Get this!

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Roy_Stewart
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Re: Get this!

Post by Roy_Stewart » Wed Nov 05, 2014 3:55 pm

Hi Mr Mik,

Looks like there are some sloppy box installers around.

When you say that the pin doesn't go into the slot on the Meyerhoffer, do you mean that the main slot of the box is nnarrower than the fin tab, making the tab too tight to enter the slot?

That can happen sometimes if the box is installed without a spacer (which keeps the slot at the right width as the resin is setting.

Drailed
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Re: Get this!

Post by Drailed » Wed Nov 05, 2014 3:57 pm

I gotta ask Mr Mik, with the greatest of respect... how the f**k can you be bothered to do all this, especially the swimming pool bit??
Trev wrote:I have always had a lot of time for Dick
smnmntll wrote:Got one in the mouth once, that was pretty memorable

Roy_Stewart
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Re: Get this!

Post by Roy_Stewart » Wed Nov 05, 2014 4:07 pm

If, on the other hand the tab is entering the main slot on the box but the pin won't enter the groove which it is supposed to slide in, then sand a bit off the bottom of the fin tab at the pin end of the tab ( and if necessary the entire bottom of the tab) and the rounded area adjacent to the pin, thus allowing the pin to drop down a bit further. It shouldn't need more than nalf a mm or so unless the manufacturer screwed up badly. This won't affect how the fin fits in the 8 footer.

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MrMik
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Re: Get this!

Post by MrMik » Wed Nov 05, 2014 4:52 pm

Roy_Stewart wrote:If, on the other hand the tab is entering the main slot on the box but the pin won't enter the groove which it is supposed to slide in, then sand a bit off the bottom of the fin tab at the pin end of the tab ( and if necessary the entire bottom of the tab) and the rounded area adjacent to the pin, thus allowing the pin to drop down a bit further. It shouldn't need more than nalf a mm or so unless the manufacturer screwed up badly. This won't affect how the fin fits in the 8 footer.
Yeah, thats the problem and the fix for it, but I cannot be bothered. The Meyerhoffer was just next to the McCoy longboard in the rack, with an empty box beckoning to try the fin for fit. I figured that as a pop-out board, it might have a standardised finbox. I don't think I'll surf it again, with any fin, I have so much more fun on a McCoy every time.
I gotta ask Mr Mik, with the greatest of respect... how the f**k can you be bothered to do all this, especially the swimming pool bit??
I bet people like George Greenough and anyone shaping fins would at times have used some techniques involving hand-held fins in swimming pools to figure out what works.
I hope to spend many hours per week on a surfboard for a few more decades, so putting in a bit of an effort to try to understand how the stuff works, and what works best for myself, is well invested time. Besides, it is actually very interesting. I'm looking forward to today's experiments with more fins that are much more different from each other.

Roy_Stewart
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Re: Get this!

Post by Roy_Stewart » Wed Nov 05, 2014 6:26 pm

We do the pool trick too :-)(

Drailed
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Re: Get this!

Post by Drailed » Wed Nov 05, 2014 7:09 pm

Cool mate. Enjoy :-D-:
Trev wrote:I have always had a lot of time for Dick
smnmntll wrote:Got one in the mouth once, that was pretty memorable

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steve shearer
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Re: Get this!

Post by steve shearer » Wed Nov 05, 2014 7:47 pm

For fcuks sake MrMik stop flapping your gums around like an old fish wife and get that fin in the surf.
I want Nightclub Dwight dead in his grave I want the nice-nice up in blazes

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kayu
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Re: Get this!

Post by kayu » Wed Nov 05, 2014 8:03 pm

Roy_Stewart wrote:We do the pool trick too :-)(
It's far cheaper than sending it to the test tank in Tasmania , and almost as effective !... :wink:

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kayu
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Re: Get this!

Post by kayu » Wed Nov 05, 2014 8:05 pm

steve shearer wrote:For fcuks sake MrMik stop flapping your gums around like an old fish wife and get that fin in the surf.
What's up Steve , are you pissed because MrMik got a gull-whale fin before you ? :d

Roy_Stewart
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Re: Get this!

