Can someone give me a run down on how weed fin sizes correspond to normal slalom/speed fins please??
For example..... if I would use a 40cm slalom fin in a 65-70cm wide board,what size weed fin would that relate to??
Ive only ever used a weed fin once a couple of weeks ago and it had no drive upwind at all. Unfortunately for this spot you HAVE to use one.
Thanks in advance
Well i use a 34cm 45deg on my F2 SX M (with a 6.4m and a 7.7m)that's 69cm wide. The trick is finding a weed fin that has quite a bit of area so it gives you enough lift.
The 34cm is in fact a techtonic. It stated life as a 50cm Mirage pointer and i got Elmo to rebox it for me. It rips upwind.
I have struggled to find any good weed fins on the market. The JP's and Choco's look pretty good.
Hi KA43,
We use weedies exclusively here, and don't have trouble getting upwind. I think it's a technique issue.
Here's my understanding of it:
With a weedy, the centre of effort of the fin will be further back than with a pointer. This has the effect of making your board want to go more downwind than it would otherwise...
You can still go upwind if you need to, it just takes a slightly different technique. I don't know how the technique differs because I'm so used to weedies now a pointer would just feel weird!
For reference I use a 31cm JP weedy with a 6.8 Blade, no issues there. I also use a 23-ish weedy with a 5m Ezzy, no worries getting upwind there either. I think that the fin sizes are comparable if you consider the depth of the fin measured vertically from the waterline, so a 31cm weedy would be about the same as a 31cm pointer, even though the 31cm weedy would have a lot more area and 'look' longer.
I use these weed/wave fins both in Safety Bay and at Canton:http://www.surfingsports.com/wardog_fin_designs.asp
I think he's stopped shipping them outside the US though. I like them as they seem to provide enough drive while still being fairly shallow fins. They have heaps of surface area compared to some other weed fins, and the centre of effort seems to be further forward too. I weigh 96kgs and tend to drive the back of the board hard and these seem to handle that.
For a 115 litre board I use a 12 inch, and for my 135 litre board (a hi-fly madd) I use two 10 inch ones.
On my smaller 100 litre board I can use the 12 inch, the 10 inch, or a 9.25 inch one I have got, depending on how fast I want to go and how much lift I can handle.
Part of the problem may be with your weed fin.
A lot of them seem to be ordinary fins at an angle, this reduces their flow to thickness ratio, and decreases their aspect ratio. This has the effect of increasing drag and decreasing lift.
I think a good weedy has a thicker chord than an upright fin, so that the water flow sees the usual ratio, (8 - 10%)
I have the same problem as Nebs here, I haven't used pointers enough to be able to give a comparison, but I'm using a 20cm with my 5.2 and a 25 with my 6.0 for speed sailing.
If I only wanted to get upwind, I'd increase a few cm .
I found I needed a smaller weedy than a pointer. Weed fins tend to be fuller/thicker than a race/slalom fin which creates lift and also more surface area.
I have Select eliminator, Fyling objects Weester and a Gsport Sortaweed and they are all good. The sortaweed is the most upright at 53 degrees rake angle but still gets the weed off very well. I think you only need a 40 t 45 degrees if you have really thick matted like weed.
They tend to have good control and don't spinout easily and track well but don't point as high or turn.
Thanks for all the replies.
The one I got is a 31cm Select which seemed a tad small for my larger slalom board. The fin is a lot thicker and has more surface area than a normal pointer so I will adjust me.
I could get it to go upwind but it felt so different than a normal pointer and it did tend to want to go off the wind more, it was my first time
Thanks Nebb's, your explanation made sense.
