orsm

antoine looks like a monster when you see them all standing together

Still find it amazing that these bigger guys are still faster in lighter winds than the light weight sailors, ok they might take a bigger board and sail but someone lighter on smaller kit should be faster.

choco said...

Still find it amazing that these bigger guys are still faster in lighter winds than the light weight sailors, ok they might take a bigger board and sail but someone lighter on smaller kit should be faster.

They can hold a bigger sail down in a more stable position thus taking advantage of the gusts.

SWS said...

choco said...

Still find it amazing that these bigger guys are still faster in lighter winds than the light weight sailors, ok they might take a bigger board and sail but someone lighter on smaller kit should be faster.

They can hold a bigger sail down in a more stable position thus taking advantage of the gusts.

A lot of things going on but I've had a go at a dimensional analysis.

Parasitic drag of the rider goes up with the cross sectional area or the square of rider dimension. Righting moment of the rider goes up with the fourth power of rider dimension. (The weight has gone up with the cube of dimension and the arms are longer to get further outboard).

The counteracting moment of the sail goes up with the area and height of the centre of lift above the deck. ie the sail dimension cubed.

So, balancing moments, we have the cube of the sail dimension going up with the 4th power of rider dimension. Call this equation 1.

The force generated by the sail is proportional to the sail area or the square of the sail dimension.

So taking the 2/3 root of both sides of equation 1. we have sail power going up with the rider's dimension (height) to the power of 2.7 . And the sailor's parasitic drag only goes up with the sailors "height" to the power of 2. So the lift to parasitic drag ratio gets better as the rider gets larger.

What do you reckon? Pretty sure it's a valid analysis. I've thought though it a few times.

A lot of other things going on though. Chunky riders vs. lean riders? signals from the brain to the feet of tall riders? Chop at the short end of the spectrum can be ignored by large riders.

finally! been waiting for such a long time..congrats to him

elmo said...

Respect

Yes, I second that.

Ian K said...

SWS said...

choco said...

Still find it amazing that these bigger guys are still faster in lighter winds than the light weight sailors, ok they might take a bigger board and sail but someone lighter on smaller kit should be faster.

They can hold a bigger sail down in a more stable position thus taking advantage of the gusts.

A lot of things going on but I've had a go at a dimensional analysis.

Parasitic drag of the rider goes up with the cross sectional area or the square of rider dimension. Righting moment of the rider goes up with the fourth power of rider dimension. (The weight has gone up with the cube of dimension and the arms are longer to get further outboard).

The counteracting moment of the sail goes up with the area and height of the centre of lift above the deck. ie the sail dimension cubed.

So, balancing moments, we have the cube of the sail dimension going up with the 4th power of rider dimension. Call this equation 1.

The force generated by the sail is proportional to the sail area or the square of the sail dimension.

So taking the 2/3 root of both sides of equation 1. we have sail power going up with the rider's dimension (height) to the power of 2.7 . And the sailor's parasitic drag only goes up with the sailors "height" to the power of 2. So the lift to parasitic drag ratio gets better as the rider gets larger.

What do you reckon? Pretty sure it's a valid analysis. I've thought though it a few times.

A lot of other things going on though. Chunky riders vs. lean riders? signals from the brain to the feet of tall riders? Chop at the short end of the spectrum can be ignored by large riders.

Good post.

Also, induced drag is inversely proportional to the length of the leading edge of a foil, so induced drag drops as rig height and fin depth increases. If the big guys can carry taller masts and deeper foils they get another benefit.

I've checked the speed of brain-to-limb signals, and there's basically no difference because the speed of the signals is so quick.

Of course, as soon as you move off FW/slalom/speed gear and into the more popular racing formats (hybrids and longboards are something like 150% as popular worldwide) and you start racing in light winds with restricted sail size, lighter sailors get a very good chance and medium weight sailors may dominate.

So a windsurfing ant will always be back of the pack....

Small to medium size windsurfers can be very competitive. The male RSX sailors average around 74kg (using the figures I can find on the net) with highly competitive women around the 55-60kg mark (guessing at Jessica's weight).

