I recently purchased both a Severne Dyno 105 and a Fox 105. Skill wise I'd consider myself to be an advanced beginner (just waterstarting and getting into straps). I've been mostly windfoiling the last year and a half and am now trying to get more time on the fin.

I've got a bunch of fins (see below text and pic) but unsure what I should be using when and how interchangeable these all are. The problem is that my technique/experience is poor that it's difficult for me to assess if a fin is doing the right job or not. My main aim at this stage is getting planning, straight line bump and jump, and managing to stay upwind.

Main questions I have:
- Anyone have experience with the Dyno and/or Fox and can share learnings on fins. Did people find stock fins to be adequate?
- Based on the fins I've got what pairing would you recommend? I'm just looking for a rough no brainer recommendation for someone with my skill level.
- Do I need more fins (e.g. smaller sizes to pair with my smaller sails, will the 36cm fin that came with my Fox work with my 4.7)
- Are the K4 3SW fins meant to paired with thrusters? The size guide chart (see link below) seems to indicate that you only need a 28 for a 6m with a 105 board which seems to break the (SailSize * 5 + 4) rule if used as a single fin. Is that size guide assuming therefore thrusters are attached as well?
- Should I be using the Fox fin on the Dyno or is that just weird and pointless (free race fin on a freewave board)?
- What do I need to look for to know if I don't have the right fin?
- As a beginner should I be using a bigger fin than is recommended for someone more experience (in order to get planning earlier, etc)




The fins and sail I have are described below. I weigh 82kg and sail on Port Phillip bay (Ricketts Point, Hampton, Mentone mostly)

The Dyno 105 came with the stock thruster setup (220 main and 125 thrusters, rightmost fin set on pic) and the Dyno 105 came with a 36 fin (left most fin in attached pic).

They guy who sold me the Dyno also gave me a couple of K4 3SW fins (26 and 28, the two yellow fins on the right of the pic).
www.surfsailaustralia.com.au/product/k4-fins-3sw-freestyle-wave-power-base

On a whim I also purchased a freeride K4 Fang 32 from SQH a few weeks (still haven't opened it and could return if required). I was after a 34 to pair with my 6m Gator (based on 5*SailSize + 4 calc) but they were out of stock so bought the 32.
www.surfsailaustralia.com.au/product/k4-fins-fang-freeride-power-base

Sail wise I have
- 7m FoilGlide2 (which I could use on a fin)
- 6m Severne Gator
- 5.3, 4.7, 4.2 Severne Blades

I have a fox 105, and I found the stock fin good. I use this board with gator 5.7 up to 7.5 ncx. If its windy enough for smaller sails then i use a smaller board.
I recently bought a 35cm carbon fin from Atomic surf for the fox. It is definitely superior for high wind control and therefore speed. It is amazing fin. I use it primarily with a very well powered up 6.2. Its a brilliant combination.
Having said that, I have sailed for around 30 yrs.
I wouldn't be too concerned about making lots of fin changes yet. I reckon the more things you change with your equipment, the longer it can take to really get the feel of it. Just get out there and sail what you have - it works fine. Technique advancement through practice is your best method of improving, rather than fussing with gear.

Hi, you have a lot of questions - and about two boards with several fin options. So you almost have too much choice here!

But the basic answer remains the same for all fin use - both boards here are supplied with the right fins for average use, so start with those fins.
Whilst, as a learner, you can tend to overload the back foot, it's still best to use the fins as supplied, rather than to cover up your technique mistakes with oversize fins.

I haven't sailed the Fox but this is a single fin board where you should match the fin length to the sail size used. A bigger rig can require a longer fin or more fin area, because the bigger sail area puts a greater sideways load on the fin when you sheet in. The 36cms fin should work just fin with your 6m and 7m rigs.

I have had several Dynos and this board is very versatile and is easier to turn and has the better wind range if used as a tri fin. You only use a single fin with the Dyno when blasting with bigger sails - of 6m and bigger. The sail match sizes for that single fin set up in the Dyno would be the same as for the Fox, but given you have these two boards, I'd suggest keeping the Dyno as a tri fin, and use it with the 6m Gator and the Blades.

