Forums DIY and Mods What's it going to weigh?
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  • #783359
    Scooby2
    600 Posts

    So inspired by Markus at Wildschnee’s 5lb 166 by 25.5 http://www.wildschnee.de/know-how-blog/manufaktur/2270 and Peter’s Milligram, I’m branching out, with a 167 by 26.5 for a 165lb rider sitting in the Preflex shed. I’m trying to hit 5lbs for the board w/o hardware. I was liking this weight till I added 4 ounces of inserts, now I’m just under 3lbs. Hmmm, Honeycomb?, channels? good enough?

    Trying tricks like no heavy wood in the middle, just flat grained maple inserts to back up the steel inserts, no inserts for heel lifters, just maple plugs for the screws. Maple under the feet and back on the heel side, more dense variety of poplar on the toeside.

    flat grained ipe plugs (from a flooring supply place) for water resistance and hardness for the tip and tail clips, probably shouldn’t even install one in the tail.

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    (Wasatch winter is going to go big, you heard it here first, well maybe not first but I support the idea 😉 )

    #783385
    buell
    534 Posts

    Love it. Those Ipe plugs are probably close to a pound alone. ; ) It is amazing how light you are projecting with such a thick core. It must just take so much less glass.

    I am getting a Milligram just to have a 5 pound board. Hope it rides well. I cannot wait to see more really light splits.

    #783386
    Taylor
    781 Posts

    Yeah, wood instead of glass and resin. Stoked to watch this one come together–and to see how low you can keep the weight. Keep us posted Scoob.

    @sun_rocket

    #783629
    Scooby2
    600 Posts

    Well 5 lbs is not happening, might have been unrealistic with a 26.5 cm wide board. It’s at 5 lbs 1 oz now with the base and edges pressed and excess resin sanded off the rails, without having the epoxy ground off the base.

    5.5-5.6 lbs is the new target! Still contemplating recessing in some honeycomb from the deck down. I have been weighing some paulownia scraps, they don’t weigh much and I’m not sure I’d save more than 3-4 ounces. There doesn’t seem to be much room in a split for honeycomb or foam with the hardware for the clips and the touring brackets.

    Next time, no inserts, just hard maple plugs for ski screws. I’ll probably seal the core with a thin epoxy coat before lamination next time also. I like the way the epoxy flows into and sometimes through the Paulownia wood core for shear strenght, but it no doubt contributes to more weight too.

    #783641
    HansGLudwig
    601 Posts

    Re: Honeycomb – Trimming fat out of tips and tails is all the rage to reduce weight in the ski world this season. Especially if there is considerable rocker. Check out Rossi’s Freeride lineup, all of Kästle’s lineups and Blizzard’s Carbon Flipcore tech.

    If you were OK with never adjusting stance, you’d know exactly where you could honeycomb and nowhere else. I.e. everywhere you see board.

    Here’s what Rossi did. . .

    Perhaps you could create an arc, from edge to edge, right where the hooks and pucks go.

    I see what you mean. It’s hard to save weight by trimming out an already light weight material.

    Be sure to bookmark Splitboard.com's Recent Activity page...
    http://splitboard.com/activity-2/

    #783659
    Scooby2
    600 Posts

    Those Rossis look pretty cool, I haven’t seen them in person. It would be pretty hard to drop honeycomb in the nose of this board now the way it is curved. I’d have to make a router base with the same curve on it. I was going to router in the space for honeycomb from the deck, leaving a few mm of wood above the base of the board for better impact strength.

    I’m going to taper the rails on all sides some more like a Fischer Hannibal ski and see how many ounces of sawdust I can make first. Turns out if I hit 5.75 (or even 6) pounds for a 167 by 26.5 this board will have a slightly heavier surface to weight ratio (using Wildsnow’s formula) than the Wildschnee board and will still have a negligible, but better surface to weight ratio than an Amplid Milligram or a La Sportiva Vapor Nano or Vapor Svelte, which is really cool! Those superlight touring skis might be lighter overall but at least we can keep bragging rights or at least hold our own as to float per gram (part of why one boards anyway).

    https://docs.google.com/spreadsheets/d/1Q67blAUbnD-XNLdnh-0hcPpOjmezMzzjmYlWNNbHaFI/edit?usp=sharing

    It might be that boards have a slightly better surface to weight ratio because the edge weight is smaller relative to the overall weight due to width.

