Forums > Windsurfing   Gps and Speed talk

check the vid and post a comment

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Created by eastcoast > 9 months ago, 30 Aug 2009
eastcoast
94 posts
30 Aug 2009 2:01AM
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hi folks,
threw the ca sp44 and koncept 5.8 with lw/mcd sym 23 down a speed course for the first time in west kirby (england)
please watch and tell me what you think,

1. the 5.8 (08) is rigged on a 100% ka sails rdm, bottom 2 cams are rdm top std the bottom 2 have spacers (ka) in the packet there were large and small i would say 6mm and 2mm i have spaced each with 2 large spacers 12mm when rotating the sail i sometimes have to click the final shape in so i would say i have spaced as much as poss top cam no spacers, i downhauled to full 430 and a touch over till the 4th panel from the bottom got that diagonal twist and the batten above started to 'relax' outhaul 0-negative......how does the sail look? one of the locals claimed i needed more downhaul but i felt (to the 5.8 rigging guide) i had gone to the extreme setting and did test the downhaul prior but felt the sail was loosing shape and looked too flat so i didnt.

2. technique... feel free to take the mick but im new to speed on new kit and know i wasnt as locked in as i could of been

first proper outing on speed kit down a broad course
wind gusting up to 30, angle 130
5x 10 sec average 35.24
peak 36.54


eastcoast
94 posts
30 Aug 2009 2:11AM
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not sure if the paste and copy thing has worked???
if not youtube and
speed run 1 ka sails
speed run 2 ka sails

you should find it

cheers for looking

icesurf
QLD, 113 posts
30 Aug 2009 8:06AM
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Here's a few things.

1/ By the photo your Harness seems to be riding too high, looks like a chest harness position from the 80's.



2/ Your Boom may be too high, caused by the chest harness effect, try lower.

3/ Likely not critical, the recommended mast for the KA Koncept 5.8m is SDM.

eastcoast
94 posts
30 Aug 2009 7:30AM
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hi thanks for the reply,
the harness is a brand new 'north cross air' 09 waist harness, basically i did a training day and went through some technique i found i could hold the rig more stable with the waist, and i was running my boom too low so highered it.

lao shi
SA, 1313 posts
30 Aug 2009 11:51AM
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Those are very respectable speeds for a first speed strip outing.
I run a 5.8 07 koncept on a powerex 85% rdm on skinny cams. I downhaul it to spec but run negative outhaul such that the sail touches the back harness line. I have found that this gives me an extra knot or two over the standard outhaul when going broad. My feeling is that the 5.8 on the rdm sets softer than on sdm (used to use a pryde X3 till I snapped it) but it allows for greater top end. (I have got a low 37 on a JPslalomII84l and a 29cm 45 degree fin)

You will also need to try varying the board trim through mast track position (trial and error by small amounts). You are very lucky to have such close video footage for review.

Seat harness allows better leverage or try a weight jacket?

Lastly look how close the top guys go to the bank the flatter the water the faster you will go but be careful.

hardie
WA, 4099 posts
30 Aug 2009 1:21PM
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Awesome spot, not technically adept to comment

eastcoast
94 posts
30 Aug 2009 7:01PM
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thanks lao,
sounds like i set the sail ok..similar to yourself, the batten touches the boom but maybe not as extreme as the harness line....il have a play with that next time. when watching the vid the top of the sail seems to be exhausting nicely so i feel i downhauled ok, it felt nice.

rightly or wrongly i didnt space the top cam or tighten the batten thinking this would help the twist, when downhauling i slowly pull watching the leech as i do and notice that batten releasing at 429 giving the diagonal below...if i space/add tension i thought this would effect that??

the one thing i did do is play around with the mast track, started bang on the middle, then noticed a guy same weight, board, and sail size he had his right back (going alot faster) so i knocked mine back 10mm did a run then another 10 then another. i did my fastest when it was back but not as far as the other guy.

also going close is fine but its rare to see wk like in ur pic...people walk round the lake walking dogs etc, in fact a dog nearly got cut in half on fri!

