Just a question regarding that above mentionned matter.
Without copying a known shape how can I know before trying the board that I should have that much tucked under edge.
I have already checked the archives about the tucked under edge matter but I still need some infos.
Example : the surfing spot has punchy waves so how much tucked under should I put in the shape, other case the waves are kind of mellow, how much in that case.
I know I know the question may sound stup… but just wondering how a pro shaper is able to decide how much.
I am aware that a board is more than a tucked under edge, you have the rocker, the thickness, foil…and all that together makes the board
For instance you come to the point you are about to shape the rails so when you have to decide about the tucked under edge how do u decide and what makes you decide this or that way.
Thanks for considering my question, any comments more than welcome.
Observation as to what other riders are using in those wave conditions.
Then apply a little knowledge…more tuck softer ride, less tuck more sharp ride…then maybe knowing what the rider you are building the board wants in feel, add your preferences for shaping but mostly sanding and filling, then walla, you got a boardshape based on everything YOU know.
Find a board you like and take a carpenter’s square to the bottom so you can measure between the rail apex and the inside corner of the square as well as from the flat bottom to the inside corner of the square. Do this every foot or so along the length of the board and you will have a set of numbers that will give you a starting point. I think the underside of the rail is a key element in how a board behaves.
Think about water releasing or “letting go” of the board. If the water is traveling along the rail, and suddenly the rail is gone, the water has nothing to hold onto, so it lets go. (think about the hard edge at the tail.)
If the form turns as the water is running against it, the water will “suck up” against the form. Put your finger under a sink faucet, and see how it sort of grips onto the roundness of your finger. now try it with a knife.
If the water sucks against the tail of your board, it will slow you down. If the water sucks against the midpoint rail. it will keep you from slashing a turn, but instead give a smoother carve.
Now to the design. If you want the board to hold a high line and not slip out, then about 1/2" to 3/4" tucked at midpoint. If you want a slippery slashing feel, then less.
Another effect, which most shapers don’t seem to do anymore, came from putting a “tucked edge” along the length of the rail
That gave a slashing sort of turn, but still held on a wall.
How much tuck is decided by taking a board you are currently riding, and adding more or less of an element to get the turn you want.
I wish there was a more objective answer, but it is all about feel. Figure out what you like, or better yet what your customer likes and do that. Two boards with same outline, foil and deck dome can ride very different with different rail profiles. I’ll agree with JohnMellor that the underside of a rail is one of the more important parts of board design, but then again Ive screwed up the underside rail edge and the board still seems to work…
Once again, it is kind of meaningless to isolate one single component. That measuring thing I posted was just to reference a single board.
A fully rounded bottom (with no edge) will hold fine on steep waves and hard turns if there is enough finnage, the rails are thin enough, and the tail narrow enough.
…"tuck adds control , in punchy waves , but slows you down in soft waves "
I am kind of lost with that comment. I got the point where the edge of the tucked under helps the release of water and avoid the suck up effect.
I don’t understand Mr BURGER’s comment, a tuck slows you down in soft waves.
I thought that in mellow waves the suck up effect would be higher than in punchy waves and that by having a tucked under edge for instance the release of water would be better so that you would not slow down.
I am a rookie so I am trying to understand.
I also thought that a tucked under helps you with the banking of the rail in the water and allow more stability when turning.
The tucked under is quite subtle for me therefor all those questions.
I love the tucked under edge. I like that they allow the board to go faster than a rounded off rail, and add a bit of drag compared to a squared edge.
My friends favorite 10’ sparky longboard has tucked under rails all the way.
The second drawing looks exactly like the rails on my Griffin 5 fin fish. It’s like that almost all the way from nose to tail.
That board works well in every kind of wave I ride, which is along the south shore of Oahu from Diamond head to Barber’s point. There’s quite a range in there from fast round reef waves to mushy beach breaks. I’ve ridden the board in waves up to 10’ faces, and with the 5 fins it holds on heavy turns, yet it still works great in waist high mush.
I do believe that the flat bottom and the rocker are as important though, and it’s tricky to glass a flat bottom board with tucked under edges. Sometimes I add just a tiny bit of a bevel going in about an inch in on the bottom to allow for the laps.
In my experience if you wrap the rails too far and don’t make a distinct edge under the board you end up with the board bobbing in the water like a ball. As you push down on the board it sinks in the water and then bobs up - sort of a spongy response. It does this until you get enough speed to provide lift. I think this is why Bert suggests they lack speed in small waves. You feel it when you do floaters or free falls, too. The boardI sort of sinks into the water upon impact, gathers its breath and then starts moving forward again.
