Our Promise To You

My Environmental Promise: I use Forest Stewardship Council certified woods or woods salvaged from downed trees. All boards are glassed with epoxy resin which is cleaner for our environment and emits 50-75% less Volatile Organic Compounds than polyester resin. In my shop I have moderate ventilation and no need for a mask when glassing. Epoxy is lighter and stronger than polyester. My wood boards are nearly indestructible and should last a lifetime. Each board is quality crafted for strength, durability and concern for our environment.

My Satisfaction Promise: Ride your board for 30 days. If you don't like it, return it.

CONTACT: Dan Johnston BlindDogSurfboards@yahoo.com

All images are copyright protected and my not be used without permission from Blind Dog Surfboards.

Mar 13, 2012

Good lesson in surfboard design

Ever wonder why your friends board is a pig when you try it, yet in his/her hand it is like magic? I kind of always though it was just learning how to handle a board but it is much more than that. We've been mulling over building a short long board and have it fairly nailed down at this point. With wood, we do not have much room for error in designing ribs and spar, for foil layout and rocker numbers. What we are planning is exactly what Greg Loehr is writing about below. We picked this up off Swaylocks and it really helps all of us understand board design in a way that makes sense. Thanks Greg for letting us reprint your work.

Pitch: Every board goes through the water at a certain angle. This angle may be with the nose of the board riding high or the nose riding low. In boat and airplane design this angle is called pitch. Pitch angle is perhaps the single most important aspect when considering a surfboards riding characteristics. This is one reason shapers spend so much time and effort on the design curves related to rocker. 

Understanding Pitch: The difference in pitch angle can be effected by numerous variables. These include board design, fin design and placement, surfer ability and style, foot placement and weight distribution, and local surf conditions. With all these variables you might question just what affect a modern surfboard shaper has on the overall ride performance of a given design. Actually quite a bit but knowing who is going to be the end user and what conditions the board will be ridden in are important variables that of course cannot always be known. This can lead us into a quandary as to how to optimize performance by adjusting pitch angle in an existing board. 

Wave conditions: Wave conditions drastically effect the pitch balance of a board. A steep wave will force the board to ride very 'nose low' while a mushy wave will make the board ride 'nose high.'
 Interestingly when pilots came back from World War 2 many of them took up surfing because it has many of the same feelings as flying. When an airplane is in a nose high position it is said to be mushing. These pilots would go surfing in slow waves and their boards would mush in the in these conditions. Soon slow waves became known as mushy surf.

 Board design: Most board design characteristics effect pitch balance. Outline, thickness flow, rail shape and of course rocker. A board with a wide tail and a narrow nose will of course have a significant amount of tail lift thus making a board that tends to ride nose low. Conversely, a wider nose with a narrower tail will tend to ride nose high. A thicker tail, because of flotation of the foam will tend to ride with the tail higher. This generally forces the balance to a 'nose low' attitude. 

More rocker in a board makes for a nose high balance while a flatter rocker make for a nose low attitude. Hard rails create lift. A harder rail in the tail will lift the tail while a softer edge will ride lower in the water. So a harder rail will release water faster but will not allow you to sink as much edge in turns. Now if you combine different aspects of board design together you get different combinations that hopefully balance the pitch angle for you and your favorite surf spot.

 Weight distribution and foot placement: How you surf, where you stand on your board and how good you are at creating speed all have to do with what works for you. Do you dent your board more under your front foot, back foot or about the same under each. If you dent under your front foot, then congratulations, your a front foot surfer in the mold of the former world champ Shaun Tomson. Front foot surfers tend to need a bit looser board because the board doesn't turn as easily from the middle as from the tail and the pitch angle tends to ride a bit 'nose low.' This isn't that much of a disadvantage though because you will connect sections easier and Shaun was a great tube rider.

 If you dent under your back foot, then congratulations you are a back foot surfer in the mold of the great two time world champ Tom Carroll. This means that your board can be built a bit stiffer and should have a bit more speed built in because you will have a tendency to have the balance of the board 'nose high'. Your surfing style will keep the board loose but it does make it harder to maintain speed. But don't be disheartened. Tom Carroll is one of the fastest surfers alive and the increased rail to rail looseness of your surfing style allows you to make quick adjustments which can put you into faster places on the wave face. 

As you can see there is no right or wrong when it comes to weight distribution. There have been great front foot surfers and great back foot surfers and everything in between. So if you dent under both feet you have that in common with Kelly Slater. Need I say more. Ability: This is something you have to earn. Its nice to think that a change in equipment will make you the next Kelly Slater but we all know that doesn't seem to work. The best surfers are usually able to create speed better and that is usually through their bottom turn. 

It's that simple. Well, almost. A board that is balanced nose high is looser rail to rail, the edges don't catch as easily and is much looser in the pocket. These are real advantages BUT, you have to make the thing go. The average surfer cannot make a board accelerate the way Kelly can so he can't ride a board that surfs as nose high. Therefore he can't take advantage of these ride attributes UNLESS he improves his game. Doesn't seem fair now does it? 

Fins: Just for simplicity here, lets NOT consider the front fins on your board at all. They have an effect on another balance within your board that is beyond the scope of this article. For this article consider only the back fin on your board which is the primary CHANGEABLE aspect of pitch balance in an existing board. Simply put, the back fin, in effect, pulls the tail down and anchors it to the wave face. The bigger the fin, the more it holds and of course the higher the nose will ride. Also the further it is towards the tail, the more leverage it has to pull the tail down. A smaller fin will hold less but pull down less as well, balancing the board nose lower. By using different fins you can easily change the pitch balance of your board to optimize it for not only your own particular surfing style but for varying surf conditions as well.

 Longboards and Pitch: Longboards while quite different from shortboards in the style with which their ridden are nonetheless are affected by pitch as much as any other aquatic vehicle. Back in the longboard days of the 60's some folks would actually attach bricks to the tails of their boards to achieve more nose time. A crude and barbaric way to effect pitch balance, but still, effective in a very Neanderthal way. A larger fin would have achieved the same result but compare the cost of a new fin with the cost of a brick and I think the mind set of these early surfboard design mavens is clear.

 How to tell if your out of Balance: Does your board bog? Does it feel stiff on cutbacks? Kind of hanging half way through? Not making sections that you should be? Feel like seaweed is hanging from the fins? Check out a smaller back fin. It may free the board up and allow you to make more sections and be freer on roundhouse maneuvers. Edges seem to be catching? Rail to rail transition slow? Spinning out on cutbacks and off the tops? Sliding on bottom turns? Sliding down into the lip on tube rides? Your back fin is too small. Get something a bit larger. Not having any of these problems? Don't touch a thing! You have achieved true aquatic balance. Blessed surf design nirvana. The sacred place where all good and decent surfers find deliverance from the dreaded evils of pitch imbalance. Say Hallaluah.

1 comment:

Note: Only a member of this blog may post a comment.