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Finned Xylem Paipo

Posted: Sun Mar 29, 2015 12:42 pm
by PhillyViking
I have been riding finless piapo and surf mats for a few years now. In most conditions I can control either to go where I want to go. However, in some conditions I felt like some combination of my skill level and finless craft design was a constraint .. I am thinking of very late takeoffs in heavy overhead to double overhead conditions where there is a narrow window of opportunity to make the face. It requires optimal drive and projection off of turns. Sometimes I could not quite get there while my pals on finned boards could.

While I considered that I just need more skill riding finless I also reflected on my purpose which is fun and connection to nature .. not to be an uber anything. In any case it was time to explore board fins. I have been surprised at how well I could maunever my finless Xylem Preacher so reasoned it just needed some help. I wanted to keep the natural feel of the paipo. I worked with Josh at Xylem, got advise from Rod Rodgers and ended up with two FCS tabs on each side and three for the center. That provided lots of configuration options to explore.
image.jpeg
Xylem with FCS fins
I got several Nubster fins reasoning that since I wanted to retain the natural character of the board, small would be good.

Incidenly, the Xylem is very flat front to back but has a healthy roll side to side for the entire length. That roll in combination with parallel rails seems to be the source of magic that makes it turn so well finless. In theory the roll both creates stick for turns while also helping move water from the board. I can only say that finless, it seems to a good job at turning and speed but not as well as boards optimized for one or the other motivations.

I considered asking for nose rocker. The standard Xylem is practically flat with just some taper from the top as well as bottom. It does have the side to side roll. I decided I did not want to introduce drag from nose rocker. I am glad I did. I have managed to avoid pearling and the nose design seems to pierce and lift on its own. Its hard to sort out but there might be more spray in chop with this design .. In any case, I would not change it.

Using the nubsters and 4.5" Ronix center fin, I got to try finned riding on the North Shore of Oahu in the fall and then again in Costa Rica in March. Given the varied conditions and my varied state I still have a pile of unanswered questions. I was also riding my 4GF mat on those trips. Here is what I can say:

* using one Nubster on each side in the forward position and one in the rear center position I made some waves I would not have made finless. I did so while retaining the natural feel of the board.
* set up as a quad + center using all nubsters felt overly locked in and the natural feel was lost
* using the 4.5" center by itself seemed to work but I suspect the 2 + 1 nubster config is better

I am admittedly confused about there being any impact from drag from fins. I rode my mat on these trips when not riding finned paipo .. I did not ride finless paipo as a control so this is bad science. While the finned paipo was very fast in steep sections (benefitting from control) it seemed to maybe be slower down the line in slower sections and have more drag during long paddles.. The jury is still out.

It may be that the current board has too much toe-in. Assuming there is actually unecassary drag then resetting the plugs to straight would help. There also a question about base vs the height of the fins. Nubsters have prortionally more base than many fins designed to be sides.

So, next steps include resetting the toe in and trying different sides with less base. I also need to try to ride finless in the same conditions and time frame as the finned trials. I am happy to say that this is all more complicated in that my mat riding skill improved this year. Will be interesting to get back to finless paipo. Who knows?

Re: Finned Xylem Paipo

Posted: Sun Mar 29, 2015 1:52 pm
by krusher74
Interesting stuff. :D

how long is that board? and congratulations on not pearling it if it has no nose rocker.

When I tried a friends board with very little nose rocker, I felt as though i had to wheelie down the face on the tail to keep the nose out on a steep drop, possible, but felt more like riding a bucking bronco.

Re: Finned Xylem Paipo

Posted: Sun Mar 29, 2015 3:50 pm
by PhillyViking
The board is 48" long. It does have 3/8" "taper" in the tip of the nose starting 3" back. Maybe I should call that rocker? That transitions into the side to side roll a couple inches back as well.

The trick in not pearling is to get on to the side rails at the right moment. However there does seem to something in the design that works in less than perfect executions.

Re: Finned Xylem Paipo

Posted: Sun Mar 29, 2015 4:40 pm
by rodndtube
I am fairly certain you tried the fins pictured below in addition to the Knubsters. In both instances you detected a ton of drag when paddling whereas nil drag when using only the 4.5" center fin. Toe-in very much seems to be the cause of the drag.

Re: Finned Xylem Paipo

Posted: Sun Mar 29, 2015 9:19 pm
by Atlantasurfer
Very cool stuff.

How do you think this hybrid beast compared to finned/fiberglass paipos when it comes to speed and maneuverability? The outline and fin arrangement seem pretty close to what you might find on an Austin. In other words, what is the real effect of the flotation? I would think flotation would be a big help if you are trying to catch a wave that is already breaking a little bit (or maybe not).