kato
VIC, 3431 posts
30 Aug 2009 9:27PM
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Try this, the sail looked pretty good but a bit hard to check on how much camber you have on the two battens above and below the boom. Lose the waist harness for speed sailing and save it for the waves, you,ll go faster and be more in control. From the video it looked like the rig wasn,t raked back far enough and the trim of the board too flat. ie not sitting on the tail. Also check with your local speedies Hope this helps

eastcoast
94 posts
30 Aug 2009 7:53PM
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thanks kato,
agreed with the stance, forgot the seat harness rushing to pack so its coming next time!
am i on the right track with the theory of the top cam/batten and not putting shape into it?

kato
VIC, 3431 posts
30 Aug 2009 11:47PM
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eastcoast said...

thanks kato,
agreed with the stance, forgot the seat harness rushing to pack so its coming next time!
am i on the right track with the theory of the top cam/batten and not putting shape into it?


Yes,just enough to take out the wrinkles, too much and it will shudder

eastcoast
94 posts
30 Aug 2009 10:41PM
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thanks,
wind is looking good for this weekend again so i will be trying the new tweaks!

a daft question no doubt but i have been trawling the web for the last hour or so trying to find a weight jacket, nothing specific to windsurfing came up just 'fitness' weight jackets so im asuming thats what people wear??? i would of thought water absorbtion is a facter? is there a make recomended?? im looking for one that carrys the weight high up,

cheers

izaak
TAS, 1991 posts
31 Aug 2009 8:15AM
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KA make weight vests look on there site for price

kato
VIC, 3431 posts
31 Aug 2009 8:26PM
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Most of us have either made own from life jackets/impact vests. Not sure that Ka has any left, they didn,t sell very many. Make very sure that they float with you in it

mathew
QLD, 2054 posts
1 Sep 2009 11:11AM
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Easty, what is your body weight? Generally speaking, lighter guys generally do better with having a bit more downhaul that heavier guys. Maybe you could rig it, then post a few photo's at various angles...

Relatedly, dont try to "go big" to keep up with other guys -> Kato's comment on rake is on the money - if your sail is too big for the conditions, you may find that you cant get the rig onto the deck, you will be lifted onto your toes and you will sheet out.


For jackets, I found that "weight vest" (rather than "weight jacket") is a better term to search for as it returns more results, albeit not necessarily suitable for what we need. I currently use (thanks to Tom Chalko) a modified impact vest from the local surf shop -> just slit-open the back of the vest, insert sheets of lead, then add some velcro to close the slit.

eastcoast
94 posts
5 Sep 2009 10:24PM
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thanks for the responses guys,
thought i would post a report of latest session,

west kirby gusting 35knots angle 135. sp44 ka 5.8 (set up same as week before)

this session was to be a tuning one, i set up the sail as per last week and put a knot on my pb first run bearing in mind it was 5kts+ windier it was expected. firstly binned the waist and put the seat harness on definatley felt i could rake the rig back more and the foot of the sail was touching the footstraps, when gusts hit i wasnt being pulled up (as much ;)
even tho it was windier it was broader and felt underpowered so backed the downhaul of 10mm and negative o/h and put 38.5 on the dial,
during the later afternoon i put the boom up nearly 2 inches and slowly pulled the mast track back in 10mm increments then hit 39.9kts sweet!
shame i didnt put the boom up earlier also idiot free riders were gybing on the wall and after 3 near misses inc one vv close call i had to call it a day :(
also the glassy water of wk has gone, something to do with the new wall so rolling chop of around 200mm is now present.

wkcwarrior
371 posts
6 Sep 2009 12:49AM
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lao shi said...

Those are very respectable speeds for a first speed strip outing.
I run a 5.8 07 koncept on a powerex 85% rdm on skinny cams. I downhaul it to spec but run negative outhaul such that the sail touches the back harness line. I have found that this gives me an extra knot or two over the standard outhaul when going broad. My feeling is that the 5.8 on the rdm sets softer than on sdm (used to use a pryde X3 till I snapped it) but it allows for greater top end. (I have got a low 37 on a JPslalomII84l and a 29cm 45 degree fin)

You will also need to try varying the board trim through mast track position (trial and error by small amounts). You are very lucky to have such close video footage for review.

Seat harness allows better leverage or try a weight jacket?

Lastly look how close the top guys go to the bank the flatter the water the faster you will go but be careful.



