dream custom

[CarvCanada]

What's your dream custom that you would have built if you had 2000 dollars strictly to be spent on a snowboard? :)


Mine would be (and eventually will be :) )

Prior WCR

181, 14m radius, 2mm taper, 21.5cm waist
with the super snappy quadraxle carbon glass




come on snow come one!

[Mike T]

I have a Coiler on order that is going to be a lot less than $2000 that I am pretty excited about.

The purpose of this board is to carve in spring conditions; I'll call it the SlushBuster or something to that effect. It's sort of a cross between a AM and a Race Carve II 180:

Length: 180
Edge: 157
Sidecut: 12.7
Waist: 19.5

The flex pattern will be all-mountain; the stiffer nose will allow me to opush it a little harder on the slush. I picked the sidecut based on wanting it "just a hair righter than the PR 184". I added 1.5 cm of extra width to my "hardpack ideal" of 18 cm, which will come in handy when railing through slush and corn, and also give it a little more "buoyancy" if I want to take if off the groomed. I chose the edge length based on wanting more stability than my Axis 172, but didn't feel the need to go too much longer because the AM design's stiffer nose and tail will provide some additional stability on the softer stuff as well. I also plan to use it in mid-winter after say 4 inches of fresh, when the groomers are on the soft side at Mt Hood but there's no enough snow off the groomed to make it a real powder day.

I guess I don't have enough experience or knowledge about materials to conjure up a $2000 project! The SlushBuster concept was born from riding two boards that I really like in spring conditions and trying to combine the best of both of them into a single board. I hope it works :)

[Neil Gendzwill]

Is it even possible to spend $2000? I think if you add up all the options at any of our fave 3 boutique builders it comes to less than 2 grand.

I've just got a stock 'ol AM172 on order. Looking forward to it.

[bobdea]

maybe get some input from JG and do something similar to a madd but longer 185-190, wider 19.5 or 20 sidecut 15 and put a bit of a tail on it I do ride switch and when its soft with a flat tail you know what happens
materials of course would have to be the best

another idea would be a giant split tail around 205 or so 19.5 waist 17m sidecut and super stiff
I always liked the feel of the burners but why not go to the next level

[AlpentalRider]

I'd get a custom built SWOARD specifically for my body, with built in HEAD Intelligence dampening technology. Except I'd add the ability to manually control the stiffness in the HEAD system via a remote, instead of just being an active response system.

[NateW]

Very thin core, for light weight. Then to get the stiffness back up, no fiberglass - use carbon fiber and/or kevlar instead.

Anyone know if that would actually work? :)

[Donek]

Shear flow through the core is a function of thickness. If you maintain the same thickness, yet thin the core up, the shear stresses increase. It's actually a cubic function. You start to excede the fatigue limit of the core very rapidly. If you've heard of a board turning to a noodle within 20 to 50 days, this is most likely the reason. The manufacturer has thinned the core too much and used too stiff a reenforcing laminate. This results in a wood core that becomes much like a tooth pick after you've chewed on it for an hour. There's not much structure left in the core.

If you look at the elastic curve of carbon fiber, you'll find it's strain to failure is very short. In other words, it doesn't stretch very far before it breaks (it takes a lot of force to get there). The result of using such a material involves a need to sustain larger amounts of shear strain within the core in order to achieve the same stiffness obtained with a more elastic laminate such as fiberglass. This results in the problem indicated above. The fatigue limit is exceded and the core breaks down very rapidly. The use of carbon fiber in a very stiff device not intended to bend is advisable. A snowboard bends too much for carbon fiber to be an effective or advisable solution.

[Chris Houghton]

Chris built that board for me last March, except it's an 18cm waist. Also picked up the Donek 180/14/18.5 equivalent, can't wait for the snow to get here so I can do some comparo runs. You're right, the new quadraxle glass is real snappy, unbelievable torsional stiffness.

[~tb]

Quick question to someone that might know better than I . . . which means, most of you, but maybe sean could shed some light.