Post by Roy_Stewart » Wed Nov 05, 2014 8:30 pm

The Gull Wing Affair continues. :-o

Are we going to get a look at your wooden version kayu? I suppose that Mr Mik will give us a peek at some point. What sort of foil thickness are you going for?

Hollowed out
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Re: Get this!

Post by Hollowed out » Wed Nov 05, 2014 9:01 pm

mr Mik
Several statements you have posted tend to indicate you have a lot of money and time to spend as indicated by the following.
"I used my lunch break to test-fit the Gull-Whale fin into the best surfboard in the entire world: My 8'0'' Nugget".
Secondly, even that you have a meyerwhoofer, lying around in your garage, wtf.
Thirdly you are getting "Geoff" to make you a replacement board for one that is 14 years old and you do all this stuff in a fcuken pool leaves one to the conclusion that any possible outcome/information your purported research may reveal would be of very questionable of not fcuken useless to anyone within 100 klms of a place where the activity of wave riding may take place.

There are a lot of charities out thee that could really benefit from that excess of time and money you may wish to re direct your 'science' toward. Just a thought.

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kayu
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Re: Get this!

Post by kayu » Wed Nov 05, 2014 9:07 pm

Hollowed out wrote:mr Mik
Several statements you have posted tend to indicate you have a lot of money and time to spend as indicated by the following.
"I used my lunch break to test-fit the Gull-Whale fin into the best surfboard in the entire world: My 8'0'' Nugget".
Secondly, even that you have a meyerwhoofer, lying around in your garage, wtf.
Thirdly you are getting "Geoff" to make you a replacement board for one that is 14 years old and you do all this stuff in a fcuken pool leaves one to the conclusion that any possible outcome/information your purported research may reveal would be of very questionable of not fcuken useless to anyone within 100 klms of a place where the activity of wave riding may take place.

There are a lot of charities out thee that could really benefit from that excess of time and money you may wish to re direct your 'science' toward. Just a thought.
...(lol)...(wow , another one with a bug up his arse for no apparent reason... :) )....at least you must feel better now ?

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kayu
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Re: Get this!

Post by kayu » Wed Nov 05, 2014 9:20 pm

Roy_Stewart wrote:The Gull Wing Affair continues. :-o

Are we going to get a look at your wooden version kayu? I suppose that Mr Mik will give us a peek at some point. What sort of foil thickness are you going for?
I'll laminate the fin blank and pass it on to the experts....I did do the box install yesterday. It's about 1mm proud in the centre of the box , and a couple of mm at the ends. Still has 2 coats of epoxy to go....It will be roughly 12/14 mm thick....the foil will probably be a 753 Kanaka foil , with a high performance box tab.

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MrMik
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Re: Get this!

Post by MrMik » Wed Nov 05, 2014 10:32 pm

steve shearer wrote:For fcuks sake MrMik stop flapping your gums around like an old fish wife and get that fin in the surf.
Easier said than done.
If I manage to eek out a bit of time for surfing, I'll just use my favourite board with the usual fin. I think I've surfed twice in the past 2 months, it's tragic.
If anyone here is waiting for me to write some competent ride report of the Gull-whale fin, then don't hold your breath...my surfing ability is such that I will probably not be able to feel the difference. For now, I'll have to re-learn what my board feels like in the water, full stop. Then I can compare to what happens with a different fin.

OK, back to the fins in the pool experiment:
The only somewhat repeatable and comparable movement pattern that I could find so far is this: Hold the fin at the base, ideally with just 2 fingers, then make it move in the tightest possible figure-8 pattern, as fast as possible, while using the least amount of force.
In this test, the Ben Lexcen Star Fin performs way better than the Gullwing and GullWhale fins, and the Gullwing and Gullwhale fins are clearly better than dolphin fins of comparable size.
With the Star-fin it feels like it is actually easier to do the figure-8 with the fin than with an empty hand! >><<
The Gull-whale fin seems to be the one that can be coaxed into the figure-8 movement with the least amount of force, a few times I got it going with just two fingers on it. That might be due to the lightness of the material or something else, not sure.
The arc or size of the figure-8 is smallest with the Star-fin.