HOW DEEP IS THERE, HALF METER OF GROUND ???

eastcoast
94 posts
6 Sep 2009 2:47AM
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most of the lake is chest height, shame the course isnt as flat as the above pic...only sailed it once before the wall was repaired...awesome! seems the boulders on the estuary side are now disturbing the airflow, the speedies recon once some silts been dumped they'l smoothen out....who knows?? really hope so

lao shi
SA, 1313 posts
6 Sep 2009 11:47AM
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Well done on the excellent improvements, eastcoast.
So close to the magic 40.

NotWal
QLD, 7428 posts
6 Sep 2009 3:18PM
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wkcwarrior said...

lao shi said...

Those are very respectable speeds for a first speed strip outing.
I run a 5.8 07 koncept on a powerex 85% rdm on skinny cams. I downhaul it to spec but run negative outhaul such that the sail touches the back harness line. I have found that this gives me an extra knot or two over the standard outhaul when going broad. My feeling is that the 5.8 on the rdm sets softer than on sdm (used to use a pryde X3 till I snapped it) but it allows for greater top end. (I have got a low 37 on a JPslalomII84l and a 29cm 45 degree fin)

You will also need to try varying the board trim through mast track position (trial and error by small amounts). You are very lucky to have such close video footage for review.

Seat harness allows better leverage or try a weight jacket?

Lastly look how close the top guys go to the bank the flatter the water the faster you will go but be careful.



HOW DEEP IS THERE, HALF METER OF GROUND ???


That's just dangerous. If he broke a harness line he would possibly kill himself. He must be a kiter at heart :)

OPH
128 posts
6 Sep 2009 7:47PM
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Stevie Thorp - Kiter - nah, Big wave sailor and GP Moto Racer.

www.stevethorp.co.uk/

Steve grounded the fin a millisecond later, and went over the bars at 40kts!

Following the wall refurb and resultant loss or reduction in laminar wind flow and an increase in turbulent wind flow over the wall, a 5m wide width strip from the wall out into the lake is now prone to turbulent windlfow, resulting in loss of power and drive in the lower portion of the sail. Speed are down by 2 kts typically!

eastcoast
94 posts
6 Sep 2009 11:33PM
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hey h,
2 knots slower??
mean to say i would of hit low 40's?????
bloody refurb :(

OPH
128 posts
7 Sep 2009 1:13AM
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yeah mate no more magic carpet ride. It's either

1. sail close to the wall in the flatter water but in turbulent wind flow or,
2. sail about 20 feet out where the laminar flow re-attaches but then you're into heavy chop.

Longer lines, higher boom and use the next size sail up to what you would normally use for a given wind strength.

However when high tides are about 8.9m, not quite enough to breach the wall, as with Friday, but sufficiently higher enough to cover the boulders up to wall top level, this allowed a better windflow and helped to maintain laminar windflow over the wall off the sea surface

On Friday even though the wind eased off a tad to 22-25kts around the high tide time, speeds were maintained with less wind when the tide was out, and the wind was 5kts stronger. The heavy rolling chop also backed off too.

The excessive rolling chop, on inspection appears to be instigated along the northern wall, where the boulders are a good 1-2 feet higher than pre wall refurb. Many of the upper boulders protrude 6-12 inches above wall height. By shear coincidence the wind flow was disturbed in such a manner that the turbulent rotors were hitting the water immediately behind the wall from more of a angle from the north, this the rolling chop was more prononced higher up the speed course.

Solution:

remove the upper boulders, infill the gaps with concrete (marine grade) forming a gentle slope to the top of the wall from the estuary bed.

Effective wall length 900m
Volume of concrete required 1500m cubed
Cost £300 / metre cubed + labour (15-20 speedies over a weekend)

Job done - return of the magic carpet ride.

OPH
128 posts
7 Sep 2009 1:19AM
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The job could be done cheaper if the "ramp" or "apron" was made up of progressively smaller boulders working away from the existing boulder wall. Then much less volume of concrete would be required to finish the ramp, effectively just infill and smooth over would be required.

