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agrelon
8th February 2010, 01:06 PM
Hi all,

I've just bought a 2006 JP Super X 106l and was blown away on my first outing by it's speed and acceleration.

I had the foot-straps in the outboard setting but only on the 3rd (out of 4) most back setting, and can therefore still move both straps about 2cm further back.

Does moving the straps further back generally increase maximum speed?

I would have imagined so as there would be more lift on the front of the board and less wetted surface area....

Any comments?

mac33
8th February 2010, 11:43 PM
at your weight 54kg, moving straps to very back position would produce too much board lift, especially in stronger wind. i am another 12kg heavier, i have my backstraps as far forward as possible.

this helps to stop the board from taking off in gusts.

ask different sailors and some will say moving straps back is faster, a few will say moving straps forward is faster.

at my 66kg i try to reduce the lift of board as much as possible.

straps forward,weight in harness forward to nose, smaller fin,lower boom and high hook height all help.

a 5.8m at 54kg is quite large. a 4m + 5m will be faster for you if the wind is decent.

agrelon
9th February 2010, 10:36 AM
Thanks for your advice. I think the same sort of thinking applies for mast track position... further back = more speed but less control due to more lift.

I had a 5.3m until 3 days ago when it got stolen from the place I stored it on the beach... So I'm with a one board and one sail for the moment. I do have a smaller fin though, which I can stick on my board if the wind really picks up to help me gain as much control as possible.

Farlo
9th February 2010, 05:28 PM
JP SX106 has not much power in tail, and is not the most stable in its category. IMHO you will gain very little speed (if any) by moving the straps back. Some shapes work better globally with backward settings because you fly higher over chops. This one has a tendency to take-off already. A smaller fin will have a lot more influence on control and speed.

agrelon
10th February 2010, 09:53 AM
JP SX106 has not much power in tail, and is not the most stable in its category. IMHO you will gain very little speed (if any) by moving the straps back. Some shapes work better globally with backward settings because you fly higher over chops. This one has a tendency to take-off already. A smaller fin will have a lot more influence on control and speed.

Next time I sail I'll try using my smaller fin (~30cm), footstraps completely back and out and mast track slightly back. I think with the smaller fin I should still be able to control the increased lift and might see some gains in top end speed.

Cheers.

iago
26th February 2010, 04:52 PM
perchè parlate di tavole Jp sul sito starboard??


why talk of JP boards on the site starboard?

Unregistered
26th February 2010, 05:16 PM
iago - my thoughts exactly

what about Futura or iSonic ??

agrelon
26th February 2010, 06:17 PM
iago - my thoughts exactly

what about Futura or iSonic ??

Because unfortunately I only have the money to buy second hand equipment and that a JP board was the best thing on offer. Trust me, if I could've gotten a Futura or even an S-type I would have.

As for posting on this forum, it's the best one on the internet for windsurfing info.

sergio_k
26th February 2010, 10:35 PM
I'd like to put in few more comment on foot strap positions /fin size, etc..
mine always all the way back with relativelly large fin, if you have problems/tail lifting,
you have choices: moving mast track forward, smaller or better fin, moving
foot straps forward, specially front ones (makes your stands wider),
all of those things will de-power you set-up but will give you better control,
so final result could be actually a better avg. speed,
as your tecnique improves, you'll be able to move all settings back again.

www.miamiwindsurfer.blogspot.com

agrelon
27th February 2010, 10:24 AM
I'd like to put in few more comment on foot strap positions /fin size, etc..
mine always all the way back with relativelly large fin, if you have problems/tail lifting,
you have choices: moving mast track forward, smaller or better fin, moving
foot straps forward, specially front ones (makes your stands wider),
all of those things will de-power you set-up but will give you better control,
so final result could be actually a better avg. speed,
as your tecnique improves, you'll be able to move all settings back again.

www.miamiwindsurfer.blogspot.com

I found last time I was sailing that even with a 36cm fin for my 5.8m and bft5 wind I could keep the back end quite quiet. My mast track had slipped completely forward and my footstraps were in the 3/4 most forward position.

I had almost exactly the same straight line speed as my friend on an Exocet S-Cross with 6.3m and a 36cm fin so I'm going to try the following to gain the extra bit of speed I need to leave him behind me:

- Mast track middleish/back (and tighter so it doesn't slip forward)
- 4 cams on my sail instead of 2 ( theoretically it can be rigged 3 or 4 but taking out the top one was fine so I tried it)
- All footstraps back 1 knotch so 2nd most back position
- More outhaul (when I got back to the beach I realized mine had come slightly loose...)
- Smaller fin (I'm trying to find a 32cm fin as my 36cm is seriously impeding on my top end. Also, as the guy I'm up against has a 36cm fin and weighs more so generally has bigger sails logically I should have a smaller fin)

I think that with all this I should gain at least 3 knots in top end.

Unregistered
27th February 2010, 06:13 PM
if you already have an AHD 106, did you buy the JP for speed or ??

agrelon
28th February 2010, 10:43 AM
if you already have an AHD 106, did you buy the JP for speed or ??

Bought it because I was looking for a better board. The AHD was not wood construction, quite long and heavier. It only took one run on the JP for me to be sold. The JP is definitely faster as well, to plane and top speed.

