Author Topic: Ventral Fin and fin tests  (Read 10473 times)

ukgm

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Re: Ventral Fin and fin tests
« Reply #75 on: October 12, 2017, 07:49:59 AM »

This setup is more than 10 percent faster than a big single fin with my limited testing. I'm sure that number isn't real, but it's a big enough change to be interesting even without disciplined tests.

Cripes ! Even half that would be impressive.

ukgm

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Re: Ventral Fin and fin tests
« Reply #76 on: October 12, 2017, 07:57:29 AM »
They are now 3.5 inches long and 1.5 inches tall.

Whoa, that small.

I'm amazed any surface turbulence isn't large enough to overcome them and therefore not allow them to function properly and would make the board slide around. That's great work though Bill. I'm still bedding in with mine but I do wonder if the concept isn't so effective on a deep triple concave board like the '17 allstar.

I'm still at the 'replace the kick fin for a ventral' phase......

burchas

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Re: Ventral Fin and fin tests
« Reply #77 on: October 12, 2017, 08:25:25 AM »
They are now 3.5 inches long and 1.5 inches tall...

Are you sure about those measurements? my tail would drift like a puppy happy to see its owner
after a year long vaca. Your board must be sitting so low you could probably run with just a groove
in the back :)
« Last Edit: October 12, 2017, 08:28:42 AM by burchas »
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PonoBill

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Re: Ventral Fin and fin tests
« Reply #78 on: October 12, 2017, 04:45:28 PM »
Me fat, you not. Brain fart though. 5.5 inches long, 1.5 inches high. I took the 9" X 4.5" trapezoidal Larry fin and drew a line from the end of the front overhang parallel to the original edge, then  drew a line parallel to the upper edge the same width as the first line. Cut them on my bandsaw and foiled them with an angle grinder. The idea was to not take small steps--do a big jump and see what happens. When I looked at them I thought "shit--overdid it. these are way too small." But they work fine and track well. Things get very touchy if I pull the ventral fin, but with that in place it goes very well.
« Last Edit: October 12, 2017, 04:59:39 PM by PonoBill »
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