Plain weave glass or carbon has fibers running at 0 and 90 degrees. the fibers running at 0 degrees down the length of the board would stiffen the board tip to tail, but do nothing for torsional stiffness. . . The fibres going across the board are just wasted weight and money right or wrong?

Triaxel glass or carbon has fibers running at 0, 45 and 135 degrees. the fibers running the length of the board stiffen the length wise flex, and the fibers at 45 and 135 stiffen the board torsionaly as well as adding somewhat to the length wise flex of the board. . . There are no fibers running straight across the board as they are relatively useless.

Now there is quadraxel glass and carbon available, and being used ins snowboards. This would give you fiber orientations of 0, 45, 90 and 135. Doesnt this glass just end up adding dead wieght to a board compared to the Triaxel glass? The fibers that were added are running across the board in a direction that most likely the boards are pleanty stiff as is.

Please someone share your thoughts.

Oh, and my ideal custom . . . Sean made me the 195 that was absolutely sick about 4 years ago now. It has since met its maker, and I would love to get a new one. . . but with $2000 to blow, I would also ask him to take a stab at an independant flex plate to work with that board that would stiffen the board between the feet, and just infront of the bindings when I wanted to use it. Many manufacturers have been reluctant to go this route as it has been shown that the plate would basically cost as much as a second board . . . but with $2000, thats ok.

-Todd

-Todd

[Jack Michaud]

Originally posted by Donek
(snip) A snowboard bends too much for carbon fiber to be an effective or advisable solution.

I thought this is exactly what Madd is doing....? Making a thinner board reenforced with carbon fiber? And people seem to enjoy riding them. I've never owned one, but I've heard of them lasting a long time..........? Any idea what's going on there?

[Jack Michaud]

Originally posted by ~tb
Plain weave glass or carbon has fibers running at 0 and 90 degrees. the fibers running at 0 degrees down the length of the board would stiffen the board tip to tail, but do nothing for torsional stiffness. . . The fibres going across the board are just wasted weight and money, right or wrong?


I don't think so. It is true that torsion is strongest along the 45, but I'm pretty sure it also has components at 0 and 90 degrees and everywhere in between. 0/90 fibers resist some of it, as well as out-of-plane displacement.


Now there is quadraxel glass and carbon available, and being used ins snowboards. This would give you fiber orientations of 0, 45, 90 and 135. Doesnt this glass just end up adding dead wieght to a board compared to the Triaxel glass? The fibers that were added are running across the board in a direction that most likely the boards are pleanty stiff as is.

As reasoned above, I don't think the fibers running across the board are dead weight. However, Prior's quadraxle glass is 0,90,30,150. http://www.priorsnowboards.com/board_construction_wcr.php
(they call the lengthwise direction 90 degrees) I don't know why it wouldn't have fibers running along the 45s. Anyone?

Oh, my ideal custom - there are so many custom shapes out there, I don't feel the need to make a new one. But I'd want something tuned to my exact weight, and with a shiney metallic silver topsheet so I can be just like Shred Gruumer!

[bobdea]

a split donek similar to a sasquatch but with a 27 waist and a little softer
the length about 175 basicly a board to access the trees that will still perform anywhere else I go too

a split swallow tail would be cool too that would be around 200 with a 27 waist and a shallower sidecut for highspeed powder runs


I really love the powder but only in softies though I do have to say if its wet enough my old FPs 178 and 18? were good in that stuff
about four years ago it was powder day and I was out riding and I blew by a bunch of racers that were just standing around later that day their coach who I knew pretty well was saying thats as fast he had ever seen anyone go on a snowboard and still turn

[mikko]

OK. So I'm currently studying polymer composites. I guess I should have some info to share.

The longtitudinal fibers strenghten the board lenghtwise, but as they take the load (when the board is bending) they also create a small force perpendicular to the board. This is why 0 angle fibers exist. This was extremely simplified version of what is happening in such a complex system as a composite.

Anyhow I can tell you that all the fibre directions have a reason to exist, since fibers (in all these directions) influence one another. Now we've been taught that the optimal torsional stiffness is found when the angle is 30/150 degrees. So looks like to me that the guys at Prior know what they're doing.


