lowrider Posted August 21, 2016 Report Share Posted August 21, 2016 To paraphrase ( It's not so much the tool but the tool riding the tool that needs attention ) Quote Link to comment Share on other sites More sharing options...
philw Posted August 21, 2016 Report Share Posted August 21, 2016 Considering it's warm outside, I'll disagree somewhat with that. I rode glass boards for years, then one day I put on a metal Kessler SL. The first mogul slope I hit, I crashed and burned big time... because I was riding significantly faster than I thought I was. The better damping of the metal board made higher speeds feel slower. I'd say that's probably why they use them to win races. -- The Rossi thing was marketed as "VAS" (Vibration Absorption System) over here, against the Dynastar red blobs. I don't recall either being significant/ game changers. Metal snowboards are. I would suggest that the reason is that the rubber laminate throughout is a much bigger effect than some external dampener, which I don't find very satisfactory from an engineering perspective (rather like the ST, to me that's inelegant). -- Quote in order to make a carved turn, a board needs to bend, but it does not need to twist. ... Getting back to snowboarding, consider that in order to make a carved turn, a board needs to bend, but it does not need to twist. (That ski performance improved when they became torsionally stiffer should make this point obvious.) When a board twists while in a full engagement turn, one end of the board is essentially trying to make a turn of different characteristic than the other end. This generates a dissonant waveform, and if the frequency and amplitude are significant, the rider can get ’chucked’ out of the turn. If you lower the resonant frequency, that same rider twisting the board to the same extent can essentially ‘hide’ between the wave peaks long enough to reach the effective ‘end’ of that particular turn. This is evident by the tracks left behind, and also from what one can observe in real time. If a rider can figure out how not to twist their sled, they can be assured of a smoother ride, material composition notwithstanding. I can't understand where waves come into it. We're just talking about the three dimensional stability of a structure. I think I want my board to have torsional stiffness so I can crank it over to a consistent edge angle. People riding soft boot boards at speed would maybe know what happens if it's not stiff, but then their stances are different and that may compensate for the effect.There are other threads to argue this point I believe. ---- I would be more interested in a board which could combine the general stability of a modern metal board with the aggressive kick of an old school glass board. I'd be wanting rubber to damp those high speed jitters, but when I kick it hard I'd want it to kick back. Perhaps those things are contradictory, or perhaps you could do it with materials or construction which reacted differently to those two types of load... there's the rub: I'm not sure how the board would "know" which sort of load it was receiving. Perhaps the best you can do is compromise: response versus stability. Quote Link to comment Share on other sites More sharing options...
Corey Posted August 22, 2016 Report Share Posted August 22, 2016 12 hours ago, philw said: I would be more interested in a board which could combine the general stability of a modern metal board with the aggressive kick of an old school glass board. I'd be wanting rubber to damp those high speed jitters, but when I kick it hard I'd want it to kick back. A Donek Proteus achieves that goal quite nicely. It's buttery smooth if you're gentle, but it can give an exciting pop at the end of the turn if you finish with lots of weight on the tail. Coiler can do the same if you ask for it. Quote Link to comment Share on other sites More sharing options...
Shred Gruumer Posted August 30, 2016 Report Share Posted August 30, 2016 Oxess, with lots of rubber..! Works.! You can stick your hand up a cows ass to check for a good T-bone but I would rather take the butchers word for it. like I like my women , two creams and sugar... what does it mean... I have no idea... but there sure is a lot off talking going on.. and not enough building! RSS Quote Link to comment Share on other sites More sharing options...
CMC Posted August 30, 2016 Report Share Posted August 30, 2016 One of the things that made The Madd so successful was its dual flex pattern. Torsional twist is important, tuning it to where it works is another ball game. Quote Link to comment Share on other sites More sharing options...
