Aaaaahaaaa, now I get it…I agree, I think. Its too bad I can’t draw pictures here, it would be so much easier. When you add in the angle of attack it starts to complicate things. I was initially just trying to simplify things to only two concepts and, as usual, with a surfboard there are too many things going on at one time including fins, rocker, thickness and rail shape that affect the feel. I still think the spoon/spatula thing works though…
“Water doesn’t release on a hard rail, in reality. It still tries to conform, but laminar flow is much more disrupted on hard rail than on a soft rail. So, the more hard the rail is, the more drag you get.” A contradictory case in point- the famous Hawaiian “Hot Curl” design of the late 1930s was finless... and the only way those boards could track (fast) across the wave wiith any control was with rounded rails, rounded and veed bottoms. In fact, the faster they went (and the bigger the wave), the better their performance. Common surfboards of that time were wide-tailed, square-railed, flattish slabs which had lift and release, but without any fin for stability (yet to come), everyone knew the result: “sliding ass”. Necessity was once again the mother of invention when John Kelly successfully modified his board with the introduction of bottom curvature and a dihedral tail… especially ironic, that centuries before, ancient Hawaiians had already developed sophisticated, finless, parabolic bottom and rail contours. “Not long after Fran had his semi-hollow Pacific Homes board in Hawaiian waters, it was cutdown by Kelly to make the first Hot Curl shape. The year was 1937. “We’re out in this big surf at Brown’s,” Fran told me, “and we couldn’t hold” onto the face of the waves. “That’s when the cutting was done.” “Fran’s was the first cut down,” Wally told me. “Kelly cut his down,” meaning that Kelly first cut Fran’s semi-hollow. Wally mentioned he had a copy of the original letter Dougie Forbes had written Pacific Systems Homes, ordering the board for all of $28.” “These modifications were made in Kelly’s workshop,” Fran noted. “Which was first I can’t say. But they all hit the water at the same time.” The modifications to the redwood plank essentially amounted to a V tail that held the boards onto the face of the wave similar to the function skegs perform, today. Both eliminate a board’s tendancy to – in the vernacular of the day – “slide tail” or “slide ass.” “It brought the weight down, also,” Fran pointed out. “The redwoods we had averaged about 80 pounds; after the cut, they were closer to 72.” The average redwood board length was between 10-foot 6-inches long, 20-inches wide and upwards of 90 pounds in weight. "… As to the name for their modifications, John Kelly recalls: “Wally Froiseth shouted out ‘Hey it gets you into the hot curl,’ and the name stuck.” (http://www.legendarysurfers.com/surf/legends/fran.shtml) http://www.legendarysurfers.com/surf/legends/ls14.shtml
A great website… absolutely fascinating text and photos. Note the direct parallels to flat (or concave) bottoms, sharp strakes (breakaway stepped edges) and rounded chine rails. With much inspiration from David Platt… http://www.surfresearch.com.au/00000190.html
To R Maugham to whom are you asking the question you posted?
Thanks Dale,I would also like to cogratulate Geoff Cater (Surfresearch) for the time and effort he has put into the Surfresearch web site.It is a work of art.I can’t imagin how long it would take to produce a site like Surfresearch. The modern hard edged longboards that I have owned or ridden don’t seem to noseride as well as the traditional old style boards do.When you get to the nose they are nowhere near as stable and controlable as an old style board is.I don’t know if it is me or the boards they allways felt as if they were going to spin out or nose dive.Try and picture what you are doing, and where you are standing when you are on the nose.Normally you would be positioning your weight to wave side of the stringer.Now, what is this is happening at the other end of the board? In my mind it is trying to turn more parralell to the wave and ultimatly spinning out or “releasing”. With soft rails the water is flowing over the top of the board, counter balancing the weight on the front of the board making the thrill of nose riding last longer.
NEW: Re: Hard vs Soft Rails (Yes… But…) David platt – Sunday, 21 September 2003, at 2:15 a.m. To R Maugham to whom are you asking the question you posted? My question was in reference to the opinions of “blakestah”.
Dude!
All l know is what l felt, about 20 odd years ago a couple of people said to me “mate you have to have edges on the tail for drive” so l taped up the tail and resined it on my favourite soft railed (short)board so that it had a straight down sharp square edge, l went surfing that arvo at the same bank that l surfed in the morning (5 feet), for a board that you could put in a tight situation and hold in beautifully became a board that would spin out at the thought of going vert. l took it back to work and tucked the edge under just a bit and rode it again, it held a bit better but was still abit to skatey, so l tucked it a bit more, l fine tuned it until it felt right for me, for what l wanted it to do. This is what shaping your own boards is all about and why l started to shape myself boards. l have found over the years though, that the combination of outline and bottom rocker can have the same reaction (hold or release)as soft or hard rails. So what you think might be one thing could be another. KR
Trial and error, & practical experience… learning to work with the equipment you have. These generally mean alot more than what we can read (or write), whatever the source, or forum. All this was infomative and the variables have lead to some deeper water. I’m going somewhere quiet to sit and breath - before my brain explodes. Then I’ll rethink the rails I want to put on my next blank. Thanks, Eric J