BlueB Posted October 17, 2011 Report Share Posted October 17, 2011 Tinkler had that configuration when he started converting Hangles to plate... It is a very wrong thing to do from mechanical/geometrical point of view. If the board and plate 0 torsional flex, that configuration wouldn't even work. However, I'd need to build/ride one, to really tell the difference. Quote Link to comment Share on other sites More sharing options...
Corey Posted October 17, 2011 Report Share Posted October 17, 2011 The mechanics of offset pivots confuse me too, but I don't think many people on this forum have the experience needed to say that JJA is wrong. ;) Quote Link to comment Share on other sites More sharing options...
b0ardski Posted October 17, 2011 Report Share Posted October 17, 2011 I have no experience with plates but am a fan of asymmetric flex (and pedaling). Asym plate mounting is certainly not new, but I'm thinking with the isolation type of plates, the 4 offset mounting axels would all have to be in sliding mounts to prevent any bindup between the plate & board? Quote Link to comment Share on other sites More sharing options...
kieran Posted October 17, 2011 Report Share Posted October 17, 2011 I have no experience with plates but am a fan of asymmetric flex (and pedaling).Asym plate mounting is certainly not new, but I'm thinking with the isolation type of plates, the 4 offset mounting axels would all have to be in sliding mounts to prevent any bindup between the plate & board? mmm, tricky. are any of them only a pivot, instead of a slider? Quote Link to comment Share on other sites More sharing options...
Jack M Posted October 17, 2011 Report Share Posted October 17, 2011 The asymmetric mounting points confuse me. His offset pivots look like they will affect the board flex in an odd way. Even if he has no actual axle, there is still a virtual axle created by the plate, and it runs diagonally across the board. Think about the plates we have seen thus far to date - if you place the axle under the toe of the front foot, the heel will be further away from the board when the board decambers. That is, the gap between plate and board will be larger under the heel than the toe as the board bends. If you were to place the axle under the heel of the front foot, (not that you would) the plate under the toe would probably collide with the board. Jasey Jay's plate connects to the board under the heel and toe. This will load the board diagonally when it decambers. The offset connection points will force the gap between the plate and board to be constant under the whole foot. This is confirmed by the enlarged photos posted by SunSurfer. I'm not sure what effect this will have as JJ obviously likes it and he would know better than me, but it certainly is curious. I'd love to know the intentions going on here. (I realize it's not quite exactly under the heel and toe, but it is still offset diagonally) Quote Link to comment Share on other sites More sharing options...
pokkis Posted October 17, 2011 Report Share Posted October 17, 2011 Distance between axles looks to be bout 3cm so height difference will be quite small. I mean atleast in this picture: Quote Link to comment Share on other sites More sharing options...
BobD Posted October 17, 2011 Report Share Posted October 17, 2011 My 2 cent theory. When we angulate in a turn we torque the board, whether we intend to or not. The plate would have to be very stiff to totally eliminate torquing. The off set plate mountings would also torque the board, but opposite (?) to the natural torquing from angulation. This might allow a less stiff plate to be used. Quote Link to comment Share on other sites More sharing options...
kieran Posted October 17, 2011 Report Share Posted October 17, 2011 maybe the cores of his boards are laid-up at an angle also, instead of wholly longitudinal. where's that magic 8-ball? Quote Link to comment Share on other sites More sharing options...
Jack M Posted October 17, 2011 Report Share Posted October 17, 2011 Actually, for a moment let's consider only the rear set of pivots, or hinges. As far as I know, the job of the rear mounts are only to hinge, while the front mounts need to hinge and slide. Are the rear hinges concentric? That is, do they share one axle? Or if not, are their axles on the same axis? Or are they offset? Without a photo of the bottom of the plate and hardware, it is unsure. But if they are offset, I think they would not be able to hinge. In this case the rear of the plate will be "locked" in place, relative to the board. You can imagine a simple door where the hinges are not concentric by a few centimeters. The door won't be able to open without seriously stressing something or ripping a hinge out of the wall. I'm just curious as to what's going on under there. Quote Link to comment Share on other sites More sharing options...
inkaholic Posted October 17, 2011 Report Share Posted October 17, 2011 4 corner axles, perpendicular to the board. Did not have it apart so I couldn't see the inner workings. Couldn't even tell for sure which end was sliding but appeared to be front. Plate was extremely stiff as was the board, ie; mid 90's custom race stock. Ink Quote Link to comment Share on other sites More sharing options...