    #783661
    HansGLudwig
    601 Posts

    Also contributing to surface area/weight of skis vs boards is the inside edges on skis is radially cut while inside edges of splitboards boards are straight.
    Imagine (or assuming) skis made from cuts of wood adjacent each other (like splitboards), you’d effectively be cutting an oval shaped hole in the middle.

    Back to shaving weight off your board – Have you considered thinning the board? i.e. the deck goes from 1/2″ thick under the bondings to 1/4″ thick at the tip and tail. A variant of this is thinning the center, a la G3 Scapegoat. (You alluded to this with “Channels?” in your OP)

    Also, you’re not planning to install metal rails on the inside edges, are you? If you must have them, try just putting them between the contact points or bindings, a la Chimera splits. I think they’ve moved on to some form of durable plastic for an inside edge.

    What do you think the damping on a board this thin and light will be like? I toured with a friend last season who was on some ultralight, carbon BD skis. They were too chattery in chop and skittery on crust. Until he was on those skis, I had never seen him fall. Just wondering.

    And thanks for sharing these builds @scooby2. You don’t have to, but I really enjoy seeing the product come to life.

    Be sure to bookmark Splitboard.com's Recent Activity page...
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    #783667
    Scooby2
    600 Posts

    Bases are on, inside edges are the thinner racing edges and cover about 50% of the board length, been doing that forever. Never as short as the Chimera’s boards though I probably should. Instead of thinning the core in the center or shaping the deck like a BD ski, I am going to make it rounder like the Fischer bc skis. I think they shed snow better and are easier to scrape.

    The signature of my boards is that they are nearly as thick (and stiff) from the nose through to the back foot. Overall they are waaay stiffer than any mfg board. They start off with a ton of rocker and then flex a limited amount to make fast round turns… It keeps them from overbending into really tight turn radii which makes a board have to drift more through turns and forces riders to keep the nose out of the snow further reducing surface area and speed out of turns.

    If I made them thin there’d be no point, I could just buy a board with a floppy nose that chattered all over the place. 😉 Also thin core boards need tons of fiberglass to handle the deep bends they make at the ends. Or in the future a combo of low modulus (stiffness) carbon coupled with innegra should completely replace the heavy plain e-fiberglass used today because it is really inexpensive.

    (oh the channels I was talking about would have been channels in the underside before laminating the base. I ‘ve taken most of my inspiration from the Fischer ski and XC ski websites. I was originally inspired by XC skis how they are an inch thick, crazy stiff and light in the center. Fischer had great pictures of how they cut vertical channels into their wood cores on their XC skis a long time ago.)

    Edit: I’m not really sure how the lack of weight will feel, I’ve been riding a 9.5 lb boards much like taylor’s since the 97/98 winter. I suspect they are better at destroying breakable crust, but a large part of that is a nose that doesn’t deflect–for anything. This year my board has similar flex but is down to just under 8 lbs much like the BD Carbon Megawatts but wider. We’ll see. But they don’t bend and flap at all like skis, especially at the tip. Also, I rarely encounter much crap snow as I have to cherry pick the best days to drop responsibilities and get out in the Wasatch, so snow’s pretty good when I get out.

    #783845
    Scooby2
    600 Posts

    Update, aspens are turning in the high country, one half of board has been profiled to have a curved deck and vacuum bagged with red gum veneer, spread tow carbon and a bit of innegra fabric between the feet, and through the tail for durability. Unsanded weight is 2 pounds 12 ounces. Looking good for a 5 1/2 pound board once sanded, spray finished and base ground! Makes me think 5lbs to 5 1/4 was doable but without veneer top. I do think they look better and protect the composite layer from UV and abuse.

    #785557
    Scooby2
    600 Posts

    Got the finish coat put on this 167 by 26.5 ripper, still need the base ground, so no more weight should go on from here, except all the hardware of course.

    I sanded pretty aggressively into the veneer to try and reduce its weight. The black areas or shady areas are where the carbon starts to show through.

    And the verdict is:

    5lbs, 13 oz. Not 5lbs flat by a pretty long shot. I’m real happy with it though after looking at the surface area/weight comparisions done with the math from Wildsnow-especially considering how stiff it is and that it has a top sheet and gloss coat. (It does bend though-made for 165lbs. and a light pack- not like the Chewbacca board I made for Taylor). By my math these boards, the Amplid Mg, Wildschnee’s 166, this board, are right on par with the top AT skis for surface area to weight ratio. Except we run with more surface area (and weight), have happier feet and have more fun in the best snow.

