I have been watching graphs from NC sailors yesterday and what strike me was relatively high bottom speed during the gybe / alpha.When speeds during the gybe never dropped below 15 knots.










Can somebody show similar achievements : During the single gybe the speed never dropped below
a) 15 knots
b) 17 knots
c) 20 knots ??!!

-that could be good example of the smoother planing gybe possible
-then interesting will be to know what type of gybe technique is that ( lay down, step, carve etc), how to keep power and speed all the time.
We had already few videos of very nice , fluid gybes performed by our SB sailors, but interesting will be to see how it looks in numbers during this GPSResult analysis.

I was trying to analyse my gybes in real speed last night but couldn't really figure it out.
I felt I'd done some nice ones but they were too wide for an alpha.

I have been looking at today's best sailors KA recording and here how it looks nice 24.88 alpha

Amazingly speed during the gybe dropped to 11.7 knots but recovery was very quick

In RealSpeed you can change the proximity circle size in the division settings to analyse non legal Alphas. Just remember to re-set it after you play!

GPS Action Replay Pro is great for this stuff. It has a "Jibe analysis" menu item in the speed menu that will display a table with minimum speed, radius, and a bunch more for all jibes in a session. Click on a column header to sort by the column like in Excel, and you'll find the minimum speed in your best jibe within a few seconds. A minimum speed of 16 knots is darn good. My best jibes ever are around 12-13 knots. I'd love to see videos with these 16 knot jibes!

I've idly wondered about this before, but specifically a ratio between the mix/max speeds of a gybe. But your post got me interested so I fired up RealSpeed and looked at a handful of few sessions.

My best ever minimum speed was 12.6kt, mostly I cluster around 10. I found I got 12.5kt minAlpha two sessions ago, but I came in over a knot slower.

So I guess that tells me is that:
(a) it was a better executed gybe than my PB; and
(b) who ever mins at 16.3kts is an absolute boss!

I just once made such a jibe where the lowest speed was 32.4 km/h (17.51 knots). It was very flat water and I just concentrated on a fast exit. Usually they are around 20 km/h (10.81 knots). Or then not planing at all :). I added that calculation also to the Garmin Forerunner 920XT Windsurfing App (which is not released yet). It shows the lowest jibe speed together with the fastest 10s after each run/leg.

There may be others buried in my files, but this is the highest min speed I've saved to my alphas folder.



www.gpsteamchallenge.com.au/sailor_session/show?date=2011-03-19&team=2

The speed column on the left shows that the 15kt min only lasted 2s. Most of my alphas are more like 12kts min, everything must have gone right on this one.
It was my Avalon Sails 6.0 twin cam, that helped a lot with my alphas back then, there's no delay in the rotation, on the flip it falls into your hands fully rotated, since I've had to pump the sails to rotate them, my alpha numbers have dropped.

Amazing result Decrepit, because below 20 knots you have only 4 consecutive seconds
on the NC graph above , there are 7 s below 20ktn

Interesting is also to see when / where exactly during the gybe our slowest speed occur.
During this 180 degree U turn.
On this example 24.8 alpha 11,9 show exactly when there is full power in sail and acceleration.
If we compare this to clock it looks for me ( the critical moment like 7:00 or 7:30

The question could be: Because your bottom speed was higher, did you get power in sail earlier in the gybe ( like 6:00 or 6:30) ?

And to answer your earlier question, it would have been my version of a strap to strap laydown, Having the sail rotate as you flip it, means it's fully powered up as you grap it on the new tack, the danger is getting pulled over the front if you aren't prepared for the acceleration. But as you see, if you manage everything right, you may go slow, but you don't go slow for long.

Macro, I find it difficult to maintain speed through the gybe. On my best alpha (24kts) my slowest speed was 9kts, but my entry and exist speeds were 29kts and 30kts respectively.

Eager to learn strap to strap at,nearest occassion. I wonder if there are some limitation that make,this easier or,close,to impossible. If my standard setup like,is97 and od 7.0 will be good for training or need smaller gear?

I was analysing some of mine from last session. I did some nice ones but too wide for alphas.I think the best I went in at 21kts and exited at 13kts?

I've found its all about exit speed! The quicker you get back into the harness and foot straps. The more chance you have, at equaling your in speed and accelerating back up too full noise.

I had one of my best alpha sessions the other week. 31st October at Stanley.. Tracks can be found on KA72 and feel free to download the track.

I had 10-15 jibes. Over 27knots, all were basically around 32knots in. (Square to the wind) min of 15kts. And back up to 31 knots quite quick after the jibe.

I found this instruction for the most perfect fastest gybe.

Do you all agree with technique description here or you found any improvements?

http://www.codemaker.co.uk/ww/jibe3.htmI specifically enjoy reading this critical part ( timing our sail flip , because remind me exactly mine lack of power after every gybe exit )

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izaak said..
31st October at Stanley.. Tracks can be found on KA72 and feel free to download the track.

You are mates unbelievable, on that day so many cranking crazy fast gybes and Stanley and breaking neck speeds >40

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Macroscien said..
Amazing result Decrepit, because below 20 knots you have only 4 consecutive seconds
on the NC graph above , there are 7 s below 20ktn

Interesting is also to see when / where exactly during the gybe our slowest speed occur.
During this 180 degree U turn.
On this example 24.8 alpha 11,9 show exactly when there is full power in sail and acceleration.
If we compare this to clock it looks for me ( the critical moment like 7:00 or 7:30

The question could be: Because your bottom speed was higher, did you get power in sail earlier in the gybe ( like 6:00 or 6:30) ?

Here's a gpsvisualizer.com view of the gybes in my alphas above.




I think this shows the power is coming on just before the gybe exit. Not half way through.

And Izaak I wish I could do 30kts across the wind!

I'd forgotten about this video, I'm doing a strap to strap jibe. Was a mid 26 alpha from what I can remember. It gives you the speeds through the jibe and angles to the wind. May prove helpful. Naish Stealth 5.8 on the Naish SP80 with a Curtis/Roo 29 elliptical fin. Wind 25 to 30 knots in behind the Hood River sandbar in the Gorge.

dotsub.com/media/cf554882-9ce5-4a42-bdef-406dc09b813f/embed/eng

Select to expand quote

Macroscien said...

izaak said..
31st October at Stanley.. Tracks can be found on KA72 and feel free to download the track.

You are mates unbelievable, on that day so many cranking crazy fast gybes and Stanley and breaking neck speeds >40

My tracks is the second last on on that list.. Just under dads name on ka72. As he was logged in on there

I am just happy that I no longer come to a dead stop in the middle of my gybes...
3-4 knots min speed is progress!