BlueB Posted October 17, 2011 Report Share Posted October 17, 2011 Actually, for a moment let's consider only the rear set of pivots, or hinges. As far as I know, the job of the rear mounts are only to hinge, while the front mounts need to hinge and slide. Are the rear hinges concentric? That is, do they share one axle? Or if not, are their axles on the same axis? Or are they offset? Without a photo of the bottom of the plate and hardware, it is unsure. But if they are offset, I think they would not be able to hinge. In this case the rear of the plate will be "locked" in place, relative to the board. You can imagine a simple door where the hinges are not concentric by a few centimeters. The door won't be able to open without seriously stressing something or ripping a hinge out of the wall. I'm just curious as to what's going on under there. Now we are talking! Quote Link to comment Share on other sites More sharing options...
www.oldsnowboards.com Posted October 17, 2011 Report Share Posted October 17, 2011 Tinkler had that configuration when he started converting Hangles to plate... It is a very wrong thing to do from mechanical/geometrical point of view. If the board and plate 0 torsional flex, that configuration wouldn't even work. However, I'd need to build/ride one, to really tell the difference. Think back. I believe it would be more accurate to state that the Hangl plates systems ARE offset or staggered in their design. Mike builds to the racers requests. At that time Hangl was the one to have, boards were designed around them. Mike bridged the dual plate design with a single plate (as he has done for many years). It went to the Olympics again:) At some time in the future, I believe the amount of rotation and travel of the current plates systems will be recognised as less important. I believe the discussion about stagered pivot/sliders is valid yet given more importance that it warrants. Quote Link to comment Share on other sites More sharing options...
Ladia Posted October 17, 2011 Report Share Posted October 17, 2011 How this scheme works with your stand? Is the board on picture set up for regular? Quote Link to comment Share on other sites More sharing options...
Jack M Posted October 17, 2011 Report Share Posted October 17, 2011 At some time in the future, I believe the amount of rotation and travel of the current plates systems will be recognised as less important. It is a suspension system, travel is important. I think the fact that the Karl design is so successful is due in no small part to the fact that it has the most amount of travel of any system to date. I believe the discussion about stagered pivot/sliders is valid yet given more importance that it warrants. If in fact the mounts cannot hinge, I think that is important. Would be great to have some answers on this. Quote Link to comment Share on other sites More sharing options...
www.oldsnowboards.com Posted October 18, 2011 Report Share Posted October 18, 2011 It is a suspension system, travel is important. I think the fact that the Karl design is so successful is due in no small part to the fact that it has the most amount of travel of any system to date.If in fact the mounts cannot hinge, I think that is important. Would be great to have some answers on this. How much travel do you believe you need Jack? Travel distance required is easily attained in all systems I have seen. Typically there is more than enough. Many of the new builders of plates over estimate the potential travel distance. What degree of rotation do you estimate the "Hinge" requires? Again. A wheel needs an axle so it can rotate 360 degrees. A typical door maybe 180 degrees at the most. How much do you think the plate rotates? To be clear: By "Travel" I am referring to the distance the plate/board slides relative to the other. Not up/down flex of plate/board. Quote Link to comment Share on other sites More sharing options...
www.oldsnowboards.com Posted October 18, 2011 Report Share Posted October 18, 2011 How this scheme works with your stand? Is the board on picture set up for regular? Yes. The set up pictured is for a regular stance. The pattern and plate mount allows for the rider to set it up any way you like. Lots of options. Quote Link to comment Share on other sites More sharing options...
BobD Posted October 18, 2011 Report Share Posted October 18, 2011 Actually, for a moment let's consider only the rear set of pivots, or hinges. As far as I know, the job of the rear mounts are only to hinge, while the front mounts need to hinge and slide. Are the rear hinges concentric? That is, do they share one axle? Or if not, are their axles on the same axis? Or are they offset? Without a photo of the bottom of the plate and hardware, it is unsure. But if they are offset, I think they would not be able to hinge. In this case the rear of the plate will be "locked" in place, relative to the board. You can imagine a simple door where the hinges are not concentric by a few centimeters. The door won't be able to open without seriously stressing something or ripping a hinge out of the wall. I'm just curious as to what's going on under there. That's was kinda my point. A snowboard isn't a door. it will contort i.e torque. So is this intended contortion? Quote Link to comment Share on other sites More sharing options...
Jack M Posted October 18, 2011 Report Share Posted October 18, 2011 How much travel do you believe you need Jack? Travel distance required is easily attained in all systems I have seen. Typically there is more than enough. Many of the new builders of plates over estimate the potential travel distance. What degree of rotation do you estimate the "Hinge" requires? Again. A wheel needs an axle so it can rotate 360 degrees. A typical door maybe 180 degrees at the most. How much do you think the plate rotates? To be clear: By "Travel" I am referring to the distance the plate/board slides relative to the other. Not up/down flex of plate/board. The distance the front mounts slide and the degrees through which the front and rear mounts pivot are relatively small, but they have a large effect. When my Boiler plate is mounted on my board it is very close to the board when the board is relaxed. 1cm tops. In my living room I can bend the board with one hand and fit my other hand between the plate and the board with wiggle room to spare. That's a lot of travel. The small pivoting/sliding movements of the mounts are what allow that. I believe it is this action that has made the Karl style plate so successful. Quote Link to comment Share on other sites More sharing options...