Heh. My dream custom is definately the board I'm dreaming of making someday myself. If I could ride that thing down the hill for only one time. It would be too sweet. :D

[Jack Michaud]

Originally posted by mikko
Now we've been taught that the optimal torsional stiffness is found when the angle is 30/150 degrees.

can you elaborate on why this is?

[mikko]

Well. That's the tricky part. There is no simple explanation or even a reasonable way to calculate that. Basicly, it's all about testing, testing and a little more testing. As I mentioned before there's a whole lot of interaction going on with the different fiber directions, which make it pretty hard to figure out just why 30/150.


There are mathematic models that can be used but in the end they are also based on experimental results. Because the mathematics in these models is really, really complex, I will not go any further into it. (Although I'm not that advanced that I even could, if I wanted.) :rolleyes:

[Donek]

Originally posted by mikko
Well. That's the tricky part. There is no simple explanation or even a reasonable way to calculate that. Basicly, it's all about testing, testing and a little more testing. As I mentioned before there's a whole lot of interaction going on with the different fiber directions, which make it pretty hard to figure out just why 30/150.

Mikko,

I'd be very interested to know what text your class is using. I just performed a plate theory analysis on such a laminate and it predicts a 25% decrease in torsional rigidity. Is this based on a bulk modulus model? have the results been duplicated in more than one lab with samples produced in different manufacturing facilities? Back in the 70's, it was believed that fiberglass was much weaker in compression than tension. It turned out that this was based on testing that allowed buckling failure within the fibers. When properly supported, the glass held up in compression almost as well as in tension. I'm very curious about these results and where they have come from. Please let me know your sources.

Thanks

[Donek]

Originally posted by ~tb

Now there is quadraxel glass and carbon available, and being used ins snowboards. This would give you fiber orientations of 0, 45, 90 and 135. Doesnt this glass just end up adding dead wieght to a board compared to the Triaxel glass? The fibers that were added are running across the board in a direction that most likely the boards are pleanty stiff as is.
-Todd

Todd,

When you have an equal weight of fibers, distributed evenly through 360 degress, it produces in plane isotropic behavior. This quadraxial laminate you describe is doing exactly that. If you're familiar with Volant's product, you'd have read that the isotropic behavior of the steel is what made their skis so torsionally rigid. An in plane isotropic composite laminate would in theory generate very similar results.

Using a plate theory analysis, a 90 degree fiber contributes nothing to torsional rigidity. From a weight point of view, a 0, 60, -60 laminate might be more effective. If you drop below 3 directions, the in plane isotropic behavior doesn't apply. In other words a 0, 90 laminate will not produce the same results.

[Donek]

Originally posted by Jack Michaud
I thought this is exactly what Madd is doing....? Making a thinner board reenforced with carbon fiber? And people seem to enjoy riding them. I've never owned one, but I've heard of them lasting a long time..........? Any idea what's going on there?

I've only looked at a couple Madds, so I can't be certain, but I believe that isn't exactly what they are doing. The core board is mostly glass and wood. The carbon fiber is just the butterfly shaped plate. I didn't design the board, so I'm not certain, but I'm pretty sure they are using destructive interference between the plate and the board to dampen vibrations. Essentially this means you have 2 devices with differing natural frequencies. When they vibrate against each other, some of the peaks collide and essentially destroy each other. If you're a musician, you'd be familiar with this when you are tuning. The pulsing you hear between two untuned notes is destructive interference. I think their design actually incorporates a viscoelastic material between the plate and the board to act as a dashpot. This provides even further dampening when the the peaks are not coliding, but moving away from each other, by generating an apposing force to the movement.

