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Turbo Fins Disappointment
http://www.hobie.com/forums/viewtopic.php?f=11&t=3613
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Author:  Windrider [ Wed May 17, 2006 3:24 pm ]
Post subject:  Turbo Fins Disappointment

I just completed installing my new Turbo Fins on one of my two Mirage Drives. The Turbo Fins DO NOT fit the drive properly. There is a large gap between the top of the fin and the drive assembly. The notch in the top of the fin does not align with the chain on the sprocket. The different size of the fin top pushes the aft plastic housing away from the chain and against the frame. Before anyone suggests I made an error in the installation, look at the picture posted by OffRoad on May 3rd under “Tried the new fins on the Adventureâ€

Author:  OffRoad [ Wed May 17, 2006 11:40 pm ]
Post subject: 

Hi Windrider

It’s to my understanding there is to be a gap per design. My new set works fine although the chain slot could have lined up better.

Image

PS Hobie had the sail made by others (supplier).

Author:  Roadrunner [ Wed May 17, 2006 11:54 pm ]
Post subject: 

OffRoad wrote:
My new set works fine although the chain slot could have lined up better.
Ditto

Author:  Windrider [ Thu May 18, 2006 7:53 am ]
Post subject: 

OffRoad,
Great picture, it looks exactly like my drive, thanks for posting it.

Your picture shows how the aft housing has been pushed away from the chain and against the frame. It will rub against the frame with every stroke causing unnecessary friction, resistance, and wear.

I don't believe it was designed with the gap at the top. If that was true, it wouldn't have been necessary to have the chain sprocket notch at all. As it is the notch is useless because it doesn't align with the chain.

Also, on my masts, the notch for the set screw looks like it was filed out by a six year old. It is very crude and misshapen.

It really doesn't matter who made the fins, the name "Hobie" is on them.
The quality of this kit is not up to Hobie standards!

Author:  Klay [ Thu May 18, 2006 11:37 am ]
Post subject:  turbo fins

I got my new fins a couple weeks ago also. I was surprised by the seemingly poor fit. Mine look like those in the picture.

But I'm not too worried by the gap...this is an area of very limited motion on the fin. If there had been some flaw out near the tip of the fin, I would have been dismayed.

It's finally warm enough here so that a capsize is not so life-threatening. I'm taking the boat out Saturday. I've been climbing the walls wanting to go sailing!

Author:  OffRoad [ Thu May 18, 2006 10:09 pm ]
Post subject: 

Winrider try this link.
http://www.hobiecat.com/community/viewtopic.php?t=3499

Author:  Roadrunner [ Thu May 18, 2006 11:57 pm ]
Post subject:  Re: Turbo Fins Disappointment

Windrider wrote:
The notch in the top of the fin does not align with the chain on the sprocket. The different size of the fin top pushes the aft plastic housing away from the chain and against the frame.
First, the notch mismatch should not be an operational problem for you. Looks more like a cosmetic screw-up to me.

Second, you should have clearance between the sproket guard housing and the frame as seen below (click for a better view):
Image
If not, check to make sure you have closed the gap (tightened the mounting screw) on the housing sufficiently to keep it in position on the shaft, as in the next pictures:
ImageImage
Note: this is looking forward along the drive shaft axis.

As you can see, when the sproket guard is properly secured along the drive shaft, it is centered and cannot move out of position to contact the frame.

Hope this solves your problem (aren't digital cameras fun?)! 8)

Author:  draigue [ Fri May 19, 2006 6:12 am ]
Post subject:  TURBO FINS

Tried mine yesterday on the Chattahoochie. Wind was blowing against the flow 15 to 20 creating large standing waves. My Adventure punched right through them with the turbo fins. Sustained speeds over 5mph were easy. I normally paddle and pedal at the same time, but the turbo fins have so much power I have lost my sync.

Author:  Windrider [ Fri May 19, 2006 11:54 am ]
Post subject: 

OffRoad,
I saw that link and my first thought was the same as stevehman had, and that was that the masts are too long. (I'm not convinced yet that they are not.)

Roadrunner,
Your pictures look just like my drive and the pictures OffRoad posted.

You said "Second, you should have clearance between the sproket guard housing and the frame as seen below."

In your picture there is no clearance, on my drive there is no clearance, in OffRoad's picture there is no clearance. The top of the fin is too wide and that forces the sprocket guard away from the sprocket (about a quarter of an inch) and against the frame. It is just that simple.

Lay one of your old fins on top of the Turbo Fin and you will see the width difference I'm talking about. That coupled with the fact that the fin does not go down far enough on the mast and due to its angle causes the fin to shift even further aft causes the quarter inch difference.

Hey guys, I really appreciate you feedback, pictures, and attempts to help, but you are not going to convince me that this is anything but poor quality control.

As I first mentioned, it will probably not have any effect on performance, (except for a little plastic wear) and I said I was "disappointed" not outraged. Thanks again!

Author:  Roadrunner [ Fri May 19, 2006 2:06 pm ]
Post subject: 

Perhaps I don't understand the nature of your problem. If you had a picture, that would probably help greatly. As you can see, my fin clew draws up into the slot at the bottom of the sproket guard so there is no pressure on the guard. My picture clearly shows a uniform clearance between all four sproket guards and the frame. Tensioning the knurled knob actually pulls the guard and fin together. Am I looking at the wrong area?

My set of fins works great and has no fitment problems at all. Like yours, the sproket notch on the fins appears to be slightly misplaced, but to no significance. Without the gap between the fin head tack and the drive assembly, you would have no adjustment potential, expansion capability, or safety tolerance for non-factory installed "kits". The performance on mine has been beyond expectations! Other than the notch, I'm trying to figure out where there is a quality issue.... I'm not trying to defend Hobie or be argumentative -- am apparently just too dense to see it.

Maybe you got a bad set?? If so, a replacement might be in order. :?

Author:  Windrider [ Fri May 19, 2006 4:21 pm ]
Post subject: 

Roadrunner,
Your picture looks just like my drive and does not show a uniform clearance between all four sproket guards and the frame. Take a look at OffRoad's picture in the other thread of the two drives side by side and the difference is very apparent.

Author:  OffRoad [ Fri May 19, 2006 9:44 pm ]
Post subject: 

Image

Author:  Roadrunner [ Fri May 19, 2006 10:24 pm ]
Post subject: 

Got it -- finally! Thanks. :oops:

Author:  Windrider [ Sat May 20, 2006 9:24 am ]
Post subject: 

OffRoad,
Great picture, thanks for another thousand words!

Author:  AlohaDan [ Sun May 21, 2006 11:57 pm ]
Post subject: 

If there is rubbing it should not take long to see some wear.

Perhaps Offroad and Roadrunner can start a log and take pics at some interval. 50 hours? Whatever?

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