FIRST TEST RIDE: EPS vs Poly: a semi true to life test

General Discussion
21

“…something hard like skull.” Ha! maybe not so funny, just sounded funny for a moment.

You are experiencing the same things I did, and the same perceptions about rail volume.

I found the squirrelly aspect in the second half of turns to be one of the hardest things

to design out of the EPS boards. Wait for a day of committed 3 second bottom turns or

a full roundhouse cutback and you will see what I mean.

Excellent thread. Keep it coming.

Also, what was the surfing of the PU/PE like?

Lastly, maybe you should weigh the boards (is your scale digital?) to check on any gains

over time…

22

Yeah, it might not be the vehicle for a big thick day, but out of the box it seem enjoyable.

I didn’t comment on my poly board because it’s been my go to board since last year. So it’s like commenting on an old girlfriend. It’s comfortable, dependable, and you know your limits. The EPS thing is like dating a porn star, you don’t know what the next encounter could hold?!!

I need to weight it out on a digital scale now that I got the leash, fins, wax etc all stuck on it. I’ll keep track of it like Weight Watchers.

I actually creased some dude with the board today. It was one of those take off on a set wave, everybody is in front of you paddling out…cluelessly, then there is this guy instead of paddling towards the whitewater like a good little shortboard, he decides to race me to the pit/shoulder. Anyway I took off the back 12" of his board. Would have been a mess if it really was his skull.

-Jay

23

hey ben

its kinda pointless comparing firewire(which is sandwhich construction)

and plain eps/glass

they are a completely different animal

the reason sandwhich boards work better thinner

is that the stiffness of the board is exponential as the core gets thicker

im not sure of the exact numers

but a 3 inch board is roughly more than twice as stiff as as a 2 inch one

so with plain eps/glass

its just a normal surfboard construction

so going thicker isnt going to proportionaly stiffen the boards as much as with a sandwhich

not to mention that the blank of eps is prolly lower density and is more flexible anyway

this is a pretty vague and inacurate discription

but i think it gives you a fair idea

you cant put everything in the same basket

because it uses similar materials

like you cant bunch boards that use an epoxy resin all together

its misleading

wrt. thinner eps boards i really cant see it making that much difference

other then the foam is slighty more bouyant for the same volume

this could be regarded as an advantage!

although it could be harder to bury the rail for a lighter rider

so you would have to design for this

24

Thanks Silly, you hit the nail on the head!

Simple beam theory states that the stiffness increases by a cubic factor.

So,

if you doubled the thickness, (x2), stiffness goes up 8 times! (x2EXP3)

(this shows how sensitive stiffness and response is to dimensions)

Geometry is huge- but may be beyond the scope of this thread. That’s

what got us to the present trend in rail-stiffening structures…

Also, if you use stiffer skins, this drastically changes the flex and response.

And, very true but often overlooked, the lower density cores work better

in shear, which is a significant factor in simple (straight) bending.

(1lb EPS will promote more flex, composite skins reduce it).

25

yeah thats it George

times 8

i should know that one :slight_smile:

Quote:

Also, if you use stiffer skins, this drastically changes the flex and response.

And, very true but often overlooked, the lower density cores work better

in shear, which is a significant factor in simple (straight) bending.

(1lb EPS will promote more flex, composite skins reduce it).

which comes back to gregs 1 pound eps boards with huge amounts of 6 oz and heavy laps.

and using 1 pound foam in composites

Quote:

what got us to the present trend in rail-stiffening structures…

this is how i understand it so far

stiffening the rail also acts as a dampener (and reduces twist)

but it still alllows the core to move

so Ben

in a composite what your trying to achieve is a core that really moves

and skins that are nice and stiff!

if the skins are to thin along with a light core you end up with a noodle

if you use thicker skins etc.

the board can still really bend but the stiff skin makes it pop back quick

a centre stringer is for strength in a normal board

but

it also acts as a dampener , becuase it reduces core shear(apparently desirable aspect that gives pu/pe its feel)

also the foam itself is the largest factor that makes the controls the stiffness/flex

not the outer glass

i personaly think that any of these combinations to be valid and desirable for different riders in different conditions

the ride of a pupe feels nice

but I would want one thats well glassed to be ridden clean mellow conditions

i think a stringerd eps would come pretty close to the feel of pu/pe

if the foam was of high density

(ill get back to you all after i build a few)

in windy cross to onshore waves overhead i wopuld prefer my thick stiff composite

etc etc etc

26

Limitiabilities don’t know from the one surf, but I’m stoked on the first surf, feels like I’m a kid again surfing a 6’6".

Ah yes, this is what it’s all about!

I remember that moment very well.

Really good thread RH.

(porn star dating had me in stiches!)

27
Quote:

I found the squirrelly aspect in the second half of turns to be one of the hardest things

to design out of the EPS boards

I’d be interested to hear how you design out the squirrel Plus1. This is something I noticed on my compsand - even with though its got thinner harder rails than a PU/PE shape. Maybe I need to go much thinner and harder on the rails for the next one. I did move the cluster back and put in bigger sides which helped quite a bit.

I’ve kind of adjusted my technique to compensate. A heavier (PU/PE) board has momentum that you learn to flow with in cutbacks and long bottom turns. I’ve found with going to a super light board you have to modify your technique - bottom turns are different but you learn to like it, because the lightness can get you back up the face quicker which is a plus, but for long bottom turns - you have stick in a pump at the bottom of the turn. Cutties at first feel like you are fading as you come around - you can’t just set the rail and let the inertia swing you back around. The interia has to come from your own weight - you have to weight the rail in the second half of the turn - its hard to explain but I’m starting to feel the rail more through my feet and use my thighs more to power the turn.