OPH
128 posts
7 Sep 2009 1:29AM
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The wind was suffiiciently strong enough in the better gusts, and from a broad direction about 135-140 degrees for me to have picked off a 42kt avg, I struggled to get a 40.27 avg. Everyone who normally hit 40+ with ease that sail regularly at WK did n't even make 39's, all reporting a lack of drive in the kit and a draggy feel to the rig.

Think about it.

The main power band in the sail is .. a couple of feet either side of the boom. If the lower portion is now subject to turbulent windflow, the sail will be less powerful, less drive and feel more draggy.

eastcoast
94 posts
7 Sep 2009 4:05AM
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h very interesting read regarding the wall,

question, why wasnt more thinking done at the design stage by the contractor?

secondly whats the chances of anything being done to rectify it? i imagine fairly slim - i mean its not like the lake brings hundreds of speedsailors were talking a select small group and the likes of the free riders/stylers boats etc dont really have much impact on.
is the sailing club council owned or private? if at £14 a head and 40 people sail (for a week day eg last fri) thats £560, over a week its gonna pull a tidy sum of cash! unless a boycott they dont have a vestive interest in doing anything about it.

is there any millionaire speedsailors out there willing to donate to good cause? :)

so in a nut shell your saying the wall idealy wants extending out a touch at the bottom and smoothing over making the gradiant more 'gradual'

hardie
WA, 4099 posts
7 Sep 2009 7:28AM
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Hey why don'r t you guys enter a Brit team in our gpsteamchallenge.com.au?

izaak
TAS, 1991 posts
7 Sep 2009 10:10AM
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becareful what you say now hardie they do have some really quick guys !

Chipmunk
33 posts
7 Sep 2009 6:01PM
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Mike Pacey Time to hang the wetsuit up

God No. only 50 .Time to start again where’s the ibuprofen ?

West Kirby 3rd September 2009

Nice to see some old faces and new ones its been 15 years since I had a go down the wall so it was a good day for ME to get a top speed of 39.88 knots was great and a good starting point to improve from. 40 + next time

I should have gone out in the stronger winds but I was pretty nervous the big thing with GPS is you set your on goals

still had some VX2 Sails in the garage and my trusty Bic Vivace 270 which I recorded over 41 knots @ 500m West Kirby in 1995 before my accident

But I did think I would need a newer board so off to Robin Hood Watersports where they had a JP 69 small slalom board and it looks good to me

OPH
128 posts
7 Sep 2009 6:31PM
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@ EC

Design ? lol Wirral Borough Council's Budget only stretched to refurb the collapsing wall and not to enhance the windflow for us lot. There main concerns regarding design would be somewhere along the lines of "make the wall stronger" and less prone to sea and wave errosion, in order to avoid spending another 750k a few years down the line.

Mother nature will take her course and redress the balance, wind does not take too kindly to obstructions! Give it a few autumn /winter storms and the silt / sand deposits will return and restore the less turbulent windflow. I cannot say laminar as we never really had proper laminar flow that the guys/gals get at the PiT/Brace/Ray/VK/GC etc.

@ Hardie.


Took the words right out of my mouth mate. I was going to approach you towards the end of the year to get a few UK / Eire Teams set up for 2010. Thats if you are happy about seeing another sporting trophy winging its' way over here

You guys have a fantastic spirit of competition and probably the best forum going.
The GPSTC excels in every way, I'm sure many UK and Eire speedies would be chuffed to be part of such a great global stadium. Thanks for the invite and all the hard work you guys have put in to the speedscene.

eastcoast
94 posts
8 Sep 2009 3:53PM
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h...750k?? i should of put a quote in!

some uk teams sounds fun, gonna have to get faster so i get on a good one!

sailquik
VIC, 6141 posts
8 Sep 2009 11:58PM
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Hi Alex,

I would suggest you try rigging that sail on a 70% or 100% KA SDM mast is you can get your hands on one. Use the standard cams with maybe a spacer on the bottom two.

I tested the 09 Koncept a lot on RDM masts and definitely think it goes better on the more flex top SDM masts. Gets better shape and drive down low and lays off smoother in the top. SDM mast gives a better range as well. The 5m and 4.4m Koncepts have a different cut and luff curve specifically designed for the RDM mast and definitely work better on RDM's. The 5.8m is optimised for the SDM mast.



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"check the vid and post a comment" started by eastcoast