Which rail at tail?

I am just in the process of shaping my second board and would like to know which shape for tail rail is best and why?



Well I know everything from EPS will float and I can even ride doors from my house , but I am at point when I want best performance from my board and even more I want to know some theory why it works like that.

Ok, here I made some pics of profile of rails at tail. Wonder which one will work best?



Wakesurfboards are pretty thick at tail compared to regular shortboards therefore sidewall of rail is prety high so I wonder how it affect board performance and how water flow and bend there?
Board will have squash tail and I will ad wings on rails to brake flow of the water like Strech said on his website "...Single wing ... These will pull in the wide tail outline at the fins as a way to break the water along the rail line and add quick response and maneuverability in tight pockets."

Love the giant pizza box shaping "room" I also like the general shape you have started there.

I was just in Texas and saw a few boards that will be "new" for the 2010 season. Some of the smaller private labels are going HUGE in terms of thickness on the tail. Seemed to work well, but I think you need to be careful to avoid a feeling of corkiness. I don't know where a good cutoff is in that regard. Thickness between the skins increases stiffness and volume. Any bottom contour work that exits the tail almost requires a fairly thick tail.

I like a domed deck if there is substantial thickness through the tail...more like C. Actually I like that general shape even if there isn't much volume in the tail.

Thanx Jeff I also prefer that shape C.

Hehe that pizza box is just my "patented zero mess bay" because I can only hand-shape on my balcony now - (definitely not good place to use my electric planner. ) Just shred a little of foam - clean with vacuum cleaner and so on. Slow but tidy.

Now I am working on concave to slight vee bottom and soon I will post rest of my work.

(Message edited by hawaj on July 08, 2009)

I must be totally confused. Somebody explain to me what the 'rail' is on the above A,B,C,D examples.

Hope this helps

http://www.nssia.org/SURF%20COACH%20BOOK/5_Surfboard_Shaping.htm#raildesign

http://www.surfaus.com.au/surfboard-info/surfboard-rail-styles-12.html

Yes, helpful, thanks. I was thinking before that the 'rail' on b,c,and d looks to be the same to me....

Actually I am usually more confused than you dtw. because english is not my native language

Here is our rail set up on a winged quad

JL nice looking shape...but...I can't make out any details in the rail shape on that board. Got any close-ups?

Petr - I had to laugh at the shape, shape, shape...whirrrrrrrrrrrrrr of the vacuum sequence.

So you're doing a single to V out the tail? Where will the transition be - before the fins? Ezra / Props...I think it is the EZ1 model does a single to V. I never have seen that board up close though. I've seen a few kiteboards that use that bottom. The single runs under the feet and then fades to a slight V out he tail.

JL this is very nice shape! I like subtle channels on top. Yea I would like to see some close ups too. Wonder if is top deck flat or with some concave?

Jeff - he he I was always scary about huge mess from shaping but I find out that with EPS foam and without hi speed powertools I can keep whole process very clean ant thats great.. Also with hotwiring you got very little amount of excess foam and more exact shape than with digging shape from factory blank.

As for bottom I am doing single concave (aprox 2 mm) to slight 'v' tail. My first board was totally flat so now is time for more intrigue things. I guess transition to 'v' will be after the fins. What you think?

(Message edited by hawaj on July 09, 2009)

(Message edited by hawaj on July 09, 2009)

Yeah, the hotwiring really makes things cleaner.

So you're only going 2mm? That's less than an 1/8", so pretty subtle. I typically can't tell the difference between flat and a single 'cave less than 1/4" / 6mm. I've seen that single to vee on a few big wave boards, if memory serves and THAT is questionable. The SS Comp 1 forerunner ran a Vee out the tail, but I think it was flat or very VERY mild single through the feet.

I don't know, personally I feel we have pretty clean wave faces and I have always like the speed and lift from a single to flat out the tail. The most unique tail exit I have ever seen was from Eric Roush. He would run a channels out the tail, but the very back had what he called a power pocket. The rocker at the very back would curve (in a concave looking at it from the side) and create a hook. When you'd load the board up like for an aerial, that pocket or hook, would sort of pop the board out of the water. It also seemed to release really well, which seems counter-intuitive to me.

I've made a REAL crude drawing to illustrate. It's a gross exaggeration, but you get the idea.

I'm looking forward to seeing your final shape, Petr.

Interesting Jeff, I really dont know how deep concave shoud I do. You know I am still at point zero as I made only one board so I will listen to every your advice.
As I rember from bigger boards all bottom contours were mostly subtle so I choose less. But final decision I always make only after I shape it into the foam and look at it. Maybe than I will go deeper.

So you think that sigle to Vee is not good? I somehow thinked that its used on Stixx or other boards.
And how you compare single concave to flat vs single to double at tail for thruster?

Oh that Roush's hook is damn crazy thing!!! Looks very counter-intuitive, but you first must try it before take any judgement. Hmm maybe I will try on some other board. So as I understand it was only at the end of channel right?
How big it was?

btw just now I won some cheap airbrush compressor in auction soI will play more with colours he he.


JL: what shape of bottom you will use for your quad?

quad bottom quad rail


Sleigh Skate

some of the concept being glassed

Thanx for pics J.L. That quad looks neat I like it.

Wow that concept board looks like moon fish