The big plus with compsands is your top turns - when you get used to them you can really do big hacks on the face, I think you get more feel in the rail and you can make slight adjustments mid turn that you can’t do with a heavier PU/PE.

28

thanks Paul for those explanations !

I definately would like to ride some of them .

"

The EPS thing is like dating a porn star, you don’t know what the next encounter could hold?!! "

maybe we should ask “plusone” …(or , by the looks of your avatar mate … maybe that should be “plus two” , eh ?)

geez George…it must get HARD sometimes , being a successful shaper , eh ? [especially when , by the look of the photo , she can’t let go of your planer !]

…it’s almost enough to make you shape too much concave into the bottom [of the board] or something …

29

it’s not my board

30

nothing really to do with this thread,

but just for the record,

i like epoxy boards HEAVY. not traditional log heavy, but heavy enough to glide and swing like a pendelum on bottom turns, all that stuff.

in my opinion, epoxy IS great for achieving this, because you can glass it extra heavy, making the board almost bulletproof so it will last for many many years, and still get the glide.

really light surfboards are like a skipping record, to me.

to me.

31

do you mean epoxy resin over pu

or epoxy resin over eps

or epoxy resin as used in sandwhich construction over eps

etc etc etc

32

Thank’s Pinhead for that eloquent and simple explanation.

That’s it in a nutshell…

Boards made from these new materials will require a slightly different technique inorder to maximize their potential.

They will never ride “like a poly” if they are to make the next leap in performance.

Pros and high performance surfers will be able to make these adjustments very easily. The average joe-blow weekender not so easily especially if they are switching back and forth between heavy polys and a compsand.

I think if you make a commitment to this design and lighter weight then your overall approach will be much faster with alot more arcs in smaller spaces because of the weight reduction. At high speeds there still may be a chatter and lifting problem as the air gets under it in a high speed trim but a techique using continous rail to rail movement like better surfers do eliminates that. Once someone can tie in unlimited accelleration from the fins with the extreme light weight and flex snap then this will really blow up big time. Board shapes and fin configuations will evolve into something we haven’t yet seen…

I predict much bigger airs and more floating type moves like windsurfers get over huge white water sections as guys really lock in to the potential of the new designs… Theres’s a potential to possibly ride over the top of broken whitewater instead of down infront of it once guys figure out how to control these boards up there.

Things are going to get real interesting…

33

Ok so I just got back from the North Shore and had probably the best run of waves ever, Oct 6th-16th. No winds, sunny, 4-9ft almost every day. Surfed Lani’s 2x oh, surfed Sunset 2 x oh, surfed Sliva Channels 1.5-2x oh,Changes Day Star, Hammer heads. all in epic conditions. Surfed Jockos out of control 2x oh, Rocky Rights 2x oh. And of course Turtle bay.

So my verdict is in on the epoxy thing. 1) more weight is needed in larger surf, especially Hawaiian waves. My next board will be made of 2.5 to 3 lb styro. and 3 x 6 glass top 2 x6 bottom. The flex thing with the PVC stringer was great, lot’s of projection but scary on bigger Sunset. This is probably due to my shriveling up gonads in the eye of the beast. The board definately had a sweet spot / spring / torque thing going on. find it fast, great ride. Find it late, (lanis) get thumped. The Poly board was more forgiving…just stand up and go… But I’m still sold on the epoxy thing.

So durability…ripped on fin box out 3 wks ago, then broke the epoxy board Oct 15th after 9 days of 2 a days of solid NS duty. The Poly board has survived 2 tours of duty on the NS plus one winter in So Cal, and is still going strong.

Verdict. Make another Epoxy board with more glass. It will still be super light weight…but I need to make it more durable. Hopefully the additional weight / less flex won’t kill the “feeling”

The feeling verdict. After getting a bunch of days on the epoxy board, my concern was that i was going to have to nurse it in a 2 stage turn on bigger waves, you know kind of pump turn at the top then drop in to the bottom…but thats not true, towards the end of its life I was pushing it as hard as an old 40 year old guy can. Everything felt fine and solid. Actually the board broke / buckled on a bottom turn. The buckle came at the same place I smashed my knee into the rail / deck earlier in the week and created a small rail slice. So it broke on the weakest part of the rail. Bummer… Also, I had done a fair amount of damage on the tail deck and front foot area. But this compression is only that…compression, there is no delam, and it seemed that the compression stopped after the 2nd week of surfing.

I let a few of my NS buddies ride ride both boards, and everyone liked the epoxy better. Actually if it wasn’t for the broken board syndrome the epoxy would still be living on the NS…my buddy wasn’t going to let me take it home.

Time for epoxy board number 2…the journey continues. Durability or performance…walk the fine line

-Jay


34

Hey not all us big guys ride huge boards I have a 7’4" 2.80 thick in the stringer but the rail is very pinched!

35

Very informative and also impressive. Very envious of the epic ‘test conditions’ as so much is to

be learned. Keep the info flowing.

36

Just a few more lessons.

  1. Clear boards are slower than boards with color. Next board will have color.

  2. Clean waves will make buckled water heavy board still surf better than any other board tested to date

Next board: the 7’7" short board, and the 9’0" California gun test.