I might be wrong, but I think this test could reflect how well a fin will do for short-arc surfing and/or pivoting.

Another insight from today's test is that the Star-fin is a most interesting and probably also a most fickle beast. No wonder Geoff McCoy does not recommend it for his boards, it seems to be the opposite of 'neutral'. The slightest change in angles brings about a rapid and very definite change in the forces exerted on the fin by the water. It develops amazingly strong lift and drag forces when pushed at just the right angles, but the transitions are very sudden and I think the various "sweet spots" are small and temperamental. A fin for highly skilled surfers that will make surfing more difficult for many others, I think. And I think even I might be able to tell apart the Starfin from the others in a surfing "blind" test. I have had the Starfin for a while but never used it. It came as an unexpected freebie with a used Zot I bought.

damo666
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Re: Get this!

Post by damo666 » Thu Nov 06, 2014 7:27 am

MrMik wrote: then make it move in the tightest possible figure-8 pattern, as fast as possible, while using the least amount of force.
....I might be wrong, but I think this test could reflect how well a fin will do for short-arc surfing and/or pivoting.
Why does a fin that requires the least amount of force make it better?

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MrMik
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Re: Get this!

Post by MrMik » Thu Nov 06, 2014 8:01 am

damo666 wrote:
MrMik wrote: then make it move in the tightest possible figure-8 pattern, as fast as possible, while using the least amount of force.
....I might be wrong, but I think this test could reflect how well a fin will do for short-arc surfing and/or pivoting.
Why does a fin that requires the least amount of force make it better?
I don't know if it does make it better.

What it might mean is that the fin can move through the water with very little resistance and in a very tight arc. As is "short arc, high performance surfing". That's exactly how I don't' surf,so I can not test it in the surf. The "figure-8 test" feels fairly repeatable to me, because I can easily assess the figure-8 radius, and the speed/frequency per turn and force required.
Maybe the figure-8 test assesses how
Assessing a fins "drive" seems much harder because it is in my opinion very hard or impossible to hold the fin at a specific angle while pulling it through the water in a straight-ish line at speed.

However, another quite obvious lesson from yesterday's test is that a spa bath is sometimes even better than the pool for this sort of test, nice and warm....

Next, I'll take my set of Red-X MR twin fins to the pool to experience how the asymmetric foil of side fins feels in the water. And that Turbo-tunnel....

Seriously, for those who find this strange, I cannot believe I have not done this years ago. Highly recommended for anyone interested how surfboards work.

How do other people test their fins in the pool, and what is that Tasmanian test lab Kayu mentioned earlier?

damo666
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Re: Get this!

Post by damo666 » Thu Nov 06, 2014 5:36 pm

Again - and I'm not trying to be a prick - but what are you trying to test in the pool? What were you looking for before you jumped in?
And how, if at all, will you be able to correlate the minor differences you may find to how it surfs?

I'm with Steve on this one, just surf em and see which you like best.

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kayu
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Re: Get this!

Post by kayu » Thu Nov 06, 2014 7:40 pm

MrMik wrote: How do other people test their fins in the pool, and what is that Tasmanian test lab Kayu mentioned earlier?
The test tank in Tasmania is a facility for the boat and marine industry to test scale models of boat hulls for statistics that enable them to build more efficient boats and ships. When a scale model is moved through the clear glass test tank , it is filmed from all angles , and has electronic sensors feed data into a computer to calculate drag , efficiency of planing at various speeds , whetted surface area at different speeds , flow metrics of hull form etc etc . I did some some work years back with a guy who claimed he spent somewhere between 50 and 100 grand to design a surfboard hull that would out perform anything else....(lol).....he did have some very highly ranked surfers on these boards , and many people still ride them and say they are great boards...... I didn't like them myself.......However , a curios mind should never be discouraged MrMik , and your experiments in the pool should give you insights into fins as valuable as spending a squillion bucks in the high tech test lab , minus a mountain of documented data printed on half a forest worth of valuable living trees........the question for me is " why is drag regarded as a dirty word in the surfboard world ? "....because without drag , surfboards won't work at all.....

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