TBG5 Step Up

[SJB]

Nomas...at one time I made the assumption that having all four appendages in play had to result in maximum speed. I used to apply this technique on my standard Austin. When I got the T2 (less volume) I began to question this assumption and took both boards for a time test in a 50 meter swimming pool. Much to my surprise I had more speed when just using my legs. I attribute this to the probability that when I was applying all four appendages to the task drag was increased and none of the four appendages were working at 100% capacity. Now it is legs only with one arm assist at the point of take off. Found the same to be true with the T4.
Please give me a heads up when you see a likely possibility at Pitas. Would like to join.

[nomastomas]

Yes, one or the other is probably the way to go, but maybe the extra length will help. How long is your Austin? The whole tide/wind/swell thing hasn't come together for Pitas yet. It's been either too windy, too much tide or too little swell. I spent a week there , 2 weeks ago, and even the beach breaks between Pitas and Hobson were inaccessible until after 1p, and by then it was blown-out. I'm always checking so I'll let you know if a window of opportunity presents itself.

[SJB]

Standard Austin is 50 inches by 20.5 inches by 2.5 inches.

[SJB]

I am pessimistic about more length better promoting all four appendage action. On the 50 inch Austin it was a trade off between getting far enough forward to avoid a "plowing" plane with a corresponding issue as to where the board hit my legs. I.E. the further forward I was the more restricted was my kick because my legs were not fully submerged in the water. I am 5'9". I suspect that more length would merely exacerbate this betwixt and between conundrum.
For me....better to use my arms to keep the board on plane while fully submerging my legs and maximizing the kick.

[nomastomas]

I tend to agree. It should be noted that shortboarders frequently kick when taking off. But I understand that this is more of a way to get the legs up on plane, than for propulsion.

[jbw4600]

That's a nice design. It will be interesting to see how it rides. I have been toying with making two longer designs. One to help paddling around and catching bigger waves up here at Ocean beach and other places. However, I was surprised to see how well my 48" board with a slight fish kicks/paddles. It feels like it kicks and paddles better than my longer boards. I think one of the reasons it kick and paddles better is that the fish tail allows me lie further up on the board when I kicking. Anyway it be interesting to see how your new design does. I am still thinking about making about 54 1/2 with a rounded nose.

[bgreen]

In my quest for a board that paddles but is low enough volume to easily duckdive, I was thinking that a board that "paddles" well needn't be a board that catches a wave well. Any thoughts on this Nomas? There seem to be lots of variables to consider.
Bob

[nomastomas]

In my quest for a board that paddles but is low enough volume to easily duckdive, I was thinking that a board that "paddles" well needn't be a board that catches a wave well. Any thoughts on this Nomas? There seem to be lots of variables to consider.
Bob

True, indeed...its like rocker, the end numbers don't tell the whole story. Flat water paddling is made easier by anything that helps to get board and rider up on plane. That "anything" could be volume, surface area, material buoyancy, etc. Catching waves usually requires paddling, but there's a host of other dynamic variables that come into play, e.g. wave size, wave speed, paddling efficiency of craft, wave judgement, etc. In some cases, no paddling is even required to catch the wave. Perhaps more to Bob's point, the location of the volume within the design (the "foil") can impact wave-catching immensely. Too far forward, and the tail will drag while riding, while too far back and the board will resist penetrating the lip at take-off, and will tip forward at the last minute leading to a nose-dive. The rider can alter his position on the board to compensate for one or the other, but this movement is far easier on a stand-up board than a prone board that is typically shorter than the rider's height.

With the TBX, I extended length to (1) increase planing surface and (2) to increase volume, both in service of producing greater max speed by improving planing efficiency. However, I also moved the bulk of the volume forward to allow for easier lip penetration at take-off, while keeping it where I plan to be riding after take-off. Some of you may recall that the G2-G4 models were designed to minimize the necessity of rider movement after take-off. As a result, these p-boards require a later take-off, than the typical body board which has very little deviation in its foil.

[Nels]

I played around with a couple of boards to get a feel for length issues. 66" Doyle tri-fin was one, and I think the other was a 68" kneeboard. Both were bears to paddle for me and horrible to use with swim fins. Both were fine to ride though (although not technically "good" for bellyboarding really, both having been designed for other realms). I've never been a fan of really short boards even when I was surfing them, but then I probably drag a lifetime of surf-baggage with me (California point wave devotee, enjoyer of reef breaks, hate leashes, forced by crowds into more and more beach breaks, etc.). The hassle of getting outside on those boards far outweighed benefits of the longer length for me. Would rather go the longboard paipo route.

Quite possibly I would feel different if I were 20 rather than a long way further on down the road...fair enough.

That 54" mark seems to work as a good mid-range for me (at 5'8"), decent to kick with fins but allows efficient enough arm paddling. Wish somebody made a 60" paipo blank...

Nels

[nomastomas]

"I think one of the reasons it kick and paddles better is that the fish tail allows me lie further up on the board when I kicking" -jbw

True, but then you loose the leg support that the extra length provides. The fork nose accomplishes the same thing, theoretically at least, i.e. allowing the rider to reach the nose with legs in good kicking position. But it then allows the rider to slide up and gain leg support from the tailblock while riding.

[krusher74]

Nomas...at one time I made the assumption that having all four appendages in play had to result in maximum speed. I used to apply this technique on my standard Austin. When I got the T2 (less volume) I began to question this assumption and took both boards for a time test in a 50 meter swimming pool. Much to my surprise I had more speed when just using my legs. I attribute this to the probability that when I was applying all four appendages to the task drag was increased and none of the four appendages were working at 100% capacity. Now it is legs only with one arm assist at the point of take off. Found the same to be true with the T4.
Please give me a heads up when you see a likely possibility at Pitas. Would like to join.

If I leg paddle then my groin is in the V of the back of the board, this allows an efficient full leg kick, hand on the front of the board pushing it down flat on the water, and other arm can be used for extra clawing into take off (this is all standard to bodyboarding)

If arm paddling, i almost have my knee caps on the back corners of the board, this get the board flat in the water for least drag, and stops the tail down nose up snowplow that occurs if trying to arm paddle with weight back of central balance point.

IMO trying to use all 4 limps is counter productive to glide.

[bgreen]

Another dimension.

My latest board is about a 1" shorter than my usual board length 53-54". It's also lower volume. However, when it comes to wave catching it is quite different in that I don't find myself kicking air at the point of trying to get into the wave face.. Both are S deck style foil. The overall shapes are quite similar, though the nose of the new board is a little more pointed. The bottoms are quite different though. The new board is way lighter. I'm not quite sure why these boards are so different when it comes to catching waves. The longest paipo board I've ridden is 57" but relatively low volume.

Bob

[nomastomas]

Another dimension.

My latest board is about a 1" shorter than my usual board length 53-54". It's also lower volume. However, when it comes to wave catching it is quite different in that I don't find myself kicking air at the point of trying to get into the wave face.. Both are S deck style foil. The overall shapes are quite similar, though the nose of the new board is a little more pointed. The bottoms are quite different though. The new board is way lighter. I'm not quite sure why these boards are so different when it comes to catching waves. The longest paipo board I've ridden is 57" but relatively low volume.

Bob

Penetrating the lip at the point of take-off is critical to a smooth take-off. Board and rider remain relatively horizontal, but sunk 6"-12" into the top of the pitching wave. Too much volume and/or max volume in the wrong place, and the board stays on the top of the wave, while the wave rolls under leaving board and rider behind. Or, the board lurches forward and down the face too late, resulting in air-drop into the pocket(best case) or getting pitched over the falls (worse case). Wave steepness also enter into formula, as well as wave size. Longer boards afford a bigger sweet spot for max volume placement, but present other impediments to performance. Flatter boards also take-off easier, but there is a performance trade-off to flat rocker. The list go on and on. When building/designing a shape, there is a multiplicity of variables that must be considered and integrated into the final design. There is danger in considering one aspect of the design in isolation. 'The whole is greater than the sum of the parts' With the TBX, I increased the length to gain more planning area, then I shift both max volume and max width forward to lessen the resistance to sinking into the lip at take-off, and to locate max volume where it will support the rider in the new, more forward riding position. Longer length requires more rocker, so that was adjusted as well, both along the centerline and out at the rail (the V tail was helpful here).

[bgreen]

Full wave that suddenly jacked - to steep, is one set of conditions that come to mind.

[Poobah]

Early in the thread you mentioned a forked nose. Have you considered something more subtle, like the crescent nose on the Turbo Z?

http://www.vintagebodyboards.com/item.asp?ID=059

[nomastomas]

A crescent wouldn't give me the recessed depth I need, and therefore, wouldn't be functional. Function always trumps form in my opinion. I'm not concerned about how it will look, but rather how it will work. Blank should arrive this week.

[krusher74]

It will be interesting to see how the Nose will feel/work ergonomically.

The parallel I can think of when I tried Bgreen's blue board with the handle (I would say the handle is in a similar place to where your cut out is and is similar width)

I noticed that bringing the hand/s closer together reduces TQ angles of leverage, I found I had to just lean my weight on the board more than being able to draw lines directed by m leading hand.

It worked, but felt like a bicycle that very narrow handle bars.

Maybe on the larger waves this board is designed for it will help in smoothing out slow carving turns

[nomastomas]

The flat nose of the G4 is narrow, intentionally only as wide as my two hands, so I'm already comfortable in that position. To snap a turn, I weigh the rear rail (on the inside of the turn) with my hip and pull up on the nose to release the forward rail, driving off of the fins. Carving turns don't require as much nose lift, just power off the fins. Not a lot of effort to basically roll from one side to the other. EZ-PZ. Coming from a fin-less boogie-board background, the biggest adjustment I had to make when riding the G2-G4 was to trust the design and use the fins instead of the rail for holding position on the face and for turning.

Blank was delivered yesterday, and I'm totally stoked with the results. I'll shoot some pix today if I have time.

[nomastomas]

Got it pretty much scrubbed and the fork nose rough-shaped. Sitill needs some finishing, but here's a peek...note V in tail, slight concaves in outboard panels and flat middle panel. Deck concave is deeper than the G4, rocker flatter in tail to avoid speed max-out, and thickness has been shifted forward. Comes in at about 25.5L. Happy Thanksgiving to all!

[krusher74]

Cool stuff,loads of optical illusions going on in those pics!