Tanglefoot Posted August 31, 2016 Author Report Share Posted August 31, 2016 On 30 Aug 2016 at 3:17 PM, Shred Gruumer said: Oxess, with lots of rubber..! Works.! You can stick your hand up a cows ass to check for a good T-bone but I would rather take the butchers word for it. like I like my women , two creams and sugar... what does it mean... I have no idea... but there sure is a lot off talking going on.. and not enough building! RSS Shred Gruumer, I don't know what you are taking, but please send some over to Norway so I can try it as well. Now Oxess is an interesting one, I think I have heard mention of their capabilities before. Hard to figure anything out from their website though - they seem to advertise Titanal construction for their high performance boards. Have you been able to compare their carbon boards with their Titanal boards? And just to add another couple of minks to the menagerie: My wife has recently taken delivery of an F2 Eliminator Carbon, which apparently has a "Torsion oriented X45 trial carbon". Upon closer inspection, this is not the case. It seems to have a glass fibre layer next to the core, presumably triaxial, and a woven 0/90 carbon fabric on top of this. This is structural nonsense and seems to be a marketing exercise more than anything else. She also owns a Kessler Cross of the same length, width and intended purpose, so I should be able to carry out a useful comparison here. I just need to wait for her to leave the house before taking the bindings off and performing the structural tests. I also intend to look at the board edges under a microscope to see what is really going on there. I think the Kessler is much heavier than the F2, but again, I need the wife to leave the house so I can borrow the kitchen scales. Wish me luck Quote Link to comment Share on other sites More sharing options...
pow4ever Posted September 1, 2016 Report Share Posted September 1, 2016 I have been lurking and watching this thread. checking if OP is still alive? lol Did the wife caught you "stealing her board" and mess up the kitchen scale? Marcel from Oxess send me the following: "Boards with Titanal and carbon are a bit more damped, a bit less powerfull. Carbon boards without titanal are more powerfull, a bit less damped.It depends on the riding style, for carving I like the carbon boards a lot.All our boards are available with carbon or carbon/titanal construction. The difference at the board types is the width. WXR 210mm, RXR184mm and XXR 164mm." Engineering is all about compromise: Filter out the "bad noise" but still be responsive and FUN is key to me. Thread on metal you might find interesting: 1 Quote Link to comment Share on other sites More sharing options...
Tanglefoot Posted September 6, 2016 Author Report Share Posted September 6, 2016 Thanks pow4ever - it is beginning to dawn on me that a lot of people are thinking about this already. With regards to Oxess: I am wondering whether the addition of Titanal to a carbon board will mainly add mass, and therefore lower the natural frequencies. This could easily be mistaken for more damping. If there is already carbon in the structure, the carbon will be the stiffest load path, and the Titanal may not do much work. Hard to tell what's doing what though, when different materials are combined in this manner. Interestingly, neither Oxess, Kessler or SG quote the weight of their boards on their web pages. Is this because some of them are surprisingly heavy? On a different note, I've been trying to find suppliers of viscoelastic materials for constrained layer damping, but with limited success - I have mostly come up with self adhesive sheets for acoustic applications. However, I have found one material that is intended for co-curing with composites, and that comes in snowboard-size rolls and two thicknesses. The product is called "Smacwrap Veil ST", it is meant to work well in the snowboarding temperature range, and there is some info on this web site: http://www.smac-sas.com/wp-content/uploads/2014/04/SMACWRAP-VEIL.pdf I have no experience with this product, and I don't know if you could even come close to an answer without building a prototype. 3M also have a range of products, but I am not sure if they can be co-cured, and they seem to be intended for higher temperatures. Quite a bit of technical info here though: http://multimedia.3m.com/mws/media/828134O/3mtm-viscoelastic-damping-polymers-112-130.pdf?fn=Viscoelastic Damping Polymers 11 Quote Link to comment Share on other sites More sharing options...
Tanglefoot Posted September 14, 2016 Author Report Share Posted September 14, 2016 Right then. The lady of the house decided on a trip to IKEA this evening, so I managed to borrow the kitchen scales and both of her boards for long enough to make some useful measurements. I also found a vibration analysis app for my phone, which absolutely made my day, being a nerd and all. So - the wife owns two boardercross type boards; a Kessler Cross 153 and an F2 Eliminator Carbon 153. On first impression, very similar in terms of length, width, sidecut etc. I measured everything that I could sensibly measure, and everything that I thought was relevant for edge hold. Torsional damping and torsional frequencies are highly relevant, but I couldn't figure out a good way of measuring these. This is what I found though, and I am using the Kessler as a base line here: F2 Mass: 13% lighter than Kessler (2862g vs 3286 g) F2 Bending stiffness: 7.3% stiffer than Kessler F2 Torsional stiffness: 24% softer than Kessler F2 Bending frequency: 8.8% higher than Kessler (9.8 Hz vs 9.0 Hz) F2 Bending damping: 33% faster than Kessler (4 s vs 6 s) I don't know what to make of these numbers, but I am confident the edge hold community is here to help. The two big surprises for me were the difference in torsional stiffness, and how much quicker the F2 damped out a similar shock. Another interesting observation is that the carbon Eliminator has a thick, clear topsheet, which is absent on the glass Eliminator. So much for the analysis; the next logical step is to compare the on-slope behaviour. I feel there are two main options: A: I dress up as a welterweight female, and borrow both of the boards for a back-to back test at the first sign of ice on the slopes. B: Sometime in the spring, I ask my wife what she thought of the boards. I'll keep you posted. Quote Link to comment Share on other sites More sharing options...
