Quad fins with stabilizer fin (some might say knubster)

[Fritzkat]

Strange that Futures or FCS hasnt sent out a new Stubby 5th fin model yet. However, I now use thin packing tape now to cover the unused fin slots and I notice less drag at high speed driving.

[Slowman]

Strange that Futures or FCS hasnt sent out a new Stubby 5th fin model yet. However, I now use thin packing tape now to cover the unused fin slots and I notice less drag at high speed driving.

You mean like this one. I don't know how long it has been out but it is on the FCS website for Oz. I know that Kelly was using it in NY...so perhaps since then.

[Slowman]

... However, I now use thin packing tape now to cover the unused fin slots and I notice less drag at high speed driving.

Now that is interesting. I suspected these open slots were creating some drag and it would be worse in a thruster configuration with 4 plugs vacant.

[Chris]

yeah having the tabs open is less than perfect, but I personally have never finished a session and felt that my empty inboxes were letting me down.

one way to make cheap plug fillers is to take an old set of fins, cut the tabs off and drill 1/16" holes about 1/8" deep into the surface of the tab exposed while the tab is in the box. Then you can use a 1/8" drywall screw to pop the tab out when you need to use the box. Works for both FCS and Futures.

I don't do that myself, but its an easy way and probably more reliable than tape? better for the environment too as its unlikely they will fall out.

[Slowman]

yeah having the tabs open is less than perfect, but I personally have never finished a session and felt that my empty inboxes were letting me down. ...

Nor I but without having ever tried it and not knowing the difference you can't recognise whether there is any detriment.

Some polyurethane tape cut to circles would fit nicely over FCS plugs and seal out water too. We've been using this stuff to protect our nice carbon fibre frames in mountain biking for years now. You wouldn't want the same grade as used for frame protection as it has quite a strong adhesive which would make removal interesting - it could possibly tear off the finish coat. This stuff is used to protect helicopter blades too (aka helicopter tape). So reliability wouldn't be an issue though re-usability might be, you could perhaps re-use it a few times whereas the fin tabs would be re-usable indefinitely.

[Mana]

perhaps some silicone filling out of a tube or self-adhesive sealing tape cut to measure would do the trick as well? and removal wouldn't cause harm to your board. or just use stickers.

[Fritzkat]

The super thin packing tape works great in the Futures rear quad fin holes (FUTURES have a much larger slot to cause turbulence drag.), after 20 sessions nothing has fallen off. Good for quicky ding covers as well. I would like to get a futures stubby fin when I ride it as a Quad. I just saw that FCS stubby posted by slowman. I may just cut an old composite fin down and try that for size.

[Alberto]

since the NY Quik Pro i had been itching to try a knubster/guitar pick on my 5'8'' dominator and thanks to slowman i finally got around to foil an old G5 fin i had laying around. I more or less copied slowman's design to use it with my R-2 quad set:



Well, i took the board out today (in 3' to 4' long walled rights with a light offshore) and the board felt incredible. Very fast and drivey.

You get the feeling the knubster doesn't create any extra drag and just manages to give a bit more hold to the quad set. I usually prefer to ride the dominator as a thruster in any kind of surf over 3', but from now on i will now try to use this setup more, especially in waves with long sections.

I think the dominator with it's large tail is particularly suited to this kind of setup.

[Chris]

Alright....

So folks. I am actually taking this thread really seriously. I want to know from the people who have tried riding the knobby style fin the following:

Board model
Board length
your weight
surrounding fins


pretty interesting stuff....I want to archive it!!

Thanks all for the progressive approach!

[Slowman]

Model: FST 6'0 Dominator
Length: 6'0"
Weight: ~92kg
Fins: FCS R-2

So far both test cases, mine and Alberto's are using Rusty R2 quad sets, I am thinking of testing this set up with K2.1 quads as well. I also have some other ideas for the shape of the stabiliser that I want to try too.