SunSurfer Posted October 18, 2011 Report Share Posted October 18, 2011 This will probably only be of interest to people with a technical interest in decoupling plate design.At the sliding end of the plate, how much movement will occur as the snowboard reverse cambers / decambers in the deepest part of a carving turn? The geometric answer is the length of a chord, connecting the two ends of the arc that represent the plate attachment points on the board, subtracted from the distance separating the attachment points. The sagitta is the maximum distance between chord and arc. I was playing with my prototype decoupling plate mockup by decambering the board and was surprised to see how little slide movement appeared to be occurring. If I actually worked through the geometry rather than just making a lazy guess what would be the result. r = radius of decamber curve x = known arc length (attachment point distance) c (circumference) = 2*Pi*R a (arc angle) = x/c*360 L (chord length) = r*sine(a/2)*2 s (sagitta) = r - square root((r*r)-(L/2*L/2)) When the math is done, if the distance separating the attachments was 700mm, and the board decambered by a sagitta of approx. 15mm between those two points, the chord connecting the two attachment points arc is now approx 699mm long i.e just 1mm different! The decambered curve of the board at this point matches the edge of a circle with a 4 metre radius! Using the same math calculation however, a separation distance of 500mm, bent to the point of approx 159mm radius, produces a circle of circumference 1000mm, an arc angle of 180 degrees, a sagitta of 159mm, and a chord length of 318mm. The values are clearly consistent, just by looking at them. I had thought that the slide movement required would be an order of magnitude larger and had built that kind of allowance into my own plate design. This result is leading me to reconsider how I allow for the sliding movement! I've sat down and done the math and saved it as an attached, zipped, spreadsheet for anyone who wants to check the math or plug in their own figures. The math if anyone needs convincing about how small the sliding movement needs to be. The spreadsheet is attached to the original post from March 2010 which can be reached by clicking the blue arrow at the top of the quote. SunSurfer Quote Link to comment Share on other sites More sharing options...
~tb Posted October 18, 2011 Report Share Posted October 18, 2011 I just took my Donek 178, with this years prototype plate and did a small test. I placed a mark on the slider at the resting position. I placed the board between my couch and chair suspended by about 25% of the tip and tail. I sat on the board to let if flex into a turn The arc generated is noted to be far less then pictures taken while actually riding that board I put a mark on the slider in its displaced position I then used my calipers to measure the distance between the two marks Result = 4.76mm I would expect that in reality, on the hill, 10mm is not out of the question in "normal carving use" at 5-10mm, I too would be concerned about an offset axel design putting nasty loads on the inserts etc. Another thing to keep in mind about how small the rotation needs to be, as a board undulates across an uneven pitch, the board both flexes in an arc, as well as locally flexing through a bump. the localized flexing of the board can cause the flexed radius to be half of that of the rest of the board. My bet, Jasey-Jay knows EXACTLY what he is doing here. He is just throwing everyone a head fake by sending out photos in the fashion. Look at all the free press it has gotten him on this forum. Quote Link to comment Share on other sites More sharing options...
~tb Posted October 18, 2011 Report Share Posted October 18, 2011 More so then the pivot and hardware design, I am interested in the stats that were debate last year about the Apex/Donek/Bomber/Virus plate shoot out at SES. How tall is it off the board? and how much does it weigh? The video showing Jasey-Jay installing the hardware sure makes it look tall. Quote Link to comment Share on other sites More sharing options...
ursle Posted October 18, 2011 Report Share Posted October 18, 2011 Boy is this interesting, I'm assuming this is JJ's board-plate, set up for the correct(right) foot forward, what I see is the angle the attachment hardware is at, it's at 45 to the board, not 90 degrees, so with my eyes I see the rear edge to be immediate or more so, as soon as the rear edge is touched it grabs, and the front edge to be less so, it's moved further back on the board, asymmetrical if you will but with the way the plate bends the board, I like it. you can set the forward(lean) angles and "cant" angles of your boots to have "either" more front or rear edge, and with this innovation you can fine tune the characteristics of any board to be asymmetrical for either leading foot, talk about days on the hill setting up a board. JMHO,YMMV:cool: Quote Link to comment Share on other sites More sharing options...
Jack M Posted October 18, 2011 Report Share Posted October 18, 2011 My bet, Jasey-Jay knows EXACTLY what he is doing here. He is just throwing everyone a head fake by sending out photos in the fashion. Look at all the free press it has gotten him on this forum. Ha, that would be funny. :D But I dunno, the pic of the plate in action shows it bending quite a bit. Quote Link to comment Share on other sites More sharing options...
trailertrash Posted October 18, 2011 Report Share Posted October 18, 2011 Look at all the free press it has gotten him on this forum. Is it odd to anybody else he hasn't chimed in personally yet? Quote Link to comment Share on other sites More sharing options...
lowrider Posted October 18, 2011 Report Share Posted October 18, 2011 With two small kids and trying to launch his business i don't think lurking in this realm would be a very productive use of his time. As an almost empty nester i would advise that you play when your kids are young and they may take you snowboarding when your old. As far as trying to personally coach everyone who might be interested in plates forget it! Pay your money take your plate and have at it, if it doesn't suit you sell it on the net!!! You will never know if you never try! Quote Link to comment Share on other sites More sharing options...
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