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Finbox canting

Posted: Fri Dec 07, 2012 12:57 pm
by Tom
Hi

I am building three fin raceboard and wondering should i put front fin boxes cant 3 or 0 degree.
Issue is that we have many Select slalom fins allready and i can use them, my son compete slalom in windsurf.
I only think compete national level. If interested more racing then i might want original kiterace fins.

If I put finboxes 0 degree and fins are also 0 degree, is it horrible to ride?

What are advantages if I put finboxes 3 degree?

Is this question irrelevant, just put finboxes 3 degree or something different angle?

Br Tom

Re: Finbox canting

Posted: Fri Dec 07, 2012 4:45 pm
by BWD
No cant is usually considered fastest.
Also hardest to ride.
As a build, it would probably be easiest to put boxes in without cant.
I would build the boxes with no cant, and start with smaller fins, work up to bigger fins.
Also, you can grind fin bases down and pot them to change cant, toe-in and rake if needed...
Good luck!

Re: Finbox canting

Posted: Fri Dec 07, 2012 5:32 pm
by ChristoffM
I think go for 3 degrees. Unless you have another tri fin race board, don't make it 0 degrees and then you might find race boards slightly less fun I'd say. I build two tri fin race boards now, and adding the 3 degrees can was not that difficult, and the board rides quite nicely with standard windsurf fins in the 40cm size range.

If you then invest in kite fins, I am sure you can order them with no cant in the fin so that the board will have 3 degrees cant with windsurf or kite fins?

I do not think smaller fins would make up for no cant. The cant is to help with lift to get the board planing better. With no cant I think you would need to balance on the leeward rail better to get the board planing nicely. Smaller fins will make this even more difficult. Or have I got the plot missing here?

Re: Finbox canting

Posted: Fri Dec 07, 2012 6:09 pm
by BWD
with no cant or toe, there is less drag, and both fins make maximum lift at the same trim angle.
That is why it's said to be fastest.
But it's also more on-off, unforgiving.
The longer the fins, the more unforgiving.
Therefore start smaller like 20-25cm not 30+ I think.
Also swept fins would be easier at first, not quite as efficient (but neither is falling in).
If you are looking for speed, you might rather fool around with potting fin bases to get the right angle than be locked into too much cant.
Another thing that can help with tuning is to use a longboard type fin box in the center to adjust the rear fin forwards or backwards a few inches -this also might require some finbase mods....
Absent lots of experience, I would only try to lock into a fin cluster and canted boxes if making a close copy of another board.