[mikko]

ah. I kinda waited for someone wise enough would come and clarify things more. I'm no expert in this. Yet. :D


Sean,

I'll send you some email.



mikko

[D-Sub]

Originally posted by Donek
If you're a musician, you'd be familiar with this when you are tuning. The pulsing you hear between two untuned notes is destructive interference. I think their design actually incorporates a viscoelastic material between the plate and the board to act as a dashpot. This provides even further dampening when the the peaks are not coliding, but moving away from each other, by generating an apposing force to the movement.

heh. phase cancellation. another studio term

[Jack Michaud]

Originally posted by Donek
When you have an equal weight of fibers, distributed evenly through 360 degress, it produces in plane isotropic behavior. This quadraxial laminate you describe is doing exactly that. If you're familiar with Volant's product, you'd have read that the isotropic behavior of the steel is what made their skis so torsionally rigid. An in plane isotropic composite laminate would in theory generate very similar results.

Using a plate theory analysis, a 90 degree fiber contributes nothing to torsional rigidity.


These two statements appear to be contradictory.......? So is the 90 degree fiber (across the board) simply along for the ride? Is quadraxle glass a gimmick?



From a weight point of view, a 0, 60, -60 laminate might be more effective.

Did you mean to say 0, 45, -45? I thought from your other post you weren't a believer in the 60/-60 (or 30/-30) fibers?

BTW, this is really cool stuff, thanks for sharing.

[mikko]

Originally posted by Donek
I didn't design the board, so I'm not certain, but I'm pretty sure they are using destructive interference between the plate and the board to dampen vibrations. Essentially this means you have 2 devices with differing natural frequencies. When they vibrate against each other, some of the peaks collide and essentially destroy each other. If you're a musician, you'd be familiar with this when you are tuning. The pulsing you hear between two untuned notes is destructive interference.

Board vibrates -> use a "microphone" of some sort to record the vibration -> invert the given wave function -> use some sort of "loudspeaker" to transmit the negative vibration into the board -> do it all in real-time

That way we should have a board that does not vibrate at all. ???
:p

The same principle as in some headphones, that simultaneously record, invert and play the surrounding noise. This cancels the surronding noises and all you hear is that what you want to hear. D-Sub probably knows the right name for these gadgets. :confused:

Now I'm just throwing around ridiculous ideas. :D

[Jack Michaud]

Originally posted by mikko

The same principle as in some headphones, that simultaneously record, invert and play the surrounding noise. This cancels the surronding noises and all you hear is that what you want to hear. D-Sub probably knows the right name for these gadgets.


Hmm, where could I get some of those........ Todd?? ;)

[mikko]

Originally posted by Jack Michaud
These two statements appear to be contradictory.......? So is the 90 degree fiber (across the board) simply along for the ride? Is quadraxle glass a gimmick?

notice that Sean wrote:
"90 degree fiber contributes nothing to torsional rigidity"


EDIT: 90 degree fiber does influence the composite in general, but how?

I'm a bit out of my league here so I'll leave this to Sean for now.

[Vahur]

Originally posted by Jack Michaud
Hmm, where could I get some of those..
Google for noice cancelling headphone, you'll find enough products by this buzzword.
I personally prefer to record silence and then play it down with amp's volume turned to the maximum in order to avoid sounds which I don't want to hear :D

[mirror70]

My dream custom would have a holographic projector on it which would project an image of someone trying to carve but doing it really really really badly - that way, when people see me riding nearby, I'll actually look competent (ha!).

The women will be all up onz.

[NateW]

Sean, I had to read your post about shear twice before it clicked. Thanks for writing that up.

[NateW]

Sean wrote: From a weight point of view, a 0, 60, -60 laminate might be more effective.

Then Jack wrote: Did you mean to say 0, 45, -45? I thought from your other post you weren't a believer in the 60/-60 (or 30/-30) fibers?

So Nate writes: 0 / 45 / -45 wouldn't give equal distribution in all directions, so wouldn't produce the in plane isotropic behavior he was talking about. 0 / 60 / -60 would, it's all laid out in equilateral triangles.

Sean, what does your plate theory analysis say about 0 / 45 / -45 compared to 0 / 60 / -60?

Or were you saying that your analysis doesn't model the isotropic behavior? I'm not sure what to make of your statement that "Using a plate theory analysis, a 90 degree fiber contributes nothing to torsional rigidity."

And Jack said: BTW, this is really cool stuff, thanks for sharing.

And Nate says: What Jack said.

