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Introducing mXr-windsurfing's "Rockstar" shapes

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Created by Serge Beumer > 9 months ago, 14 Apr 2011
Serge Beumer
11 posts
14 Apr 2011 6:12PM
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Hi guys,

Here the first view on the mXr-windsurfing bottom shapes for the 46.5 and 54 "Rockstar" boards by Martin van Meurs and Ron van den Berg.


Cheers,

Serge Beumer
The Netherlands

hardie
WA, 4077 posts
14 Apr 2011 8:04PM
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Explain?

nebbian
WA, 6277 posts
14 Apr 2011 8:41PM
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Wow that's an interesting idea.

I guess they're after a bit more stability?

If I'm thinking right it's a set of steps, so if you were going at speed on perfectly flat water the front step, the middle step and the tail of the board would all be just submerged, while just behind each step would be dry.

Bags not shaping and glassing it

Te Hau
479 posts
15 Apr 2011 7:15AM
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It looks a bit like the 'Stinger' idea from the late 80s early 90's.
I think it was Graham Allen (of White Lite fame) who was playing with it.
Bottom shapes seem to get pretty elaborate in these days of design driven by advertising men.
I wonder if they work that much better than a simple bottom shape.
The fastest GPS speeds are still on pretty straightforward flat/vee bottoms.
K.I.S.S.

Crash Landing
NSW, 1173 posts
15 Apr 2011 9:21AM
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Mistral did this back in the 90's with their race/slalom boards that were bright orange. The idea was as you got planning the boards planning flat could more back and you had less surface area in the water... (I think).

sick_em_rex
NSW, 1598 posts
15 Apr 2011 9:27AM
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Anyone in Sydney interested in this concept should stop in at WindSurfNSnow and ask to have a look at Bruce McKee's old speed needles from the 80's. He was a guy I worked with at Bombora back then and he was the man responsible for the Capricorn and a couple of other boards. He made his needles with a pitch fork nose and a very stepped hull. He modelled them on the stepped hulls of F1 boats and sea planes, the idea being that there was the most minimal amount of board being in the water to create drag. F1 boats use that hull shape to get up on the plane very quickly so it must work in some way. The boards look amazing and were a lot of fun to ride. We even had them going in Narrabeen Lake back then!
Everything old is new again......it's just made from carbon now

lelos12345
NSW, 453 posts
15 Apr 2011 11:13AM
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bagging aside... that its all been done before ... Theres been very little advance in board speed at the top end for quite a while.

I give credit to anyone who thinks outside the square even if it has been done before... I'm sure they have done it better.

these projects take a lot of invested time effort passion money I say lets be positive as someone is taking a seriuos look at taking our beloved sport of speed maybe to the next level !!

Grafix and name thats another Post



Roo
765 posts
15 Apr 2011 9:26AM
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Can't wait to see the P0rnstar...it will be the one that does tricks!

ka43
NSW, 3062 posts
15 Apr 2011 11:56AM
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I reckon its great. Back in the day there were a few guys thinking outside the square. As Rexy mentioned Bruce McKee, there was Mike Davis with his ski tail design, other Bombora's with different bottom shapes, and lots of custom shapers that tried some prett exotic ideas. It was all fun.
tail cutouts of today are heading back in this direction. Less wetted surface was the aim.
Remember everyone poo-pooed monofilm, cambers etc at first.
You never know unless you have a go

choco
SA, 3995 posts
15 Apr 2011 4:09PM
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Don't think the design is going to be any faster than what is around today but it is an easier board(from what i've heard) to sail FASTER for the average sailor.

yoyo
WA, 1646 posts
15 Apr 2011 3:09PM
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Martin V M talked about the board some time back on gps-ss. It is nice how the deck graphics intergrate with the wingers/steps. Even if it had a flat bottom it would probably be a very fast and desirable bit of speed kit.






session_date Friday, February 04, 2011
Spot Haringvliet, Netherlands
Board Infinity rockstar 46, 2011
Sail Point-7 AC1 2K11 5.0, 2011
Fin C3 SLINGSHOT 21
GPS type Navi GT-31


Average speed 43.94 knots ( 44.64 44.22 43.74 43.7 43.41 )
Max. 2 sec. (software) 47 knots
100 m run 46.51 knots
250 m run 44.32 knots
500 m run 40.02 knots
Nautical mile 5.43 knots
1 hour 2.19 knots
Alpha racing 8.12 knots
Distance 14 km
Duration 00:34:00
Windspeed 0 - 0 knots
Wind direction W ( 270)


When the day started and I would have been happy to even be able to do some test runs. the last two days I could hardly walk due to extreme back problems and doubted whether it would be wise to do a surf session but the forecast looked too good to not at least give it a try. At the end of the day the guys nearly needed to carry me into the car. My back and my hip hurt even more but at least I then knew the new gear works!!! Yiihhaarrrr.