My tip would be to keep using both boards with the same respective fins, and then learn to sail them, rather than continually changing fins - because that constant will help you improve technique.
When learning we tend to overload the back foot too much for two reasons: Firstly because it takes a while to learn to direct the rig load through the mast foot and secondly, because many people set their harness lines to far forwards on the boom and the uneven load on your hands then loads your back foot, causing the fin to spinout.

Hope this helps.

I'm definitely not super experienced but I found the dyno (I have a 115) to be good with the stock thrusters.

I also like it with a 33cm single freewave fin. Each one feels different.

After playing around a bit with fins, including a 40cm K4 Fang on the dyno with the straps in the outboard position and with sails at the high end of the recommended range (7.5-8.0), I'd say:

Stock fins are best for sails in the recommended range, except if there are weeds. Leave it in 3 strap setup. I also keep my side fins in the backmost position and haven't experimented with trimming those yet.
33cm single for the dyno (would be 31-32cm for your dyno) is great for bump and jump with less steering ease but a little earlier planing.

40cm fin for this with the straps in the outboard, which is a big fin for this board, feels great for straightline and early planing, but that's not really what this board is for. It is very stiff when you try to turn it. The geometry of the board just makes it weird, but it's sailable on a very light wind day and when all I brought was the dyno.

But, as Basher said, I'd leave the dyno set up in 3 strap thruster mode with stock fins and switch to the 4 strap fox/single fin mode if it's really flat and lighter wind. Get more time on the water with both with the stock fins before changing everything up, because you may not be able to figure out what's going on, like why you're not planing. Compared to my other boards, the dyno needs a little more oomph and downwind to get going, I think my much older JP 102 is a little less demanding in similar conditions, but not as turny in the waves as the dyno. Unless you're super well or overpowered on it you'll likely want to point more downwind, feet out of the straps, and learn how to pump it onto plane before slipping into the foostraps. I can sail it subplaning in the straps, even in the waves, but it's better to stay with the front foot up by the mast base until there's a good gust then get planing and slip in. Not sure what board you rode before but it's different.

The only reason I would recommend really messing with stock dyno thrusters is if you have a weed problem. I have a mfc weed wave and k4 dugongs with the same length as the stock thrusters and those work excellent for blowing through the weedbergs we get here in our bay.

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cleverku said..
I recently purchased both a Severne Dyno 105 and a Fox 105. Skill wise I'd consider myself to be an advanced beginner (just waterstarting and getting into straps). I've been mostly windfoiling the last year and a half and am now trying to get more time on the fin.
I think both those boards are a bit ambitious for someone just waterstarting and getting into the straps.

I've got a bunch of fins (see below text and pic) but unsure what I should be using when and how interchangeable these all are. The problem is that my technique/experience is poor that it's difficult for me to assess if a fin is doing the right job or not. My main aim at this stage is getting planning, straight line bump and jump, and managing to stay upwind.
Use the largest ones for each board to start. The OE 36cm Fox fin and probably the K4 28cm 3SW fin for the Dyno. I cant think a benefit for using thrusters at your level for your needs. Myself, I wouldnt bother with thrusters for getting planning, straight line bump and jump, and managing to stay upwind.

Main questions I have:
- Anyone have experience with the Dyno and/or Fox and can share learnings on fins. Did people find stock fins to be adequate?
People I know who have both boards find the stock fins very good.
- Based on the fins I've got what pairing would you recommend? I'm just looking for a rough no brainer recommendation for someone with my skill level.
- Do I need more fins (e.g. smaller sizes to pair with my smaller sails, will the 36cm fin that came with my Fox work with my 4.7)
If its windy enough for a 4.7m use the Dyno?
- Are the K4 3SW fins meant to paired with thrusters? The 18, 20 & 22 3SW maybe, but larger sizes as a single fin in most cases, unless you are very heavy.
The size guide chart (see link below) seems to indicate that you only need a 28 for a 6m with a 105 board which seems to break the (SailSize * 5 + 4) rule if used as a single fin. Is that size guide assuming therefore thrusters are attached as well? Its not a rule, just a guide incase you cant workout what to use. I think its more reverent to larger freeride boards and intermediates.

