Hobie Cat Forums

It is currently Thu Jul 31, 2014 4:50 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: Rudders up under sail?
PostPosted: Mon Aug 26, 2013 5:11 am 
Offline
Site Rank - Captain

Joined: Tue Apr 08, 2008 8:54 am
Posts: 26
Hi,

I was looking at this picture, admiring their extreme mast rake, when I noticed that their rudder(s) is/are up!

Image

I initially thought it was some sort of fluke, but then I saw the same thing in another photo a few minutes later:

Image

Their rudders (or at least the windward rudder) appear to be in the UP position while under sail. My H16 is an `81, and judging how brassed off the finish is on the cross bar, the tiller mechanism is probably original, so maybe something has changed, but I struggle to envision how you would do this while under sail. (Not to mention that I've had enough trouble with H16 rudder cams over the years that I would be hesitant to tempt fate by locking and unlocking them frequently.)

Can someone explain what's going on? Are they unlocking just the windward rudder? How does that work with the tiller? On mine, when the rudders are in the up position, the tiller crossbar sits several inches below the main rear crossbar, and having the tiller extension going up over that main rear crossbar causes the rudders to come out of the "locked up" position. I guess in both pictures the helmsmen are out on the wire, and in the second pic, you can see that he's holding the stick such that it's not touching the main rear crossbar, even bought the tiller crossbar (such that we can see it in this photo) is sitting below the main rear crossbar.

I guess I can see the motivation -- less drag is less drag -- but what are the practical mechanics of this?

Thanks,
Ian


Top
 Profile  
 
PostPosted: Mon Aug 26, 2013 6:23 am 
Offline
Hobie Approved Guru

Joined: Mon Jul 14, 2003 7:11 pm
Posts: 4580
Location: Detroit, MI
While your '81 and these ~2008/2010 boats are both Hobie 16s and are superficially identical, there are several design changes in the rudder system since the '80s that cumulatively make a huge difference in performance.

The rudder kick-up system on newer boats just works. Rudder goes down smoothly, 'click' - it's locked down - and if it's very new, there will be virtually no slop in the entire system. Quick jerk up and forward and cam releases, the rudder comes up, and stays parked in the up position. It just works. It's hard to explain to someone who's struggled with their rudders on an old boat how well the system works when it's been adjusted properly.

As for the technique in the photos - only the windward rudder is up, and yes - the lockdown system works so well that they change on every tack. The top (younger) skippers are proficient enough to pop the rudder up with their rear foot while on the trapeze.

As to why they do it - there are two reasons 1) it forces you to foot going upwind. In heavier air, the Hobie 16 makes better VMG to weather when you foot rather than point, which requires more rudder movement. With only one rudder in the water, you'll stall out if you try to point. 2) in heavier air, the part of the windward rudder in the water is very draggy, so you put the rudder up to get rid of the drag.

This is a very advanced and somewhat difficult upwind technique to master (the first photo is of 2007 world champions Mick Butler and Susan Etherington). You'll only see the very top of the fleet at a major championship use it.


Last edited by MBounds on Tue Aug 27, 2013 4:40 am, edited 1 time in total.

Top
 Profile  
 
PostPosted: Mon Aug 26, 2013 10:52 pm 
Offline
Site Rank - Admiral

Joined: Sat Nov 26, 2011 11:35 am
Posts: 152
I've done this a couple times on my '80 H16.... Kinda just happened naturally when i was screaming along in heavy air..... Both times the leeward rudder snapped in half within about 10 mins. The OEM older plastic rudders cant take the strain or weight, however it was some fun fast easy steering while it lasted! Got a 90's EPO full setup with the adjustable castings now... just need to put them on.

Tim

_________________
Tim Grover

Memphis, TN

1978 H16 (sold)
1986 H16 (sold)
1980 H16 (sold)
1996 H20 Miracle (just right)
Bought another H16. Solid!!


Top
 Profile  
 
PostPosted: Tue Aug 27, 2013 6:33 am 
Offline
Site Rank - Captain

Joined: Tue Apr 08, 2008 8:54 am
Posts: 26
I was out yesterday and gave this a try. It made a HUGE difference. So much of a difference in fact, that I beached the boat to check the rudders, and discovered a HUGE unintentional toe-in (I'm guessing my crossbar adjustment got banged in somehow). After re-trimming the rudders (such that I could with what tools I had on me) the boat was moving MUCH better in general. Kicking up the rudder still made a difference, but far less of a difference, and seemingly only if the hull was totally out. Thanks for this teachable moment, folks!

Next project: tightening up the rest of the rudder/tiller system, and adjusting the rake to get rid of (some of) this weather helm.

Ian


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group