The first apporved Infinity board is a fact. It's new, it's fresh, it's different. This might sound cocky but Ron and I created something I am really proud off. The board doesn't look like any board now available, is self balancing and sails over chop as if there is no chop. It might not be faster for top surfers but is at least just as fast and it will help windsurfers of different levels to go faster more easily. the design is more a freerace design than a pure race design but it's a killer speedwise. The design objective was exactly the same as the Slingshot design objective: widen the range in which gear can be used. I am sure in lighter windspeeds and on bigger boards the differences will get even bigger. OK, so much for bragging, I hope you forgive me as I am stoked about the day. This must be a crippled man's world Record haha.

Jurjen pushed me and overtook me half way during the session. I needed to sit and watch for 15 minutes after every painful run and saw just how balanced his set looked and how stylish he was conquering the difficult conditions. I was a bit underpowered and just when I acepted the fact he beat me the wind swung back a little and increased just enough to make the 5.0 work. Kudos to you Jurjen, without this lucky change you would have taken the day.

When the wind swung round a little at the end of the afternoon I already could hardly walk, but I wanted to try and get the day victory in. the Point 7 5.0 (yeah baby) started to deliver the power I needed. It's really extremely well balanced and I am totally stoked about the performane of the sail. The leech opens up a lot and I am sure in the right windrange it will deliver the goods for extreme topspeeds. The last two runs were nearly just as fast topspeedwise and on any other day I would have pushed for 90km/h as I felt this was possible. But my body just quit working so I had to stop. Still a happy man and speedwise a great way to start my sailing year...


It seems since Martin wrote the above comments he has moved to Blackdiamond fins after many years being with Boogie on C3. He also recently dislocated his shoulder. He certainly has been in the wars lately. Going too fast with narrow strap positions?

slowboat
WA, 548 posts
15 Apr 2011 3:10PM
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Roo said...

Can't wait to see the P0rnstar...it will be the one that does tricks!


At the hospital: Doctor: "So MrX, how did you come to get that board stuck in there?"
MrX: "honest, I had a crash"

Ian K
WA, 4039 posts
15 Apr 2011 5:47PM
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Always wondered how much drag is associated with water release off the trailing edge. This design has 3 training edges so maybe not much? We know soft rails are slower but how sharp do edges have to be to release water with minimum drag? There must be a radius of curvature beyond which no more improvement is worth chasing? Maybe it's about 1 mm?

The other thing I've wondered about is the optimum rocker for minimum drag. Flat is a pretty random hydrodynamic shape, but I can see that a hollow rocker on a non-stepped hull is no good as it will be difficult to stop the nose sticking. But with 3 planing surfaces slightly hollow rockers approaching the trailing edges won't cause this problem. A flat rocker line generates most of its lift near the front of the wet area. But if the rocker is hollow the lift can be spread out a bit. Is that better? The wetted area will be smaller with an increasing angle of attack , but there'd be an optimum trade off between induced drag and wetted area. I'll have a guess and say just a slightly hollow rocker would be best.

(I've seen 2 definitions of induced drag but I'm thinking of the extra drag a barefoot water skier must have because the small planing areas of his feet have to be at a huge angle of attack to get the required vertical lift.)

It does look as though the fin and footstrap placements are traditional. So maybe that front step is more for trim than for significant lift. If the hull lift was forward you'd have to get the weight a bit forward to balance the system - fin, footstaps and mast base would be all have to be maybe a few inches to a foot forward.



slowboat
WA, 548 posts
15 Apr 2011 9:07PM
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Ian K said...

Always wondered how much drag is associated with water release off the trailing edge.


The drag can either be caused by surface friction, or by induced drag. Induced drag is basically the energy transferred out the back in the wake. So the bigger the wake, the greater the energy to make it, and the greater the induced drag.

I think the fastest way to sail is with no board in the water most of the time. The lowest drag setup is minimal surface area for the minimum time. Keep in mind the fin needs to stay wet enough of the time to remain functional overall.

keef
NSW, 2015 posts
15 Apr 2011 11:51PM
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yoyo said...