Sure, in FW, slalom and speed bigger may be better. But while they are great disciplines, they are NOT all of windsurfing and in fact there are more people racing longboards and hybrids than racing FW and slalom. And I think there's a very high chance that there are more full-time sailors in the Olympic class than in FW.

So without knocking FW and slalom in any way, you can't just say what works in them works for all of the sport, or even all of racing.

Well done Bjorn - nice to have that familiar feeling back again I'm sure.

Well done also to Starboard - a great achievement for their outstanding iSonics.

And a big congrats to Ben Severne - Adelaide boy who has gone on to design sails that can achieve multiple event wins and world championship wins.

da vecta said...

Haircut said...

orsm

antoine looks like a monster when you see them all standing together

That's not a real lighthouse he's holding!

Looks like it takes batteries

Great effort to Dunks and the team at Serverne and Starboard.

da vecta said...

Haircut said...

orsm

antoine looks like a monster when you see them all standing together

That's not a real lighthouse he's holding!

that's a lighthouse?.......I thought he'd won this

The thing is ......

We don't really do much lightwind racing in the PWA. I only used my big board (iSonic 127) in 2 races in Turkey this season and both times I was super overpowered on it. Costa Brava, which I skipped had 1 lightwind day but otherwise there were really no other light wind days this season.


Definitely in lighter winds the lighter sailors have a better chance at closing the gap but in places like Turkey where its flat water the big guys could carry massive sails (ie, using 7.8 in +30 knots) and would go double the speed of smaller guys on smaller sails. It's not really comparable looking at slalom vs Formula/RSX/Hybrids etc because they are all going upwind/downwind and more factors come in to play than just top speed.

Most of the racing we did this season on the PWA was in 20-30 knots whereby most sailors are on 7.8 and 110L boards. In these conditions being +100kg vs 80kg is a massive, massive advantage.

If you want to look at it more scientifically, look at it from a 'Sail Carrying Power' perspective.

SAIL CARRYING POWER =
Righting Moment / Distance between the centre of effort of the sail and the combined lateral resistance of the hull and fin.

Antoine or Bjorn at 100kg would have a sail carrying power of 20% more than someone like Steve Allen at 82kg.

If you have a copy of anything Bethwaite has written you can read more about that (though he also looks at total weight of the hull but slalom gear is so light compared to boats).

SeanAUS120 said...


Antoine or Bjorn at 100kg would have a sail carrying power of 20% more than someone like Steve Allen at 82kg.

How about the guys from 7th to 20th place in Alacati, not really the bulky guys and they manage to be upthere, top 10 quite regularly. Do they sail more in these conditions etc... what's their secret??

SeanAUS120 said...

The thing is ......

We don't really do much lightwind racing in the PWA. I only used my big board (iSonic 127) in 2 races in Turkey this season and both times I was super overpowered on it. Costa Brava, which I skipped had 1 lightwind day but otherwise there were really no other light wind days this season.


Definitely in lighter winds the lighter sailors have a better chance at closing the gap but in places like Turkey where its flat water the big guys could carry massive sails (ie, using 7.8 in +30 knots) and would go double the speed of smaller guys on smaller sails. It's not really comparable looking at slalom vs Formula/RSX/Hybrids etc because they are all going upwind/downwind and more factors come in to play than just top speed.

Most of the racing we did this season on the PWA was in 20-30 knots whereby most sailors are on 7.8 and 110L boards. In these conditions being +100kg vs 80kg is a massive, massive advantage.

If you want to look at it more scientifically, look at it from a 'Sail Carrying Power' perspective.

SAIL CARRYING POWER =
Righting Moment / Distance between the centre of effort of the sail and the combined lateral resistance of the hull and fin.

Antoine or Bjorn at 100kg would have a sail carrying power of 20% more than someone like Steve Allen at 82kg.

If you have a copy of anything Bethwaite has written you can read more about that (though he also looks at total weight of the hull but slalom gear is so light compared to boats).

What about Tatty?

If you watch BD closely in his races, he sails some very good angles. A lot of other blokes spend to much time bearing up, then down before the gybe mark...he does the opposite.

But WTF would I know....