- Should I be using the Fox fin on the Dyno or is that just weird and pointless (free race fin on a freewave board)? If its light winds so you need a 36cm fin use the Fox. I think if you just had a Dyno, using it with a larger single fin like that would be ok.
- What do I need to look for to know if I don't have the right fin?
- As a beginner should I be using a bigger fin than is recommended for someone more experience (in order to get planning earlier, etc) Yes, to start. As you progress and your skills get better you can get away with smaller fins.

Comments imbedded bold.
Good luck.

^^^ I agree

You should sell one and buy a cheap 125-130L freeride say 5-10yrs old. The Dyno and Fox are so close in usage that I dunno why you'd buy both in same volume

Thanks all for the replies, some great pearls of wisdom in all the comments.

I think main things I've taken away regarding the fins is:
- For the Dyno, stick to stock thruster setup, move the thrusters all the way back. I went out yesterday on my 4.7 on the Dyno with the thrusters and had an absolute blast in this setup.
- Keep the fox for lighter winds and my bigger sails (6m, 7m) and just use the stock 36cm fin.

I might start a separate thread on this one but keen to understand more on board choice and volume spacing. I have the Fox and Dyno in 105L but also have a JP Magic Ride 129L (which I only bought so that I could uphaul and only used a couple of times). If I've got 3 boards to sail on the Port Phillip bay where it's quite choppy what are people's thoughts on ideal 3 board quiver. I've bought everything second hand and pretty cheap so not too concerned with costs switching my existing setup around. Was thinking maybe the following:
- 120L Fox
- 105L Fox
- 95 Dyno

alternatively 2 board quiver
- 120L Fox
- 95 Dyno

I weigh 82kg.

For those shaking their heads, yes I'll admit to being a bit addicted to buying and selling used gear in search of the perfect setup. Every time I think I'm done with buying new stuff something comes up on Seabreeze that I have to try.

Only thing I'm shaking my head about is the claim that you can be an experienced windfoiler without knowing how to ride a sailboard.
99% of people go from fins to foils

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Mr Milk said..
Only thing I'm shaking my head about is the claim that you can be an experienced windfoiler without knowing how to ride a sailboard.
99% of people go from fins to foils

I didn't say I was any good, just that windfoiling is how I've been getting on the water for the last year and a half.

For full disclosure I windsurfed a lot 20+ years ago in my teens and early twenties, spending most of my summers mooching around the sailing/windsurf club with nothing else to do but windsurf. That experience was mostly in sub 15 knot conditions though, on bigger boards (170L with centreboards), non planning conditions, no footstraps or harness required, always uphauling.

I got back into windsurfing a couple of years kinda accidentally when the local windsurf shop went out of business and everything was half off. Enticed by the opportunity of a bargain I bought a Starboard Carve 124L freeride board and because it was so cheap also bought a Fanatic Stingray 140L foil board and a foil (thinking I would eventually progress to the foil once I was comfortable on the fin). I spent the next two months struggling on the fin board just getting blown downwind on to the rocks trying to waterstart. It was frustrating, exhausting and I wasn't getting any of the thrills I was after. Then I tried the foil board which I could just uphaul and from there my previous reflexes all seemed to kick in. Have I mastered the foil jybe? No, but I can get the straight line thrills I was after that I couldn't get on the fin.

Agreed though wind foiling isn't your typical beginner path into windsurfing.

I would get only upright slalom fins for the Fox 105. No need to use anything with a curvature!