Jean-Marc
7th March 2010, 04:32 AM
Agrelon,

I find that for your XS weight, a 36 cm fin is way too large with a 5.8 sail.

Never run that JP but I did use a Starboard Carve 111 with her stock 32 cm fin and a 5.4 m2 sail but the stock fin was way too large. A 26 cm slalom fin was a perfect setup up to 25 knots for my 65 kg, so I surmise the same should be fine with your 54 kg as well. A 36 cm fin was recommended for a 7.4 m2 sail on the Carve 111 BTW, so I'm pretty sure there is something wrong with your fin sizing setup.

Cheers!

JM

agrelon
7th March 2010, 08:39 AM
Agrelon,

I find that for your XS weight, a 36 cm fin is way too large with a 5.8 sail.

Never run that JP but I did use a Starboard Carve 111 with her stock 32 cm fin and a 5.4 m2 sail but the stock fin was way too large. A 26 cm slalom fin was a perfect setup up to 25 knots for my 65 kg, so I surmise the same should be fine with your 54 kg as well. A 36 cm fin was recommended for a 7.4 m2 sail on the Carve 111 BTW, so I'm pretty sure there is something wrong with your fin sizing setup.

Cheers!

JM

High JM, yeah I think so too. Even with the straps completely outboard I had to dig my heels in to keep the board flat. Also, I couldn't initiate carve jibes which was really strange.. but according to the Select-Hydrofoil website that is one symptom of having a too large fin.

I'm trying a 32cm today, I think it should be much better.Just put side by side, my 36cm and the 32cm seem to have an even bigger difference in size than 4cm, and the 32cm is much lighter. I'll post back on how this setup works.

Cheers.

Jean-Marc
11th March 2010, 05:16 AM
Agrelon,

The more I think of your 36 cm fin, the more I find it way too large with a 5.8 sail when overpowered in 6-7 Bft for your 54 kg rider weight.

For illustrative purpose, this is what I'm using with a 5.4 sail in well to over-powered up 20-25 knots of wind (all 4 footstraps outboard and back):
-Hypersonic 105 (77 cm max width/54 cm width OFO): 26 cm slalom fin. A 32 cm slalom fin is too large.
-Carve 111 (63 cm max width/40 cm width OFO): 26 cm slalom fin. A 32 cm freeride fin is too large.
-Kombat 86 (59 cm max width/39 cm width OFO): 24 cm wave fin. A 30 cm freeride fin is too large.

BTW, I'm on Acid 62 + 4.7 m2 wave sail + 20 cm fin in true 6-7 Bft (25-30 knots wind). The stronger the wind, the smallest the gear should be picked up for a light weight rider to still be in 100% control when fully lit in choppy seas. The Carve 111 is for sure too big with a 4.7 sail for me whereas the Kombat 86 is still barely manageable with a 4.2 sail up to 7-8 Bft (2 front straps inboard and front; single rear strap centered and front. All 4 footstraps outboard and back was just impossible to keep sailing the board trimmed flat & fast).

Cheers !

JM

agrelon
11th March 2010, 03:01 PM
Agrelon,

The more I think of your 36 cm fin, the more I find it way too large with a 5.8 sail when overpowered in 6-7 Bft for your 54 kg rider weight.

For illustrative purpose, this is what I'm using with a 5.4 sail in well to over-powered up 20-25 knots of wind (all 4 footstraps outboard and back):
-Hypersonic 105 (77 cm max width/54 cm width OFO): 26 cm slalom fin. A 32 cm slalom fin is too large.
-Carve 111 (63 cm max width/40 cm width OFO): 26 cm slalom fin. A 32 cm freeride fin is too large.
-Kombat 86 (59 cm max width/39 cm width OFO): 24 cm wave fin. A 30 cm freeride fin is too large.

BTW, I'm on Acid 62 + 4.7 m2 wave sail + 20 cm fin in true 6-7 Bft (25-30 knots wind). The stronger the wind, the smallest the gear should be picked up for a light weight rider to still be in 100% control when fully lit in choppy seas. The Carve 111 is for sure too big with a 4.7 sail for me whereas the Kombat 86 is still barely manageable with a 4.2 sail up to 7-8 Bft (2 front straps inboard and front; single rear strap centered and front. All 4 footstraps outboard and back was just impossible to keep sailing the board trimmed flat & fast).

Cheers !

JM

Thanks JM for this answer.

Indeed, a while ago on this forum I was recommended to use super small boards (60-70l) at my weight in high-winds. The problem with my spot (Hong Kong) is that the wind is extremely unstable and gusty. In order to get to a more stable windline, I have to exit the bay and then it's full open water. I much prefer this as the wind is much more stable and you can launch off some great breaking swell.

I've been caught out once or twice even outside of the bay where the wind has dropped to less than planning conditions which is why I'm not opting for anything smaller than 95l for the moment.

I've gotten a 32cm fin for my board which is 63cm wide and when nicely powered up the board is perfectly balanced with the outboard straps, no need to dig my heels in to keep the board flat. I have yet to try this fin out in over powered conditions, but for the moment it's much better than the 36cm.

Thanks for your advice.