[Jack Michaud]

Originally posted by Vahur
Google for noice cancelling headphone,

That was a joke, Todd works for Bose.

[Jack Michaud]

Originally posted by NateW
Sean wrote: From a weight point of view, a 0, 60, -60 laminate might be more effective.

Then Jack wrote: Did you mean to say 0, 45, -45? I thought from your other post you weren't a believer in the 60/-60 (or 30/-30) fibers?

So Nate writes: 0 / 45 / -45 wouldn't give equal distribution in all directions, so wouldn't produce the in plane isotropic behavior he was talking about. 0 / 60 / -60 would, it's all laid out in equilateral triangles.


Oohhhhhh yeah. equilateral triangles, of course. However, I'm still interested to know <i>why</i> Prior's quadrax is 0,90,30,-30.

[Donek]

First off, I'm no professor. I'll do my best to clarify things.

When I talked about 0,45,-45, 90 laminates and then said the 90 degree contributed nothing to torsional rigidity, I was talking about 2 different concepts. The eaqualy spaced lamintes apply to in plane isotropic laminate. In theory, that laminate could be rotated 12.34 degrees (or any arbitrary number) and produce the exact same results as if it were not rotated. That is in essence the definition of isotropic behavior. The 90 degree comment was simply refering to the question regarding 90 degree fibers contributing to torsional rigidiy. Plate theory prdicts no contribution to torsional stiffness.

There is an interesting side note to plate theory. It is much like beam theory in that it assumes small deflextions in the material. To my recollection, it never defines the term small.

Getting back to the how the 90 degree fiber influences the composite. It builds stiffness side to side in the board. It could, therefore be used to assist in the so called "energy transfer" to the edge. The other thing to consider is that a board rarely sees a pure twisting force or a pure flexing force. It is conceivable that in the situation where the board is loaded at the tip during turn initiation, the bending force is not in a 0 deg direction, but at some angle to 0 degrees. One could say that in that situation, the 90 degree fiber is contributing in some small way to the stiffness (both torsionally, and in bending). To me, this begins to get a bit cumbersome. At some point, it becomes necessary to simplify the model and rely on what can be calculated and believe in the riders ability to compensate for what can not. To me 90 degree fibers seem useless for the most part. Their contribution to the needed stiffness is so small that they are unnecessary.

Nate asked about the prediction for the 0, 60, -60 laminate. It's important to first note that in standard constructions for snowboards there are a lot more fibers in the 0 direction than in the +- 45. If I leave the volumes the same, plate theory predicts a 16% decreace in torsional rigidity. If we go with equal fiber distributions, there is a 6% increase in torsional rigidity and a 12% decrease in longitudinal stiffness.

I hope I was clear enough and got all the questions. Excuse my engineering approach to spelling.

[mirror70]

Sean,

It seems that you're using a simple plate model and not a laminate model. is this correct? An important distinction between the two is that the laminate model takes in to account the warp's ability to stabilize the weft, and vice-versa.

[Donek]

Originally posted by mirror70
Sean,

It seems that you're using a simple plate model and not a laminate model. is this correct? An important distinction between the two is that the laminate model takes in to account the warp's ability to stabilize the weft, and vice-versa.

Given all the matrices, I wouldn't consider it too simple. I have the ability to build a laminate stack of any composition. I'm using an excel model I wrote in College that was verified against a commercial program called Utah Laminates. I suppose that there could be a problem with it, but I've used it on 3 separate occaisions to verify other programs I've writteno similar sorts of work and always been able to get the same results. I believe there is now a freeware program I found online. I'll check it against that this evening. Perhaps you can explain simple plate vs a laminate model. The text I'm using doesn't seem to refer to these terms. I'm using Jones "Mecahnics of Composite Materials".

[skeez rule]

but with more carbon fibre and a topsheet with all sorts of tech things on it like lights and terms like "high performace skid theory" on it
a onepiece to match them with tassles on it like Billy Kidd wears

[slopetool]

Skeez! we missed you- thanks for piping in again!
You rule the slopes!

[chillaxin.nl]

That's an easy one: Tomahawk or Virus custom!