Martin V M talked about the board some time back on gps-ss. It is nice how the deck graphics intergrate with the wingers/steps. Even if it had a flat bottom it would probably be a very fast and desirable bit of speed kit.







martin great professional job especially the graphics top and bottom ,47 2sec Say's it all i like how parallel the rails are between the cutouts, as a matter of interest how much V is there at the front cut out for eg, if you put a strait edge flat on one side what the measurement on the other, i can see why it eats chop job well done ,

Ian K
WA, 4039 posts
16 Apr 2011 5:53AM
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keef said...
if you put a strait edge flat on one side what the measurement on the other, i can see why it eats chop job well done ,


Hard to tell with a ruler on the screen, but I'd say it's the second peanut board to hit the water Keef! Probably also gybes like a dream. I can see now on Yoyo's post that the rocker in front of each step is flat. The first step probably stays dry most of the time in flat water?

choco
SA, 3995 posts
16 Apr 2011 7:27AM
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At least they are built out of carbon, look like a work of art

keef
NSW, 2015 posts
16 Apr 2011 8:25AM
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Ian K said...

keef said...
if you put a strait edge flat on one side what the measurement on the other, i can see why it eats chop job well done ,


Hard to tell with a ruler on the screen, but I'd say it's the second peanut board to hit the water Keef!


well mabe for 2011 but ive got another 3 remember, i was going to say it looks like a peanut but i wouldnt want any one to think im a smart ass
At least they are built out of carbon, look like a work of art
choko theres probably no carbon, thats a decal

mvm
49 posts
18 Apr 2011 9:38PM
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Hi guys,

Thanks for showing iinterest. I still sail with Boogies fins once and a while, for instance with the great slingshot, but I just not do not sail exclusively with his fins anymore. Apart from starting up a boardbrand together with Ron van den Berg, we also want to start building fins. I'd obviously like to get Boogie in as designer for some of our fins, but I respect and understand the fact he wants to focus on C3.

The steps give us the freedom to work with multiple rockerlines. The boards are meant to ride on the back step and the tail, but for light wind configurations are possible in which the boards ride on the front section as well in windlulls. Our tests up till now clearly show we're on the right track. Gybing is a dream with tons of grip, the straight section helps to drive the board upwind at a high angle and they also secure a relaxed ride as the board has got less tendency to bounce.

Chris Lockwood started working on relatively straight mid sections and once I noticed just how well his designs settled regarding trim angle, it made me think just how far we could take this. With the support of the back step, the board sets itself nicely on the tail making it super easy to find the right trimming angle for high speed runs. I beleive we found a nice balance in the outline and rockerlines.

We're now working on light and medium wind designs. All designs are focussed on the ease of use for an average rider. Especially lighter, shorter but also less experienced riders often have difficulties keepung the right trimming angle on chop. Time will tell if we succeeeded, but so far I am happy with the first comparison tests.



keef
NSW, 2015 posts
20 Apr 2011 9:34AM
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mvm said...

Hi guys,



, the straight section helps to drive the board upwind at a high angle and they also secure a relaxed ride as the board has got less tendency to bounce.

I beleive we found a nice balance in the outline and rockerlines.

We're now working on light and medium wind designs.


MVM can you come up with a GPS challenge all rounder for moderate winds , some thing that will constantly do 32 to 35knts in 20 knts of wind a 25NM and a 22 alpha, there are heaps of boards out there that are fast, but when it comes jibing they bog down and start dropping off the plane with the slightest of wind variation
i have a couple of boards with the step cutouts too keep the rails parallel which are needed for a good NM and a clean release when sailing off the wind
Ive been looking at your board and I'm not sure about the multiple rocker lines, i can see one continuous rocker concave from tail to nose, then there is two massive v's between the steps that can cause side wash and drag correct me if im wrong


Ian K
WA, 4039 posts
20 Apr 2011 1:33PM
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It's interesting that you confirm that it gybes well Martin. The two smoothest gybing boards I've had are the CA SP50 and the Naish Hybrid - both fairly straight in outline (plan view) between mast track and footstraps. Keef reports his banana board gybes very well also, very straight if not hollow in outline.

When you put a board like this on edge that equals a long and shallow groove in the water taking in a fair bit of rocker line. So it makes sense to me that it makes for a nice stable turn.

Snow skis turn best with a bit of sidecut also. I've noticed the latest Fanatic quad waveboards are getting straighter in outline between mast track and footstraps. If this is a fair generalisation how come it's not commonly acknowledged? Or maybe it's just the way I sail?

When are you going to put up a picture of your latest creation Keef?

keef
NSW, 2015 posts
20 Apr 2011 4:34PM
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[b]Ian K said...
When are you going to put up a picture of your latest creation Keef?


Ian shrrrrrrrrrr i'm trying to keep it a secret

mvm
49 posts
20 Apr 2011 5:27PM
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Funny you are working on straighter mid sections as well Keef. I notice your board is still a little curved? We also place our front winger more forward as we want to distribute the power more towards the mastfoot.

