Does anyone think this will work?

I'm looking forward to testing it.

DJ

Hey DJ
I am wondering because you have the same surface area of fin and now you will have a flow of water between the bolts it may be worse as your board tips from side to side, because whatever stabilityyou get from a normal fin comes from the water trapped in the 90 degree area that it makes. Lacey will know for sure
Cheers Boof

BruceT said...

As long as it doesn't break off when you hit a jellyfish, hula-hoop or whatever else is floating around in the bay

Ha.. I'm looking forward to slicing up some jellies..

The big thing will be remembering to hope off before it gets too shallow..

DJ

DavidJohn said...

boofy said...

Hey DJ
I am wondering because you have the same surface area of fin and now you will have a flow of water between the bolts it may be worse as your board tips from side to side, because whatever stabilityyou get from a normal fin comes from the water trapped in the 90 degree area that it makes. Lacey will know for sure
Cheers Boof

High speed and windsurfing this would not work.. but at our slow paddling speeds it just might work.

I'm thinking the fin area close to the board does not do much for stability and is mostly there to join the part of the fin that does to work (the bit more towards the tip) and the board.. I'm thinking that it will change an 11" fin to a 13" fin.. I'm thinking it should be quite noticeable.

DJ

Yeah Ok so it is more of a leverage principle, I hope it works, imagine the bolts as a slim aerodynamic carbon rod you may be onto a good thing
Cheers Boof

dj, i'm going to guess you will get a keel/ pendulum effect. i think it might 'draw out' the tippy ness .


interesting, let us know how it goes for you

cheers

aus301 said...

It might work while you are paddling along under your own steam, but my guess is as soon as you get on a decent runner and get the board going a bit quicker it will cavitate, probably making the board less stable and slower.

I'm thinking of only using this while paddling flat water and only up to my max paddling speed.. Not surfing.. Not even catching runners.. Just flat water.. and river use where the odd boat wake often causes me to struggle.. I'm just trying to slow down that quick initial tip that these boards tend to have if you are tall, heavy and clumsy.. I can't see how adding little side fins like Lacey's would help me much and big long fins are very hard to find these days because they are all for power boxes.

DJ

agree dj. the bonzers keep the board straight, whitewater grip and some stability. but i don't think they would do much for what you are looking for.

have tried a reasonable sized broad based fin

Yes.. I've been using a 11-12" dolphin fin and that helps some.. I'm not a big fan of board based fins like most weed fins because they often have less area in the fins tip.. and that's where you need area if you're after stability.

DJ

SandS said...

I recon you will feel it slow you down even while paddling in flat water. Too much drag.

Will be interesting to here your comments, after testing .

I think a longer fin would have less drag than the two bits of all thread.

Maybe it will.. But I can't get a longer fin.. If I could I would not have gone to this much trouble.

I'm not sure if the s/s shafts will create much drag at our slow speeds.. and should be so little I doubt you could feel any difference.. My main concern is flex in the shafts.. I might need three.

I might have to mount my GoPro under my board to see what's going on as I paddle..

I can feel a big difference in stability going from an 8" fin to a 10" fin.. Or even a 10" to a 12" fin.. So I'm hoping this will make a noticeable difference.

DJ

What about a retractable centre board DJ? get the Jig saw out . I have paddled an old D2 wind surfer a fair bit on flat water ( super round long skinny thing) Its about 24 inches wide and very unstable at rest but fine when moving. if I am turning around or boat wake is comming I just give it a bit of centre board (its fully retractable) and its more stable then a 30 inch flat bottom.
I recon this concept could work for flat water race boards allowing them to get the width right down as you only need the stability of wide boards when starting off or turning.
The board makers would hate it though as its a bit of mucking about to make a good retractable centreboard.

Nev

nev said...

What about a retractable centre board DJ? get the Jig saw out . I have paddled an old D2 wind surfer a fair bit on flat water ( super round long skinny thing) Its about 24 inches wide and very unstable at rest but fine when moving. if I am turning around or boat wake is comming I just give it a bit of centre board (its fully retractable) and its more stable then a 30 inch flat bottom.
I recon this concept could work for flat water race boards allowing them to get the width right down as you only need the stability of wide boards when starting off or turning.
The board makers would hate it though as its a bit of mucking about to make a good retractable centreboard.

Nev

Now you're talking.. Great idea..

DJ

DavidJohn said...

aus301 said...

I could be wrong, but I think with a bit of time and effort you could cut and sand a power box base to fit a US box. Drill a couple of holes, pin and drill and you are away.

That just might work.. I'm still keen to try my fin idea because it's only cost me $5 so far for the s/s bolts.. .. and it's a fin that I don't use.

DJ

or attack an old tuttle box slalom sailboard fin with a grinder.....similar to what aus301 said.
I cant remember how long those things got back in the day....but well and truely long enough and designed for speed.
Carbon too....nice and stiff.
Nice little weekend project.

DavidJohn said...
I can't get a longer fin.. If I could I would not have gone to this much trouble.

Do you need more length or more tip area? You know how balance-challenged I am DJ...I've been chasing stability-nirvana for a good while. Larry's Gladiator fin makes a huge difference to the roll stability of my DC compared to other fins. Yes it has a big base but the tip is big too and makes it MUCH more stable.

I was also looking at one of these from Curtis for the 17

http://www.curtisfins.com/store/index.php?route=product/product&path=36_37_45&product_id=49

not necessarily the concept you're chasing but might have the desired effect (cost more than $5 though )

This McTavish should do the job.

62mac said...

SA I was talking with Bob last week and I mentioned how I was having trouble with one board I have,his first question was what fin I was running,10 mins later all sorted,fin change and next surf I have a board that I control.

The board went from a dog to a joy to ride.

DJ I'll be seeing Bob Wednesday and I'm sure going to ask him about your bolt fin idea.

Thanks.. Say hi to Bob and see if he remembers me.. (not as DJ but as David Peterson) .. He might remember me from riding Mike Maguire windsurfing boards.. and coming in to watch him shape mals in Ballina when he was there.. and having some great windurfing sessions at Flat Rock in mast and a half high conditions with him.

The whole bolt fin idea is more about making a smaller fin longer when you can't find a longer one.. You never know it just might work better than a normal fin because normal fins that touch the board create low pressure areas and can suck air down from the base of the fin.

DJ

what was that cut away fin? it looked pretty good

lookToSea said...

what was that cut away fin? it looked pretty good

That's the fin that I was using.. It's locally made by a guy in Totquay and he calls them 'Glide' fins.. It works ok but I'm looking for something even better.. I might get him to make me a custom fin.. I used to make my own fins in my windsurfing days that was a modified dolphin shape.. I don't have any now and I might have to do a drawing of one to show my design.

DJ