Bad enough on 'choppy' water, planing with a 34cm fin, but today took the cake....
, fairly flat-water, planing along (watching gusts), riding over about 20cm 'chop', when the board decided to 'spin-out'!!!
After immediately getting the weight onto my front foot & pulling in the back, I thought I had beaten it, only to relax back into the harness & slide-out straight away.....this went on for about 100-150m, until the thought went through my head that, either - my fin had broken - or fallen out.
quote:
Originally posted by Pugwash
ermmm "spin out"
Got lots to do with size...
fin size
sail size
board size
and
mast foot position
fin position (US box)
boom height
harness line length
footstrap position
sail trim
) I was putting a fair amount of pressure on my back foot trying to get upwind! It happened a fair bit the other day whilst 'attempting' chop-hops...more like 'wipe-outs'. As for heading downwind, I was trying to, but the fin didn't seem to 'take'.
)...
being an older fin, it could have nicks, also could've copped a dose of 'lube' spray (oops, making the surface slippery and maybe coating it), I did spray some gear a few weeks ago.
quote:
Originally posted by Sailhackquote:
Originally posted by Pugwash
ermmm "spin out"
Got lots to do with size...
fin size
sail size
board size
and
mast foot position
fin position (US box)
boom height
harness line length
footstrap position
sail trim
Yeah, thanks for an easy answer
As for the list you mentioned...possibly all wrong, the gear I have is a mismatch of sorts, I'm still trying to get the right combination....unfortunately, the conditions keep changing (weather....funny thing
It's a 'powerbox' fin, so unfortunately that one's out of my hands, as for the rest....I think you're right!
Jord,
I guessed as much,
quote:
Originally posted by 555
I'm going to go out on a limb here - these suggestions have worked for a number of sailors I know(me included) but understand that your gear/person/conditions may cause your results to vary! Anyhow, hopefully this might give you a starting point..
- First, and most important of all! Make sure you have lots of downhaul - you want the top couple of battens pulled away from the mast (assuming you have a mast with a bend curve that matches the sail..), and they should be pointing at the middle of the mast like this: ---O You should see the leech is loose and floppy. Not enough downhaul results in lots of sideways pull from high up - and you instinctively counter that by pushing with your feet. More downhaul will handle a lot of the venting of gusts for you, and catapulting will become much less likely. If you do still manage to catapult, sheet in and hang on as you go around - you're much less likely to smash stuff, and it's good practice for looping later!
- Assuming you're on a modern shortboard (post 98ish) set your mastfoot at 135cm from the tail of the board - you can go forward or back a couple of cm, but try 135 to start with and see how you go. Back will make the steering more twitchy, tend to turn upwind a bit, and increase your chances of getting unexpected airtime ; and forward will hold the nose down, make steering more stable (slower to turn) and will also make it significantly more difficult to get planing. Great if you're caught out when it blows more than expected!
- Get your boom up nice and high - at least shoulder high, but up to eye height is good (stand on your board next to the mast foot to measure) For me, this is right at the top of the boom cut out in most of my sails - I'm pretty tall though. Once you have it right, lay the mast back down the board, and take a note of the distance between the tail of the board, and the bottom of the boom - that way you can set it the same next time you rig up without needing to stand on your board. A high boom will help get your weight off your feet, and onto the mast foot where it should be! It feels awkward to start with, but stick with it because it makes a HUGE difference to everything else.
- Measure your harness line positions - start out with the centre of your front line 1/3 of the distance from the front of your mast to the clew, and the back line up to (not more than) a fist behind the front line. Depending on your sail, this might move a little bit, but the 1/3 rule seems to work (very very close to perfect) on 95% of the sails I have tried it on (the other 5% were really old, so shouldn't really count) Ideally, you want to have a touch more boom pressure on your front hand when you're sailing, but not much.
- Footstraps.. depends a lot on what sort of board, and riding you're doing, but.. Back strap lined up so that the front of the fin is roughly in line with (or forward of) the middle of the strap, and front straps a comfortable width away from the back strap (depends on your build..) and inboard to start with.
With a big fin like that, once you get really planing and want to go upwind, lean forward and rake the rig back like Neb said, push your weight down through the harness to get as much of your weight hanging on the rig (and off the board) as you can, and then point your toes.. this seems like it should carve the board off the wind, but if your rig is raked back enough, you actually lift the board almost off the water and ride the fin. The board becomes a lifting surface in the air, and the fin will drive you upwind faster than you ever thought possible. Probably take a few goes to get a feel for it, and it does require that you have everything else working pretty well first..
Like I said at the start - your gear and conditions may give you different results, but this stuff all works well for me across most of my kit, and is all ideas that I have pillaged from various "experts". [Jem Hall, Guy Cribb and Peter Hart among others]
My key tips are plenty of downhaul (make sure that your mast is the right spec for the sail, or you're already fighting a losing battle) and getting your boom up high. There's no shame in taking a notebook and tape measure to the beach - if it makes you a better sailor, then go for it!
There's really no 'one way' to do it seeing as everyone is slightly different, but if you always do what you've always done: You'll always get what you've always got!
quote:
Originally posted by sorse
Has nothing to do with boom height harness line or anything to do with your rig, but stance may cause it
quote:
Originally posted by sorse
Spin out, it's caused by your fin cavitating, air bubbles around your fin which can be caused by scratches or chips in your fin, check this first, if there are any sand them out with wet'n' dry from the front to the back NOT base to top, weed on your fin is also a cause, look back at the tail of your board when planning, you can usually see the turbulance caused by weed stuck to it.
), that won't stop me, hopefully I'll have company!quote:
Originally posted by 555
---definitely more likely to occur if your fin is damaged (or apparently if they're too shiny!).
quote:
Originally posted by decrepit
Had another thought too if you have a bolt thru the deck fin system, make sure there's a good air seal around the bolts on the deck. If there's a leak, air can get sucked down around the fin.
quote:
Originally posted by nebbian
I wondered what that plastic washer was for!
*runs out to find an O-ring*