BlueB Posted September 15, 2016 Report Share Posted September 15, 2016 Fantastic work, thank you! Yes, lighter but stiffer board would stop oscillating sooner. However, it would also rebound quicker and more. On the other hand, the board with more mass would dampen the vibration caused by terrain texture, more efficient. I can put my head on the block that Kessler will have more edge hold for DESIGNED rider weight. You'll have to rely on your wife's feedback for high speed ride, or if yourself, ride at lower speed and pitch. I had (RIP) a noodly board that had mega hold, but not at high speed at all.... Good luck and keep us posted! Quote Link to comment Share on other sites More sharing options...
Tanglefoot Posted September 15, 2016 Author Report Share Posted September 15, 2016 BlueB, thanks for your feedback. Everything I have learned in life also points towards the Kessler as the grippier board, but I am not sure which of the measurements show this - if any. I would also love to map some boards that are more relevant to freecarving and to my own weight range, but since I am not measuring to any known standards, I need two very similar boards, made with different materials, for the work to be meaningful. Could this be my excuse to buy another board? Quote Link to comment Share on other sites More sharing options...
Corey Posted September 15, 2016 Report Share Posted September 15, 2016 It's easy to vary weight: Get some stick on wheel weights from your local tire store. Sean mentioned once that he tried lighter Rev boards but the pros didn't like it. The big problem with self-testing is the placebo effect. Better to have a buddy make a change in a manner that you can't tell what they did. We all think that we're too smart to fall victim to it but we're really not. If you have an unmeasurable/subjective effect that you're trying to prove, you'll almost always feel that you've proved it. Quote Link to comment Share on other sites More sharing options...
BLOODTYPEZX10R Posted October 13, 2016 Report Share Posted October 13, 2016 On 8/16/2016 at 8:44 AM, b0ardski said: Mark Miller of Thirst snowboards has managed to create non metal boards with amazing dampness. His boards are heavy, but so is a Cadillac and the ride is similar. I do think overall weight is an often overlooked factor in a boards dampened trackability, not a determining factor but contributing one. When I demoed the Thirst X7 the weight and apparent extreme stiffness (thick core, lots of carbon) scared me off a bit, but the totally intuitive, predictable, chop and rut proof Cadillac ride was a pleasure at fast or slow speeds unlike the Identity carbon 185gs that needs speed to come alive. in short, I do believe tanglefoot is right, dampness is not necessarily metal dependent. I am Mark of Thirst snowboards, thank you Troy for the mention. I have researched ski and snowboard construction for years now and have not found one single company that has taken advantage of the main component...the core. I have been designing and building boards now for 37 years and have always built my cores differently. I create my cores using as few as 14 to more than 30 separate components. The board that Boardski mentions is the 7X. It has a asymmetrical core construction (for regular and Boardski rides goofy) and is a 179 all mountain design. The 7X has a carbon stack consumable above the edge and is hybrid in final assembly in that it is vacuum bagged but also pressed. As far as weight comparative to a board of the same length it has a waist that is 20.3 and shovel of 26.5, so it is fairly wide; hence the all mountain. I have since moved from the hybrid construction and carbon stack, it is too time consuming. I don't think that the comparison of my board to a Cadillac is quite fair. It is very responsive, easy to ride and extremely stable, not to mention fast. It loves very hard snow, rides great in powder and busts through chop, crud and slush. This board was my preference no matter what the conditions, but it is retired now and I have moved on to even greater designs and ideas to please my ever illusive customer. Thirst is on FB and you can find a link to my website there. UMUSTCARVE has some video from a few years ago on youtube you can check out. Quote Link to comment Share on other sites More sharing options...
TLN Posted October 14, 2016 Report Share Posted October 14, 2016 On 9/14/2016 at 3:11 PM, Tanglefoot said: F2 Mass: 13% lighter than Kessler (2862g vs 3286 g) F2 Bending stiffness: 7.3% stiffer than Kessler F2 Torsional stiffness: 24% softer than Kessler F2 Bending frequency: 8.8% higher than Kessler (9.8 Hz vs 9.0 Hz) F2 Bending damping: 33% faster than Kessler (4 s vs 6 s) Just curios, isnt Cross a metal board? Carbon f2 have to metal (WC does). I'm not sure about cross though. On 9/15/2016 at 0:41 PM, Tanglefoot said: BlueB, thanks for your feedback. Everything I have learned in life also points towards the Kessler as the grippier board, but I am not sure which of the measurements show this - if any. May be it's not Kessler, but F2 was made for different weight? While F2 position Eliminator as BX board, they're definately more user-friendly. ps. @BLOODTYPEZX10R soulds like something fun and interesting. Fx sounds extremely nice. Quote Link to comment Share on other sites More sharing options...
