As we wait for this westerly to build, what are people's thoughts on the symptoms of having too much fin for a given board/sail/rider combo?
I'm pretty sure I know the feeling of being underfinned. Struggle to get on the plane, struggle to point, spinouts - the makings of a dud session.
However, I'm not sure what to expect when being overfinned. I've had a Starboard Freeformula with a 70cm formula fin and and well powered 8.5m sail (and a 103kg rider) out and not felt any unusual effects from what popular opinion would define as probably an overfinned setup. Am I missing the clues? Does the overall experience degrade as quickly when you're overfinned vs underfinned?
Cheers. Eckas.
Had a 'bit-too-big' fin on last weekend and as soon as I was overpowered, the board lifted and tail-walked...which is a fair effort seeing as I'm 105kgs!
I'm not 100% sure why, but I know that if I use the right fin, with the right size sail, in the right conditions...It feels awesome! Wrong size fin and it ruins the experience...
Firstly, I can't say that I know the answer to this, but would like to add another example: 148 lt Bic Techno 2 and I am 90kg (on a good day...), 48 cm fin with a 4.7m Aerotech sail. Sailing at Sandy Point with all the speed gurus buzzing around in winds that were 30-45+ knots. One of the guys came up to me and suggested that sailing with a fin that size I must have ankles made of steel, which I certainly do not. However I must say that I didn't feel any ill effects or lack of control on broad reach runs or returning upwind runs. All the other guys were running fins half the size/area as mine but with similar sail size. Now for sure, they were going faster than I was on their gun speed boards, but I certainly felt I was holding my own when I probably should have been changing equipment to suit the conditions. What should I have felt? What should I look for as a sign to swap down fin sizes? What benefits can I expect from changing down?
eckas, trust me, you will know when your over finned
you will know in a few seconds.
The first symptom is that your on the edge of "out of control, and cant get "downwind" (home), board tail walking and all sorts of problems. Your pushing hard out on the back hand trying to take the drive off the sail, and its still driving upwind and all your thinking is "I wana get back to start point..... now
)
Example, was last weekend, I ran a 6.2 Hellcat in a good Westerly down at Bunbury, with a 33 Choco weed fin. When it all went pear shaped, I could have dropped board size down from the 110 to a 91, but was too buggered to change over, so went for a 28 weed fin, and regained some level of control for rest of session. You can drop sail size, but if your experimenting try the smaller fin first.
Mineral
You'll realise you're over-finned when you get moving and all of a sudden the board tries to jump out of the water and attack you.
I'm pretty sure it happens when the board is slightly nose up and banked to the left or the right, the power of the fin (which is now not perfectly vertical in the water) will drive the board upwards. I used to sail a 42cm fin on my 105L board on low wind days to help me point upwind, and once I got a bit of speed going the board would start jumping if I ran across a boat wake and unsettled the board.
so .. useing my 21wave fin on a 75lwave .. would i need a smaller or larger fin as my sails are 5m/4.2m/ 3.7m .. would u 21 suit the 5m and buy a smaller fin for the 3.3m or is it the other way around ??
i tried a 34cm fin once on a 75litre board,it made the board feel like a horse thats never been riden before.
you need strong legs to control extra lift of board.
to small a fin for board width will once powered up make the board feel awesome.
it will ride like a S class mercedes.
i use fin size way smaller than recommended,25cm for 80litre, 28cm for 100litre and 41cm for 150litre. all are stiff carbon which adds to lateral resistance.
the negatives most find with using too small a fin is they spinout at preplaning speeds or at lower speeds.
a simple technique of banking leeward rail with backfoot which lifts windward rail will make it near impossible to spinout.
i use this sailing technique for all points of sailing. reaching, downwind and especially works good for pointing upwind.