If a board is set up as a single fin plus sidebites, do the sidebites need toe-in to function? Why is toe-in so common? My Mini-Simmonsish twin fin has no discernible toe-in at all.

Re: Finned Xylem Paipo

Posted: Sun Mar 29, 2015 10:27 pm
by rodndtube
My general impression is that there is a ton of toe-in on the hybrid Xylem. Combined with a convex hull that has the potential to create perceptible drag, but has I have not paddled the hybrid, with or without fins, I can't comment based upon experience. As to watching the Viking riding waves on his mats, Omni and Lotus, his speeds on the Xylem with fins was noticeably faster and that was just a basically on down-the-line riding, not with maneuvers for effect, plus on a couple of steeper faces. Not to take anything away from the "feel" on the mats, but just for keel-in-the-water speed, the finned Xylem appeared superior, and with an adjusted fin setup could be even better. The Xylem is a nice board as is... in the end it comes down to rider preference and style on whether foam/glass, wood or mats are the choice. More sea trials!!!

Re: Finned Xylem Paipo

Posted: Mon Mar 30, 2015 11:54 pm
by PhillyViking
Right, I neglected to mention the test with Vektors as sides. They have more height and less base than the nubsters but felt drag. I would have to reset the toe-in to straight to conclude on nubsters or Vektors.

Funny, Rod perceived me as having more speed on the Xylem and my perception was that I had more on the mat with some exceptions. Different rides or just different perception?

Regarding foam/glass alternative.. I started on an Austin big boy a few years back. At that time I was bigger and the East Coat waves smaller than those I now ride traveling. It now feels way to big for me. I might try a right sized foam/glass board in the next year or just stay focused on refining my skill on the mats and xylem. If I do go foam/glass it will an increment up from the xylem rather than down from the big boy float wise. Too much board makes me feel like I am riding the board rather than the wave. If I need to choose, I will take feel over performance.

Re: Finned Xylem Paipo

Posted: Tue Mar 31, 2015 1:30 am
by krusher74
PhillyViking wrote:The board is 48" long. It does have 3/8" "taper" in the tip of the nose starting 3" back. Maybe I should call that rocker? That transitions into the side to side roll a couple inches back as well.
The trick in not pearling is to get on to the side rails at the right moment. However there does seem to something in the design that works in less than perfect executions.

I would say that what you have described in that "trick" is a way of avoiding parts of the wave that has high curve and would need rocker to ride.

For example with rocker I can take off board pointed straight to the beach, go don the fae straight, gain maximum speed on the drop and then bottom turn tranfering that speed to speed along that face, with a rockerless board you would have to more angle take off.

I would think a little nose rocker in the future would allow you access toother parts of the wave and now really slow you down as most of the time you ride the back of the board, :D

Re: Finned Xylem Paipo

Posted: Tue Mar 31, 2015 1:37 am
by krusher74
Atlantasurfer wrote:Very cool stuff.

How do you think this hybrid beast compared to finned/fiberglass paipos when it comes to speed and maneuverability? The outline and fin arrangement seem pretty close to what you might find on an Austin. In other words, what is the real effect of the flotation? I would think flotation would be a big help if you are trying to catch a wave that is already breaking a little bit (or maybe not).

If a board is set up as a single fin plus sidebites, do the sidebites need toe-in to function? Why is toe-in so common? My Mini-Simmonsish twin fin has no discernible toe-in at all.

Toe in helps in initiate turning, on a twin fin or quad when turning your using the 1 or 2 fins on the rail mainly. Imagine it like the front wheels of a car, 0 Toe the car is going straight with wheels pointed straight forward with least resistance. When your turn the steering wheel you give the front wheels toe in (inside wheel toe out) and the car turns.

Imagine if a cars front wheels both pointed in all the time (like toed in fins) the tyres would be scrubbing and creating drag.

Re: Finned Xylem Paipo

Posted: Tue Mar 31, 2015 9:06 am
by PhillyViking
Correct that riding flat nose rocker constrains big bottom turns on toothy waves requiring earlier turns,, angled take offs, or riding back further. However, I only ride way back in situations where I am committed and all the nose rocker in the world would not help.. That's rare. I make a point of sliding up and going for it otherwise. But yes , the flat nose is a constraint. So the argument against flat is.. There is more to gain in speed from projection out of turns then to be gained by flat out speed.

I get the case for and against toe in. Likewise, the argument is that there is more speed to be gained by optimal turning then there is straight out glide. I suppose balance is the key.

