Larger Wider Turbo Fins

Hey Ya'll
I would like to try and use an even bigger Turbo Fin to see if it would add more speed or power. I think my drumsticks could handle at least 15 to 20 percent more size than the current turbo fins offer.
Any plans on the table out there for an "El Grande Turbo" and a heavy duty sprocket ?
Kepnutz

No plans for a bigger fin, but strainless sprockets should be available again starting next week.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Hey Matt
Do you have your part number handy for the strainless steel sprockets. I tried to get price and avail last week from my L.B.S. on the Turbo Fin repair kit you suggested but have not heard back from them yet on that one.
Why not try to make the new sprockets out of agonized aluminum like 7075 using billet stock on the CNC. It might be lighter than strainless and stronger than the composite..? Just curious..any who can you please send me a couple strainless sprockets and a turbo fin repair kit..
...............Thank You
.................................Kepnutz........................

I would much rather have strainless than agonized aluminum. In fact, if possible, I would get a completely strainless derive.

Hi ya Roadie...
I would think that an all strainless drive would weigh about 1.5 trillion pounds and may exceed the max weight limit of my boat..
I still have a bundle of top shelf, high quality, bicycle components made from aluminum stock that I have used for many years that still work : hubs..wheels...brakes...bars...chainrings...pedals..seatposts..headsets and frames so why not use aluminum to make mirage drive material ?
Its light and strong and does not rust etc..etc ?
How's your repaired thigh knuckle doing..? Are you back out on the water using the pedals in that new AI..?
....Have fun out there...take it easy

-Kepnutz-

Hi Kep,

Here's a great project for you and a good way to get rid of some of those old bicycle parts:



Regarding enlarging your fins, you can make a set of ETs (Extended Turbos) that look like the left set, below:



The only problem is this mod would likely void your Drive warranty because of the extra stress on the parts. I'm using an older drive here (out of warranty) with strainless sprockets.

These will give you a better workout, but with your Tandem, you've already hit the wall in terms of max speed! If you seriously want to try this, you'll need to make a couple of parts. I can e-mail you with the details.

Stainless sprockets are shown in the new catalog in the parts diagrams under "Parts for older drives"

Stainless sprocket 81130001 $30.00
Bushing 81340001 $8.95
Sprocket Guard 81420001 $6.95 (shown as DSQ but on the shelf)

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Thanks Matt.. Thanks Roadmaster
I was curious if the stainless sprockets will work with the new mirage drive spine thingy. The older drive pictured on the left in Roadies post above, looks much more open than the newer version on the right, are you sure they will be compatible? Also would I need to oder the sprocket guard and bushing as well..? As for a bigger turbo fin I was thinking a tick wider but if wider and longer dont mean any faster per say then why mess with it just to break more parts..etc..etc
As far as mods go has anyone made a bigger rudder for sailing using the drop down style that will add more control in heavier winds. Maybe the winglet might help but what about "larger" size wise..rudder mods..?
Kepnutz

I'm still testing this arrangement out -- not sold on it yet. I'll get back to you within a couple of weeks with a recommendation.

Here's a post on modifying the older style rudder:
http://kfs.infopop.cc/eve/forums/a/tpc/ ... 9941060883

Hey Roadie
Thanks for the lead on the rudder mod over on KFS. Im not so sure about that one either. I would prefer some other material be used rather than formica. That stuff just does not seem strong enough unless glued onto a countertop, I do like the idea of a sleeve fitting over the rudder like a hand in a glove and not having to take the rudder off. I was also considering making something using fiberglass cloth and then glassing it on over the old one in strips like a surfboard fin. Lots of sanding and finishing of the new shape which would require a few more hours of work plus removing the rudder as well to make it all possible. Perhaps I shall look for some sheets of 1/8" black nylon/plastic/teflon material cut it , glue it and then add a few stainless rivets to seal the deal etc. The only thing left is to determine the size..how much bigger wider longer and shape etc.. Well if I do come up with a workable, tested something something I'll take some of step by step pictures and post'er up on the site
-------------Kepnutz--------------

Hey guys,
Wow—Hobie leads the way again with “strainlessâ€

_________________

Hi Dick,

By gosh, I must have got the other part of your order! I'd say we have a pair of "tweeners"! Mine would rate a mixed review; how about yours?


I much prefer the strainless, because of its simplicity and ease. Unlike what Kep said, I don't it would be heavy at all. On the other hand, agonized, though light, would probably break under the slightest stress!

Kep, regarding your rudder size --

General guideline -- about 20 to 25% of the rudder should be forward of the turn axis so it doesn't feel "heavy" or unbalanced under load.

Long and slender (higher aspect ratio) is more efficient to short and fat.

A little goes a long way. Don't add more than you need. About 50 to 60 % larger surface area including a couple of inches in depth should give you a nice improvement.

Before breaking out the fiberglass and re-shaping, you might try a winglet on the existing rudder. Much simpler to do, it may give you enough improvement.

Hey Ya Roadie... Hey Latch Patch Kid..
Thanks for all the rudder info , I will sort all this stuff out before I make any moves. Today I was out at our local water hole and felt the rudder stall several times. We did beat a Hobie16 upwind because we could pedal through the tacks and flat spots..but if the wind was really strong they would have killed us for sure.. Perhaps your wing tips will do the trick though on my rudder.
SSShhh....... be verwee verwee kwiet..Im hunting wingwets..huhuuhuh
Thanks again
Kepnutz