I dare say the rockstar boards are the best gybing speed/slalomboards I ever sailed. Ron and I are now working on wider speed/slalomboards which are even more radical in outline and steps. So far they prove to be working quite nicely. I finished second last week in a choppy session in which others were riding 80 litre boards while I was riding a 110 litre board which is partially hollow in the outline like Ian K suggested. I am sure with any other modern day medium light wind slalomboard I would have never stood a chance as it would have just bounced around the water in those conditions. The same board already planes in very light winds and is blistering fast in those conditions as another session proved. I am far from recovered from a dislocated shoulder and needed to take things easy up till now, but it seems I am recovering fast now so the test phase is picking up speed.

Regarding the rockerlines I like to look at it that way as our solutions give the rider the freedom to use various rockerlines depending on the board angle. Arguably you could also say the same about conventiional boards with increasing V towards the front section but the response of those boards is completely different as our boards lock themselves at a given angle. We are also working on roundbottom shapes running into convace, running into roundbottom, running into V, triple concaves running into quattro, running into cinquo etcetera.

Our rockerlines differ completely from what's now being used. Modernday medium wind slalomboards have got 150cm points of up to 2.8cm at 150cm from the back. That's not needed at all regarding to us. It also makes getting up to the plane more complicated and technical for most riders.

I had some radical ideas for years, but was being held back by the brands that sponsored me. Now we're free to do as we please. When I was still working closely together with Boogiie we had some out of the box talks which were inspiring. Together with my test buddies Serge Beumer and Marcel Braas I also shared ideas and things evolved from there. When I first started talking with Ron about the brand I told him to forget about shaping boards and start looking at shaping scultpures. I wanted us to completely break free from conventions and the route imposed on us by the PWA. Effectively this route leads us towards boards which are suited only for super heavy riders who sail ridiculously large sails, at least that's our opinion.

Mattias Jildestad came up with a great constructer and now we're on our way to produce the frst boards.

mvm
49 posts
20 Apr 2011 6:38PM
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Hollow outline behind front step. One of the details we've been testing lately.

keef
NSW, 2015 posts
21 Apr 2011 11:46AM
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MVM I'm afraid im not a great shaper but i seem to come up with what suits my style of riding , im not trying to get 40knts+ from this board ( got an other one for that), my aim is to have one board for the GPS team challenge with a sail range of 4.5 to 7.5 with out having to stick on a huge fin for the bigger sails
here is the boards first time on the water with a custom weedie(not much wind) and the weedie is dam small gpsteamchallenge.com.au/sailor_session/show?date=2011-03-24&team=34,
the board is a bit deceiving looking from the bottom ,(different outline profile to the bottom) it almost has 2 rocker lines from the nose to the front strap ( a chine ) great for chop and helps jibing, you will notice the foot area's are recessed by 30ml that enables you to carry more volume in the tail and have a bit more stability in higher winds
(foot recesses)

keef
NSW, 2015 posts
21 Apr 2011 12:02PM
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here is a different shot of the board , you will notice the volume and width is further back( but different to the bottom), you will also notice the box isn't glassed over, the reason is last June i smashed the back of the fin box out of my ca55 so now it can be repaired from the inside of the box with some knee-it strait away , i also beefed up the back of the box with some 10ml divinycell for insurance

yoyo
WA, 1646 posts
21 Apr 2011 11:23AM
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Interesting board. Why did you have the winger in front of the front foot and not behind?

keef
NSW, 2015 posts
21 Apr 2011 4:35PM
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yoyo said...

Interesting board. Why did you have the winger in front of the front foot and not behind?


yoyo the wingers are apart of the foot recess's , from memory there about 30ml deep so your heel is low to the water, it keeps your foot a bit inboard but on the rail, as well as trying to reduce the water plash from hitting your heal especially the back foot, what i have found on boards with foot recesses is when you take your foot out to jibe your foot has the tendency to catch the splash seeing it is so close to the water and im sure the wingers help a bit

mvm
49 posts
21 Apr 2011 4:06PM
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Hi Keef,

You mention you're not much of a shaper, but I think your shape is looking great. In our case, Ron van den Berg is the genius who builds the boards.Great you show your work!

mvm
49 posts
17 May 2011 3:13AM
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yoyo
WA, 1646 posts
17 May 2011 11:23AM
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Great graphics.



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Forums > Windsurfing   Gps and Speed talk


"Introducing mXr-windsurfing's "Rockstar" shapes" started by Serge Beumer