Tanglefoot Posted October 16, 2016 Author Report Share Posted October 16, 2016 On 10/13/2016 at 6:44 PM, BLOODTYPEZX10R said: I am Mark of Thirst snowboards, thank you Troy for the mention. I have researched ski and snowboard construction for years now and have not found one single company that has taken advantage of the main component...the core. I have been designing and building boards now for 37 years and have always built my cores differently. I create my cores using as few as 14 to more than 30 separate components. The board that Boardski mentions is the 7X. It has a asymmetrical core construction (for regular and Boardski rides goofy) and is a 179 all mountain design. The 7X has a carbon stack consumable above the edge and is hybrid in final assembly in that it is vacuum bagged but also pressed. As far as weight comparative to a board of the same length it has a waist that is 20.3 and shovel of 26.5, so it is fairly wide; hence the all mountain. I have since moved from the hybrid construction and carbon stack, it is too time consuming. I don't think that the comparison of my board to a Cadillac is quite fair. It is very responsive, easy to ride and extremely stable, not to mention fast. It loves very hard snow, rides great in powder and busts through chop, crud and slush. This board was my preference no matter what the conditions, but it is retired now and I have moved on to even greater designs and ideas to please my ever illusive customer. Thirst is on FB and you can find a link to my website there. UMUSTCARVE has some video from a few years ago on youtube you can check out. Hi Mark, First of all, I think "Cadillac ride" is only ever meant as a compliment on this forum. Secondly, it is great to see some alternative ideas being put into practice, and I would love to see a bit more technical detail than is currently on your website. Be sure to protect your trade secrets though... Meanwhile, back in the woods of Buskerud: I have performed some simplified analysis since my last post, and I think that if the aim is to replicate the Titanal layer, the following laminate would work: Two unidirectional layers of standard modulus carbon fibre at +45 / -45 degrees for the torsion, and a layer of 0/90 woven cloth for the bending. This is not the best way to make a lightweight board, but with the correct fibre weights, this laminate will match the torsional stiffness, bending stiffness and mass of the Titanal layer. This can be fine tuned with the aid of any freeware classical laminate analysis program. There has been some really good input on this thread, and I am more convinced than ever that an all-composite board can do the same job as a metal board. However, I am thinking the same as some of the other "posters" here; that the mass is really important, perhaps more so than damping, and that the effect of added mass is often mistaken for damping. This might explain the use of P-tex topsheets. Perhaps the cheapest way to the goal is to engineer a lightweight triaxial laminate with only unidirectional carbon fibres, and then add P-tex or simply a heavy rubber layer to create the desired mass. Mark - I am slightly unsure why you need such a technical core. The shape / thickness distribution is clearly important, but apart from that I though you only needed sufficient shear strength and shear stiffness, since the skins do most of the bending and torsional work? I am fully open to being enlightened on this matter. Quote Link to comment Share on other sites More sharing options...
Tanglefoot Posted October 16, 2016 Author Report Share Posted October 16, 2016 On 10/14/2016 at 10:50 PM, TLN said: Just curios, isnt Cross a metal board? Carbon f2 have to metal (WC does). I'm not sure about cross though. May be it's not Kessler, but F2 was made for different weight? While F2 position Eliminator as BX board, they're definately more user-friendly. ps. @BLOODTYPEZX10R soulds like something fun and interesting. Fx sounds extremely nice. Hi TLN, The reason for choosing these two boards for comparison is that they are very similar in terms of purpose, rider weight range, length, width, sidecut etc. They are both boardercross type boards, but crucially, the Kessler is a metal board and the F2 is a composite board, so this was my one chance to perform a back-to-back comparison. Unfortunately, the F2 is quite an odd construction in terms of lay-up, which makes it less relevant than if it had been optimised in a similar way to the Kessler. Still - I can only learn from it. Not all experiments lead to great breakthroughs; some seem to be limited to rather incremental gains of knowledge. At least we're having fun... Quote Link to comment Share on other sites More sharing options...
lowrider Posted October 16, 2016 Report Share Posted October 16, 2016 Not sure what you mean by engineer a lightweight triaxial laminate with only unidirectional carbon fibres since a triaxial would by definition have 3 axis. Would your requirement be to have a triaxial carbon fibre laminate ? Quote Link to comment Share on other sites More sharing options...