The Fang is ok. But I switched from a Fang 30 to a Tectonics Falcon 30 on my RRD FSW 85 with a 6.0 Point-7 ACX and it is day and night (and more than twice the cost). For the Fox with a 6.0 I would get a 33 Phoenix tectonicsmaui.com/collections/race-fins/products/phoenix-pwa-slalom, or something similar if shipment to Australia is not an option.

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duzzi said..

The Fang is ok. But I switched from a Fang 30 to a Tectonics Falcon 30 on my RRD FSW 85 with a 6.0 Point-7 ACX and it is day and night (and more than twice the cost). For the Fox with a 6.0 I would get a 33 Phoenix tectonicsmaui.com/collections/race-fins/products/phoenix-pwa-slalom, or something similar if shipment to Australia is not an option.

For the aspiring intermediates here, could you describe what you mean? I've got the stock 44 choco, 43 select pro, and two weed fins for my Blast 145 and I'm wondering what an upright fin like that would do vs. a swept fin.

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duzzi said..
I would get only upright slalom fins for the Fox 105. No need to use anything with a curvature!

The Fang is ok. But I switched from a Fang 30 to a Tectonics Falcon 30 on my RRD FSW 85 with a 6.0 Point-7 ACX and it is day and night (and more than twice the cost). For the Fox with a 6.0 I would get a 33 Phoenix tectonicsmaui.com/collections/race-fins/products/phoenix-pwa-slalom, or something similar if shipment to Australia is not an option.

That fin and sail on a FSW sounds like you've entirely missed the point of the board.

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aeroegnr said..

duzzi said..

The Fang is ok. But I switched from a Fang 30 to a Tectonics Falcon 30 on my RRD FSW 85 with a 6.0 Point-7 ACX and it is day and night (and more than twice the cost). For the Fox with a 6.0 I would get a 33 Phoenix tectonicsmaui.com/collections/race-fins/products/phoenix-pwa-slalom, or something similar if shipment to Australia is not an option

For the aspiring intermediates here, could you describe what you mean? I've got the stock 44 choco, 43 select pro, and two weed fins for my Blast 145 and I'm wondering what an upright fin like that would do vs. a swept fin.

In a nutshell (plenty exceptions and distinctions to make) an upright fin gains upwind performance, power, and speed. You do loose maneuverability, and maybe some comfort, but who cares if you are in light/moderate conditions with no swells ...

Grantmac: The RRD FSW 85 in Fang 30/Falcon 30 + Point-7 ACX 6.0 configuration works great as a very rough water slalom-ish thingy. 20-25 knots in swell and chop, just stay on its tail and it flies! Very much fun and it can keep up surprisingly well with more dedicated boards. Ultimately it does not, and in some conditions (e.g. long swell with little chop) it feels actually less stable than a slalom board because the rails slow it down and make it "catch". Of course I mostly use the RRD in 4.7-5.3 conditions with Point-7 Spy sails, and a single Maui Ultra Fin X-wave 25. That is its proper regimen. To keep the RRD FSW out of trouble I am getting an AC 88L/60 wide Modena for 6.0-6.8. It takes the place of a venerable Exocet 95L/62. Both on a Phoenix 33.

Upright vs swept: Falcon 30 vs X-wave 25 is a good example. The Falcon jibes wonderfully, but it goes without saying that it is not really the fin to play around in swell with.

Having a selection of boards is about maximising your days on the water, with the ability to cover different wind and water conditions. For me, that means a dedicated wave board, (82 litres), a free ride/freewave crossover board (90 litres), the fox 105, and a tabou rocket 125 free race. With this setup I can sail most conditions that I encounter as long as there are whitecaps.

It sounds to me like the fox 105 might not be the ideal board for you at the moment (although I find mine awesome). It is not a board suited for light winds, but rather medium to strong wind blasting in messy water is where it comes into it own.

The dyno can also play a bit of a similar role, but is also happy jumping on the way out and riding waves on the way in.

So, I'd suggest by swapping one of them - depending on whether you want the broad range of the dyno or the speed thrill of the fox, and finding a bigger freeride board to cover light wind days.