Obviously the same effect gives you a lot more control in evil conditions. I had a board that allowed me to win a contest with full blown turns when everyone else was just trying to navigate the bumps and ledges.
Reduce the undertuck and reduce the effect. I liked a post a few years ago with a spiral suggested as an inspiration for rail profiles, so even 50/50 rails end up with a relaxed top roll and much tighter bottom roll.
PS rails in the nose work well if the spiral is “flipped” - relaxed bottom roll into tight top roll.
A tucked edge in the nose will cause the board to catch a rail dring a cut back in semi softer waves. For most of us a soft nose in the top 3rd of the board will really help…it makes a more forgiving board. As for the back 3rd or maybe 18-20 inches this is where you really need to start making a hard edge. With a lot of emphisis on the last 12 inches. I personally like to make it razor sharp. I like to put the edge right where the fins start so the whole cluster and rail edge has this huge bitting surface to grip on a wave. I’m not talking about a square boxy edge, but a tucked edge releasing to a sharp transition.
Once again, it is kind of meaningless to isolate one single component. That measuring thing I posted was just to reference a single board.
Listen to Mr. Mellor your rail contours need to work with your outline, bottom contours and rocker you can’t think of any of them as isolated components That’s what people don’t understand about Chandler’s(Greg Griffin) design. Every experienced shaper will tell you the same Also keep things simple Tuck does a couple of things First it influences release so the water doesn’t have to ride up the rail before exiting the board’s surface. when combined with a supporting outline and a certain bottom you can actually continually increase the speed of the water releasing from the outline as the water travels along it. Secondly it affects what the bottom sees as the edge of the board in relation to the rocker as the rocker defined at the apex of the outline may be different than the rocker defined at where the edge of the tuck runs along the bottom. Finally it lets you get from rail to rail faster kind of like a concave increasing manuverability. Everytime the water jets off the edge of the tuck it provides thrust as you move the board from rail to rail you can use this thrust to accelerate although its your fins that are actually providing the majority of your forward thrust of a turn. hopefully some of this makes sense I’m no expert surfboard maker this is all from riding hundreds of designs over the last 30-40 years trying to find some “miracle” surfboard design you want to see an engineer’s vision of tuck go look at what Tom Morey is doing with it There’s a big difference between a “sharp” edge and a tucked edged. A well thoughout tucked edge won’t catch up front but a sharp edge will especially with a full nose. The typical Mctavish tri-staged bottom rocker(flip nose/flat middle/flip tail) won’t support a full tucked edge all that well cause of the staged flat area that’s why you have soft nose rails and super sharp tail edges. Banana rockers don’t go all that well either unless they’re deeply concaved like loehr/webber did with them. you have to deal with the whole design.
Quote:
A fully rounded bottom (with no edge) will hold fine on steep waves and hard turns if there is enough finnage, the rails are thin enough, and the tail narrow enough.
Sounds like your describing the board roy sent here to a “T”…
Thank you so much for sharing all those detailled answers that helped me understand way more.
You see for instance I just thought that having a tucked under in the nose area would be a good thing for the release of water so it would avoid the catch a rail thing.
I guess I was wrong with that one
Last question : does all this, I mean the different details regarding the tucked under aspect apply to all kinds of boards?!!or is it specific to certain boards?
Actually, I don’t agree that you are wrong about the tucked edge in the nose area. On my boards I run a tucked edge along the entire length of the board! Depending on the type of board the edge could start out hard in the nose become more tucked in the center and then back to hard in the tail.
A lot of people coming to me for boards ask the question whether this type of rail will catch, the minute they ride the board the first thing they comment about is that the opposite is true!
My experience on boards ranging from shortboards all the way to large guns is that a tucked edge in the nose DOES NOT catch! Now that said there are a lot of other things to consider as everyone here has already mentioned. Rocker, rail profile, bottom shape, it all needs to be fit together.
But in general my experience is that a tucked edge is very beneficial, I put them on every board I shape regardless of the type of board. Except of course if it is some retro longboard with 50/50 rails! Now admittedly on longboards I typically treat the nose differently as there I’m more likely to use a beveled rail through the nose area as it is more forgiving. But I still run an edge at the transition of the bevel to the bottom. So there is still an edge running around the entire perimeter of the bottom.
I find that the tucked edge gives more “feel” to the board, as well as the stated release characteristics. Feedback from my customers indicates that they feel the same way.
Just my opinion based on experience using this type of edge for sometime now.
