Correct. Garrett made the typical newbie mistake when riding a displacement tailed board for the first time.
He did the opposite of what i suggested and made matters worse.
and by the way, no asked you to comment on my video.
So Roy.... I think you are wrong on the fins being a problem. my fins are smooth. Also, this noise which happens only at higher speeds happens on all of my boards and happens on everyone's boards that have camera's attached to it. so either its the wind rushing by the camera, or its an effect of all fins damaged or not, or its a pitch created by surfboard moving over water.
I think you're explanation of the fins making the noise due to damage is the least likely....
Roy, why do you refer to yourself in the third person sometimes?
I'm getting a little worried about you buddy.
Fin lift and fin thrust are the same thing.Quote:
And at some point you have to begin to consider not only lift, but thrust.
Yes it is a big subject.Quote:
Roy... why not introduce the concept of your tunnel fin at this point? Talk about how they work not only in terms of lift, but their effect on drag, turbulence, angle of attack, interaction with the bottom, flex, thrust... plenty to talk about there.
Half pipe tunnel fins can create lift through 180 degrees in response to changes in angle of attack, they have very low induced drag, and offer almost zero resistance to rail to rail roll, and they provide planing lift at the tail.
On my boards, I am, at least at present.Quote:
Who is the better surfer of you two?
Yes, when it comes to the riding position on the Ghost 13.Quote:
Do you think you are qualified to give Garrett McNamara surfing advice Roy?
No I don't, many people have ridden the board, have listened to my advice and/or figured out how to do it on their own and have posted excellent ride reports as a result.Quote:
You keep saying that everyone but you the rides your boards is doing it wrong.
They are very good indeed.Quote:
Maybe your boards just arent that good.
If they weren't I'd change them.
I've made boards in the past which were not ideal, these have not been promoted or made again.
Roy, one other thing about that high pitch noise once a certain speed is achieved... maybe you've never heard it probably because your boards are not able to achieve the proper speed... I've yet to see you out run a fast breaking wave, all the waves appear to be on the slower side....
It can happen to any board as it is not the board it is the fin(s). I've experienced it myself and it is easy to fix.Quote:
On another note, I have seen/heard boards that sing when the placement of one of the fins was off. These were usually ghost shaped and/or cheap boards though.
The problem can be due to very tiny errors.
Here are some links to information on the issue:
Ignored from a couple days ago.
Thanks for putting this up.
I'll say it again, I and a large portion of the SI crowd have a different idea of what performing on a surfboard means. Like I said earlier, you have a go-fast, go-straight board and in your mind that is the epitome of efficiency. That's fine with me.
I think the surfer's idea of performance in this video have more in common with a lot of the SI users. In the video at 1:36 Beano tries a couple times to make a front side turn up the face of the wave. He tries this unsuccessfully then moves back further on the board to try again and still can't do it and finishes out the ride by jumping over the wave at 1:45.
Later, when Jay is on the board he seems to be riding further back on the board as well and getting bumped around pretty violently but still holding on at 3:18 you can see he is trying to trim up to find the high line and at 3:24 attempts a backside turn down the wave and the board proves to be too unstable for him to complete the turn. The later rides show him trying to carve but unable to as the back of the board is too deep in the water.
I know that these guy obviously don't know how to ride this board as you stated earlier. You ride closer to the nose than them. However, this video and their surfing also serve as examples of how the board they're riding, that shares similar design principles to your other boards, is able to catch waves and trim but fails when a carving turn is attempted.
Early on in the Naval Architecture of Planing Hull by Lindsay Lord he writes of the early Japanese and Italian PT boats with 1800 HP that "took ten boat lengths to turn, with speed falling off badly during the turn." We see evidence of this with your videos. These surfers attempted turns and were punished for it, you trim but attempt no turns. We've seen this many times through the videos you've provided.
Again, as I've said earlier, there is a problem with the definition of performance. In my opinion, your definition of performance is riding a wave for as long as possible with minimal movement. My definition of performance would also be riding a wave as long as possible but meanwhile, I try to see the top and bottom of the wave and with a powerful turn in there if possible.... throwing buckets if you will. That's just me and my level of progression right now. If you are at the top of the game for the boards you're making and riding how do you see them progressing? I see people riding modern surfboard doing backflips now. Where is the future performance of your designs going?
My boards are very fast as can be seen in the makaha video posted here where I outrun fast breaking sections...many people have commented on the speed shown in that video and of the speed of my boards in general. they've been recorded at speeds over 30mph many times and our best recorded speed is 37mph,achieved in low period swell head high beach break waves.
The sound can occur at moderate speeds in the 15 to 20 mph range, it also depends upon the angle of attack.
The sound reduces the efficiency of the board and should be eliminated. The inefficiency will also exist when the sound is inaudible in magnitude.