Beckmann AG Posted October 16, 2016 Report Share Posted October 16, 2016 ^He might mean a triaxial laminate composed of three independent layers, rather than a single layer of one triaxial weave fabric? If such a thing exists? Most of my experience is with 'hoop', 'linear' and 'twill', so... Quote Link to comment Share on other sites More sharing options...
BlueB Posted October 17, 2016 Report Share Posted October 17, 2016 I'm not aware of a triaxial weave either... But, one can easily get 45/45 and 90/0 biaxial and combine them in quadraxial. That should do. Quote Link to comment Share on other sites More sharing options...
lowrider Posted October 17, 2016 Report Share Posted October 17, 2016 Would be interesting to work with without the weave holding it together. Still holding out faint hope for my tensioned stringers but unable to work on it right now. Quote Link to comment Share on other sites More sharing options...
Beckmann AG Posted October 17, 2016 Report Share Posted October 17, 2016 (edited) The K2 KVC boasted some sort of triaxiality way back when. Granted, that was glass, not carbon. Don't recall the specifics, but seem to recall using a torsion box/fiberglass sock construction. The implication being that it was one weave, but that might have been the marketing weasels at the helm. They were on the vanguard of the new wave of torsional rigidity. (The skis, not the weasels). https://offerupnow.com/item/detail/172119286/vintage-k2-kvc-tri-axial-slalom-skis Edited October 18, 2016 by Beckmann AG 1 Quote Link to comment Share on other sites More sharing options...
BlueB Posted October 17, 2016 Report Share Posted October 17, 2016 1 hour ago, lowrider said: Would be interesting to work with without the weave holding it together. You don't need weave to hold it together. The stitches hold the 90 and 0 layers together (or 45s) in non-woven laminates. Once the matrix is cured, the straight overlays are stronger then woven and more resin economic. Quote Link to comment Share on other sites More sharing options...
west carven Posted October 17, 2016 Report Share Posted October 17, 2016 howdy this is the future... Quote Link to comment Share on other sites More sharing options...
TLN Posted October 17, 2016 Report Share Posted October 17, 2016 19 hours ago, Tanglefoot said: Hi TLN, The reason for choosing these two boards for comparison is that they are very similar in terms of purpose, rider weight range, length, width, sidecut etc. They are both boardercross type boards, but crucially, the Kessler is a metal board and the F2 is a composite board, so this was my one chance to perform a back-to-back comparison. Unfortunately, the F2 is quite an odd construction in terms of lay-up, which makes it less relevant than if it had been optimised in a similar way to the Kessler. I have similar F2, but Worldcup edition. That's metal board, and would be fair to compare to Kessler. I agree that top clear layer affects the performance. But IMHO, metal adds so much to the board, so you should only compare metal-to-metal boards. Carbon vs glass is fine to me. Quote Link to comment Share on other sites More sharing options...
Tanglefoot Posted October 17, 2016 Author Report Share Posted October 17, 2016 18 hours ago, lowrider said: Not sure what you mean by engineer a lightweight triaxial laminate with only unidirectional carbon fibres since a triaxial would by definition have 3 axis. Would your requirement be to have a triaxial carbon fibre laminate ? Sorry - I wasn't being entirely clear... If the aim is to end up with fibres in three directions, there are several ways to combine materials for similar results. The way I had in mind was to use three plies of unidirectional material and lay them up in three different orientations. So unidirectional plies, but triaxial laminate. You can also buy ready-stitched triaxial mats, but you then have fewer to choose from in the marketplace, and less opportunity for fine tuning your laminate. To keep the weight acceptable but keep the torsional stiffness up, I think the diagonal fibres need to be carbon. Woven fabric is difficult to use for these plies, since most fabrics are woven at 0/90, and the rolls are not wide enough to lay the plies at 45 degrees without lap joints. This is probably why manufacturers such as F2 use carbon weave at 0/90 even though this is not a very efficient use of the material. Structurally, three axes should be enough, but I also mentioned the 0/90 weave as a way of making the laminate match the Titanal. The diagonal layers come in addition to the weave, and could then be angled more or less to fine tune the flex and torsional stiffness, or to fit in with the builder's stock materials. Just needs a little analysis... Quote Link to comment Share on other sites More sharing options...
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