Bieker rudder on a J/111?

Roleur

Super Anarchist
2,881
560
Orcas Island
Heard it's been done.  Recon is now sporting one.  Anyone know anything about it?  

We've been discussing a rudder upgrade.  4 of the 6 boats in our region have already replaced their rudders.  I believe 3 of them still have the same blade configuration.  

Having raced our J/111 for a year now, I can see the appeal of a different blade shape.  

FWIW, looks like it was a 3 sec/mile hit in PHRF.  

 
First post yay!

Here is my understanding of the rudder changes from talking briefly with someone close to the situation:

1: the rudder post and bearing were substantially under designed and break chronically across most j/111. J boats offers an upgraded bearing/post package that fits in the old profile increasing its diameter from ~80mm to ~82.  The boat owner wants to potentially race off shore and wanted a much stronger setup. The new PB designed rudder is ~100mm.

I have heard of similar poor quality in foil shape on j/boat keel fairing/alignment in other of their production boats, so this seems reasonable.

2: the stock j/111 rudder profile was pretty underwhelming with the maximum camber at around 50% of chord length. This has been brought more inline with a NACA section around 30%. I don’t know the specifics of how much the chord/camber ratios have also been adjusted. But as PB is a foil and hydrodynamic expert, quite possibly a lot. I do know the foil’s overall taper was changed.

3: the Stock rudder is also being retrofitted to work with the new bearing setup  to revert it to the one design blade. not sure if the setup would still qualify in one design, but as it would be the original blade, just a essentially reinforced bearing and post, I would guess it would probably be allowed?

 

sinker

Member
62
3
only a little different 
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ZeeZee

Member
177
12
Before doing such an upgrade I would ask for underpinning VPP (or other sound) numbers.

Likely such upgrade are like in high end audio:  many times it's just snake oil sold by a sleek marketing story while in reality there is zero difference. And if many other cases such "upgrades" make the product to perform even worse.  But as the owner paid a lot of money for it he will of course report that the upgrade is substantial and that he is very happy with it.

So therefore: ask for some objective proof that it is indeed an improvement.

 

Snowden

Super Anarchist
1,034
521
UK
for real boatyard bragging rights you need one of these Bieker rudders:

RudderTubercles.jpg


 
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hrothgar

Super Anarchist
4,277
153
Ada, MI
really kills much chance of a local one design fleet forming. Does this design really improve much of the boats controllability/performance offshore? 
I guess if you have no aspirations of sailing one-design, that would be OK.  Unless you keep both rudders and swap them out.  Seems like overkill to me.

Hroth

 

ryley

Super Anarchist
5,429
621
Boston, MA
Before doing such an upgrade I would ask for underpinning VPP (or other sound) numbers.

Likely such upgrade are like in high end audio:  many times it's just snake oil sold by a sleek marketing story while in reality there is zero difference. And if many other cases such "upgrades" make the product to perform even worse.  But as the owner paid a lot of money for it he will of course report that the upgrade is substantial and that he is very happy with it.

So therefore: ask for some objective proof that it is indeed an improvement.
go back and research how many 111's have lost their rudders offshore, and you'll quickly come to the conclusion that any rudder is an improvement over the original design, even if its just the post/bearings that are upgraded.

 

neuronz

Anarchist
879
74
europe
only a little different 
Areas seem to be similar. Most obvious difference is a higher aspect ratio which also increases the bending moment and thus requires strengthening the post. The balance has been changed as well with the post positioned further aft. An interesting feature is the slight sweep of the tip.

 
The foil section also appears to be much narrower making it less draggy, however generating less lift at higher angles of attack.  

Almost looks like the profile 63-009 compared to 65-021.

~1/3 reduction of drag based on the graph and not a large impact on lift until extreme AOA.

it sounds like the post would have needed to be increased substantially even on the old shape, as they were under sized.  
 

the balance and placement of the post is also an interesting change to point out. As the aspect ratio of a foil increases, the distance from the leading edge to the venture of pressure also increases. Moving the post back adjusts for this, keeping the post more in line with the center of pressure and thus balanced. 

Also interesting is that it appears camber max is moving forward on chord length as deeper on the foil. I would hazard here that the sweep and camber reduction further reduce the generation of tip vortices and their drag effectively further improving aspect ratio and drag reduction.

(Images below are from principles of yacht design)

FF1184F6-D145-4F1E-A04C-FB70956288E3.jpeg

F1A269EA-021B-4A1D-8654-333591C2B37E.jpeg

AACF4242-0C79-4A2D-B253-A8C627883A18.jpeg

 

Roleur

Super Anarchist
2,881
560
Orcas Island
really kills much chance of a local one design fleet forming. Does this design really improve much of the boats controllability/performance offshore? 
We have 7 J/111's in the PNW.  Only the latest arrival has OD sails.  Everyone else has larger mains and spins, possibly larger jibs too.  OD isn't happening around here.  We can have some great fleet racing though, but at present the boats rate from 39 to 48.  I expect the 48 will go to 45 soonish.  We'll have 5 111's on the line next week for the first time in the PNW.  That should be very good fun.

Our new rudder is on order.  Hoping to stick in in January.

 
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