweight of the monoslug in multihulls. When sailing upwind there is considerable force on the boat trying to tip it over sideways. The larger the beam, the better the levrage in counteracting that force. That's why trapping out is necessary to load the boat fully and get max speed. So yes, beam is critical. That's why you will see the ocean going maxi-cats with 50' plus beams and crazy top speeds. The downside is, where the heck do you moor or dock a boat with 50' beam?
So, the extra 15" of beam on the SE enables it to use the added sail area for more power with no added hydodynamic resistance and minimal added weight = more speed.

Author:  Rockets [ Sun Jun 22, 2008 6:28 am ]
Post subject: 

Got ya.

Thanks

Author:  Team Chums [ Tue Jul 01, 2008 6:23 pm ]
Post subject: 

With the problems I had having to run double springs on each side, I switched to a good, stout bungee that was doubled up. Never any more problems. Not to mention less $$. Easy to get around the pin up top in the trunk and crimp together to attach to the top of the board.

Lee

Author:  Beachboy [ Sun Jul 20, 2008 7:14 am ]
Post subject: 

I like this solution, it will be interesting to see how hmany years you get out of a bungee. Remember, storing the boat with boards all the way down, if possible, will greatly extend bungee, or spring, life. They are at full extension when the boards are retracted.

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