Asym Spinaker-Sprit and RRS - SailNet Community
LinkBack Thread Tools
post #1 of 7 Old 03-25-2002 Thread Starter
Junior Member
Join Date: May 2001
Posts: 22
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Asym Spinaker-Sprit and RRS

Here ya'' go guys..Looking for some input on this one. I''m trying to get more performance out of an asym. This should get some real comments:

I think I figured out a way for a sprit for my asym spin. OK, it is permitted to pole out an asym spinnaker.

The normal method is from mast mounting to the clew. The asym normally has a tack line which runs through a turning block mounted forward of the forestay on the bow then it runs back and is secured to the cleat on the foredeck.In this configuration the tack of the asym is about 4 foot above the deck and only inches forward of the forestay.
My change, which I think would not violate any rules; is that I would take my whisker
pole and mount it on the normal mast fitting but let it drop down to the bow pulpit and secure it with a "fixed downhaul". Then mount the turning block in the forward jaw and lead the tack line through the turning block back to the foredeck cleat.

The advantage to this arrangement is that by extending the turning block 3-4 feet ahead of the boat is will let the asym to a better job of ''pulling'' the boat.
I looked through the rules and I think this might fly...
capedorian is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
post #2 of 7 Old 03-25-2002
Senior Member
RichH's Avatar
Join Date: Jul 2000
Location: Pennsylvania
Posts: 3,689
Thanks: 26
Thanked 177 Times in 166 Posts
Rep Power: 17
Asym Spinaker-Sprit and RRS

What kind of boat and are you racing PHRF, one-design, etc.?
What kind of Whisker pole? rigid or adjustable?
Anything that you can do to open the distance from the mast to the spinnaker tack will be of benefit - downwind.

However, there are some structural concerns that I offer: Is your pulpit going to take the strain ?.... probably not in most cases as they are usually not set to the deck with vertical loads (large backing plates and stress connections to bulkheads, etc.) in mind. Secondly, will the pole be strong enough as you will be essentially constraining the pole at midspan rather than from the ends - different stress considerations as whisker poles and spinnaker poles are designed for typically tension along the axis of the pole - not designed constraining or loading it from the middle.
For light winds ...... probably not a risk with anything you try.... but if the wind gets up and A-Kite starts to really lift the bow .... you can easily break/bend a constrained pole and possibly pull the pulpit free. For a boat with a strong waterline bow eye you might consider to attach a restraint from the eye to the outboard end of the pole etc. to take the strain instead of the pulpit.
RichH is offline  
Quote Quick Reply Share with Facebook
post #3 of 7 Old 03-26-2002 Thread Starter
Junior Member
Join Date: May 2001
Posts: 22
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Asym Spinaker-Sprit and RRS

Aside from structural issues. Is it or could it be construed to be within the racing rules of sailing for a PHRF boat?
capedorian is offline  
Quote Quick Reply Share with Facebook
post #4 of 7 Old 07-25-2002
Join Date: Jul 2002
Posts: 68
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 14
Asym Spinaker-Sprit and RRS

I believe that according to PHRF rules you arn''t allowed to tack the sail beyond your rated "J" dimension without a rating penalty. I have researched it a bit and have found out you can extend on a retrofit up to 25% of of "J" with a 3 second/mile penalty on the Chesapeake Bay at least. I am considering going to an asy spin for my O''Day 30 as its getting to be a real hassel to get a crew of 6 to go racing competatively.
Have you found any numbers on how much faster off the wind a boat is using a sprit vs tacking it at the stem of the bow?
Last weekend on our way home from the Solomons race we played around a bit tacking our downwind genoa to a whisker pole that was fastened to the deck and to the headstay fitting and extended about 4'' in front of bow. It seemed to be faster with app wind in the 90 to 120 deg range but did not actually get comparsion numbers.
I would be interested in any info you have found.
capnjim02 is offline  
Quote Quick Reply Share with Facebook
post #5 of 7 Old 07-25-2002
Jeff_H's Avatar
Join Date: Feb 2000
Location: Annapolis, Md
Posts: 7,039
Thanks: 5
Thanked 176 Times in 143 Posts
Rep Power: 10
Asym Spinaker-Sprit and RRS

My sense from sailing on and against assymetrical spinackers is that unless you are sailing a very light weight easily driven boat that can really make big gains by sailing hot angles and scalloping down in gusts, your VMG will actually drop with an assymetrical spinacker vs a symetrical chute. So you are taking a 3 sec a mile hit for a sail that may be costing you more than than in downwind VMG.

Jeff_H is offline  
Quote Quick Reply Share with Facebook
post #6 of 7 Old 07-30-2002
Senior Member
Join Date: Nov 2000
Posts: 111
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 16
Asym Spinaker-Sprit and RRS

My sailmaker has tried an interesting experiment on his Beneteau First 40.7.

He put a sprit on it, and races with an asymetrical. He does not use any symmetrical spinnkakers. The local PHRF ruled it a wash - the sprit & assym was cancelled out by the loss of VMG downwind. So he rates the same as my plain vanilla 40.7.

He''s won a few races so far but also lost some, it''s hard to tell exactly what the impact is still.

I expect to be racing against him next month, should be interesting. Eliminating the fact that he''s about 100x the sailor and driver I am, it should be interesting to see how the two boats compare.
bporter is offline  
Quote Quick Reply Share with Facebook
post #7 of 7 Old 01-03-2003
Junior Member
Join Date: Apr 2001
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Asym Spinaker-Sprit and RRS

We have an Evelyn 32-2 and is a light and pretty fast boat (PHRF 96). But our problem is that we always sail shorthanded (normally 4 and 2 over 60 years old). We have always sailed nonspinnaker have have been very successful in the fleet. So this year we want to go spinnaker and knew that if we did so, the decision would be to use use only an Akite. To facilitate this we have used a roller furling for our 155 and a snuffer for the Akite.

Whether we use a bowsprit in still being decided and we are testing out the cost of using a bowsprit over the permitted length. We think that the bowsprit is a necessity and plan on using the length that will give us the best advantage per penalty for length. Equally important is the your rules permitting the sprit to be articulated and by how many degrees. This would provide some fantastic speed improvement but you would have to make the sprit so it can be articulated on either side of course. We are also concerned as to the mounting of the sprit and I also agree that you should take a very, very conservative approach and anchor it the strongest way possible. The pulpit would be the last choice for us. Go for the waterline eye and make it strong as you can. The leverage that sprit will have that far out will mean some big pressures. If you err, built it too strong.

Good luck. Let me know how you do.
GeneHale is offline  
Quote Quick Reply Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome