Tuesday, January 6, 2009

Polls, Fins, Gebi, Clam Sandwich

FYI, I just posted two new polls in the sidebar. I'm testing the theory that most windsurfers are engineers named John, Dave, Scott, Chris, or Mike. If your name is a close variant, like "Jon", "David" or "Michael", that's good enough; don't get persnickety and mark "other".

WARNING- Before you read any further in this post, be aware that it is mostly boring, technical windsurfing stuff. So if you are NOT an engineer named John, Dave, Scott, Chris, or Mike, you might want to think twice.

Begin post-

Guess what? I got to windsurf around sunset today with Mike Gebhardt, the OLYMPIC CHAMPION. Actually, he was kiting, and kicking my ass in terms of jumps and speed. He did that thing where you ride up alongside, just downwind, and reach out to lean on the nose of the other guy's board. Pretty cool.

It didn't bug me that he could jump higher, because everyone knows kiters can jump higher, but I wanted to be faster. Some of the speed discrepancy may have been due to the fact that I'm not an Olympic Champion who spent the last six months in Namibia working to break the kiteboarding speed record. Nevertheless, I think I could eke out a few more knots if I tuned my gear differently. I.e. if I matched my sail and fin better. The weed-wave fin I was using today (left) has a large surface area and low aspect ratio, which give it good grip and maneuverability but make it a bit sluggish. The sluggishness is pronounced when the fin is used with smaller sails, like the 5.8 I was on today. I should have used the narrow, efficient fin on the right.


The reason I didn't was that the weed-wave fin was already in the board and I was in a hurry. Before grabbing that board I had been sailing my newly-salvaged "Clam Sandwich", but I wanted to do a cross-comparison with my main ride, which is actually called the "cross". Check out the differences in the tails and fins of the cross (top) and the clam (bottom).


The clam sandwich is a lot thinner, huh? That really helps it slice a turn. Also, the fins are the same length (25 cm), but because of the area difference, the one on top is good with a sail around 7 msq and the one on bottom with a sail around 5 msq, I think.

I'm pretty stoked about the clam, especially since I got it for free and did the refurbishing myself this weekend. It was in decent shape to begin with, except for a botched rhinoplasty and bad back footstraps. The first thing I did was to move the good, front footstraps to the back, and replace them with some ok extra straps that I had lying around. Then I sawed off the pointy part of the nose and filed it into sort-of a blunt, trapezoid shape. I fiberglassed two layers over the area, then filed and sanded the worst lumps out of my glass job. I made a jaggedy, sunburst-shaped stencil and spray painted gold over the exposed fiberglass for beautification and UV protection. To integrate the sunburst aesthetic with the rest of the board I added some gold stars with more stencils. The result is "unique", IMHO. Perhaps I should call the new board the "Glam Sandwich".


PS- I was going to sell the Clam Sandwich for $90, but now as the "Glam Sandwich", the price has gone up to $100. (The epoxy and stuff I got from @#$%! West Marine cost $100.)


PeconicPuffin said...

1. You thought you'd pass a world class athlete on the water if you used a weed fin? I think the answer falls under a priori category...you don't need to discuss aspect ratios.

2. Is that a Lightning Fin I see on one of your boards? The "recreational composites"? Ten years ago I got to take one for a spin...it was the fastest fin (as far as my limited capabilities to discern could detect) I've ever sailed. If you sell the board hold on to the fin.

3. This post isn't remotely as "boring, technical" as you can get. Bring it on!

uglyjiber said...

Dude, considering what Gebi and Rob Douglass were doing in Namibia, i think there is no shame in being passed. None at all.

John I said...

Further proof of my warning about weed fins. They suck unless the weeds suck worse. Also, that stock fin for the Cross 106 works great. I guess it depends on the luck of the draw. Worx great with a 7.5 sail.

James Douglass said...

Puffin- 1) Well, I can dream. 2) Yes, it's a lightning fin and it's very sporty feeling. 3) You asked for it.

uglyjiber- There's no shame in being passed by a world-class athlete, but there is motivation, I reckon.

John- Yeah, you were right. :) Although I'm suprised you can use the 32 cm stock fin with a 7.5. I felt like I had to be well powered on 6.6 or less for my stock fin to work right. Maybe your board needs less fin because it's the lightweight pro model? Let's do some tuning at the next round of BRR board testing.

John I said...

It's All about boat speeds that are appropriate for any given kit b4 you start using heavier pressure with your back foot. Cheers.