So that comes back to style and preference. I like the feel of my mat and finless Xylem so will stick with them based on conditions and my mood. I am starting to think that for situations where I do need optimal performance I will need to have a finned foam/glass board in the quiver. My insanity is that I keep thinking that if I just get a little more skill I can do it all on a mat.

Re: Finned Xylem Paipo

Posted: Tue Mar 31, 2015 9:58 am
by Daryl D
I've really enjoyed this thread. I have a finless Xylem 52" long 1 1/2 thick at the wide point, a more conventional concave, two channel board, 48' long 20" at it's widest and 3/4 thick at it's thickest, a T Belly G2, and surf mat. Just finished two, very thin scrap wood paipos 1/2 thick at the thickest, with single channel channel in the center. One is 50" long the other 36". The short one is shaped a bit like a peanut with a pin tail. Had it out in some overhead stuff last week and it's a trip. So, where am I going with all this? Each board has it's own personality, it's own sweet spot, and it's own short comings. The fun for me is figuring those things out and exploring them. I really can't come to grips with the surf mat, mainly because of the sloppy waves we have where I spend most of my time. I prefer the finless wood, but there are times when the T-Belly just feels good. The thin board concept has been interesting because I weigh 225 lbs, works well. Bottom line, deep doing what you're doing and have fun doing it, don't be afraid to explore.

Re: Finned Xylem Paipo

Posted: Wed Apr 01, 2015 7:53 am
by krusher74
I tried a mat out last fall on a surf trip where I was offered the use of one, loved the glide opened my mind to new laces on a wave, but as you said I think I would only like one in good pealing waves

Re: Finned Xylem Paipo

Posted: Wed Apr 01, 2015 12:14 pm
by nomastomas
If you decide to use fins:

Symmetrically-foiled (foiled on both sides) rail-fins DON'T do well with toe-in. The added angle-of-attack created by toe-in causes cavitation on the inside foil, creating drag. Set these fins parallel to the centerline a la traditional fish.

Asymmetrically-foiled (curved on one side, flat on the other) can be toed-in up to 1/4" before the drag trade-off overwhelms the gains. Remember, "less toe = more go". Also, the more toe-in, the more the board needs to be turned across the trimline to generate speed.

In a quad set-up, use less toe-in on the rear fins than the front fins. Front 1/4", Rear 1/8" is common.

Vary fin size to match wave size AND rider size. Larger waves/heavier riders need larger fins.

Be prepared to experiment with fin template and fin size to dial-in the desired performance.

Re: Finned Xylem Paipo

Posted: Wed Apr 01, 2015 12:22 pm
by rodndtube
Great info in a nutshell... thanks!
nomastomas wrote:If you decide to use fins:

Symmetrically-foiled (foiled on both sides) rail-fins DON'T do well with toe-in. The added angle-of-attack created by toe-in causes cavitation on the inside foil, creating drag. Set these fins parallel to the centerline a la traditional fish.

Asymmetrically-foiled (curved on one side, flat on the other) can be toed-in up to 1/4" before the drag trade-off overwhelms the gains. Remember, "less toe = more go". Also, the more toe-in, the more the board needs to be turned across the trimline to generate speed.

In a quad set-up, use less toe-in on the rear fins than the front fins. Front 1/4", Rear 1/8" is common.

Vary fin size to match wave size AND rider size. Larger waves/heavier riders need larger fins.

Be prepared to experiment with fin template and fin size to dial-in the desired performance.

Re: Finned Xylem Paipo

Posted: Tue Apr 14, 2015 10:57 pm
by PhillyViking
Thanks for the great comments. I will definitely reset the toe in on the Xylem sides to parallel. I did try some asymetrical-foiled sides one day without benefit but the varied conditions make it hard to conclude. It will also be interesting to go back to finless or just minimal fin using just a nubster in the center. The Xylem just needs a little help in critical situations .. Its real easy to put too much fin on and get dragged down.

In the experimenting spirit, I now have two 4GF mats. The Omni for less than overhead and the narrower, thinner Lotus for bigger faster waves. The Lotus, especially with some extra pressure makes harder turns and sticks steeper waves provided you get your weight distributed to use the full length of the parallel rails. The Omni works best when glide is paramount.

Wish I had more time in the water!

Re: Finned Xylem Paipo

Posted: Wed Apr 15, 2015 3:06 pm
by flojo
just took my mat, 4gf roundtail out this morning-onshore winds, 4 ft, lots of closeouts and generally ugly conditions. Most of the long time regulars grumbling on the beach with their hard boards-I HAD A BLAST.

MATS ARE COOL