    I think I could drop 4-6 ounces by dropping the topsheet and gloss coat. I could drop 3 ounces by using ski screw into maple inserts for the bindings. I also have an extra ounce or two of excess resin in the deck because my vacuum line had melted partially shut and I lost a degree of vacuum pressure while laminating and my resin was too thick also for the type of fabric. (I press the base, shape the deck round, then vacuum the deck) So I think I could hit 5lbs 2-5oz-ish without the veneer and still have a thick stiffer board. I reckon that is as far as I could go without channelling the base or adding honeycomb, foam or balsa inserts.

    #785558
    Taylor
    781 Posts

    Awesome again! Another beauty. It’s interesting to read about the weight to surface area ratio, and how it is on par with AT skis. I wouldn’t have guessed that.

    I am waiting for one or two more storms before taking the preflex out this season. Still a few too many last-second obstacle unweights for me to want to risk a core shot.

    Not to nag, but can you, when you get the chance, post up a base-to-base shot of each ski to show the rocker profile on this one? And, can post a link to the surface area to weight calculator on Wildsnow? Sounds like a super useful tool…

    @sun_rocket

    #785583
    Scooby2
    600 Posts

    https://www.wildsnow.com/6270/ski-surface-to-weight-rati/

    https://www.wildsnow.com/9657/ski-weight-comparison-surface/

    Taylor, thanks! these are the basic posts about surface to weight ratios. The goal was not to find the actual cm per gram but to differentiate different skis. Check the google docs sheet that I put in above in my September 14 post. The formulas are there in the excell sheet, feel free to add to it. Your board is on there already I think. Lou basically cuts a fixed amount off of the tip, sets an arbitrary location for the narrow point of the ski and treats the sidecut as straight lines. I think it is pretty useful and fun to geek out on for those of us so inclined.

    That said, I don’t see how a 5-6 pound board could feel as good as a 9-9.5-10 pound board at 40mph and above. There is a stability that comes with weight that just can’t really be replaced.

    #785625
    Scooby2
    600 Posts

    Taylor, same constant curve as all of my boards so far. Same nose profile also so the rider doesn’t have to pay attention to it and keep adjusting their fore aft balance. This one has a much more sloping deck. Outside of the binding area and the nose, the deck is curved all the way across a la Fisher skis for weight reduction.

    #785708
    Taylor
    781 Posts

    Cool. Thanks for posting all of that up. I will add some decks to that spreadsheet soon. One of the more interesting metrics to me is surface area by itself. Adding weight is also interesting. Surface area fore of the front-most binding inserts would also be an interesting metric.

    Anyhow, beautiful board Scooby. It’s really fun to be able to watch your process here. Thanks for posting it up.

    @sun_rocket

    #788256
    Scooby2
    600 Posts

    Two tracks from the 167 by 26.4.
    From all observations, I think I got the flex just right for a 160lb rider, Wahoo!!

    #788379
    vapor
    350 Posts

    Awesome job again Scooby, love the work you do.

    #790970
    Scooby2
    600 Posts

    Warning: shaper’s pride moment

    Photo from today made by this 167 which shows it doing it’s job real well. Even in the lower angle part of these turns that the board was ridden fast, angulated a lot and was throwing the rider back and forth out of fast round turns without disturbing a lot of snow. All dense snow will do this to a degree, but this snow is pretty light and a board that doesn’t overflex spreads the rider’s weight out better and projects them into the next turn with more kick and more speed while disturbing less snow and wasting energy.

    I’m psyched that this board has had no base denting despite its light carbon layup and paulownia core and being subjected to plenty of logs and ice balls, wahoo! It’s seen a lot of miles and has had some epoxy repainted onto the rails from skinning scratches but that’s it. I’m already making two of these this summer for average weight riders 160-165 and will probably make a handful more if time allows so keep that in mind if you dig it. I’m going to use an inch of nylon topsheet on the rails to prevent having to repaint the gel coat scratches out on the rails..

    #791403
    JimmyC
    351 Posts

    Well deserved shaper’s pride. Awesome job!

    #791411
    Scooby2
    600 Posts

    Thanks JC! it’s been rewarding

    #791446
    Taylor
    781 Posts

    This…

    Even in the lower angle part of these turns that the board was ridden fast, angulated a lot and was throwing the rider back and forth out of fast round turns without disturbing a lot of snow. All dense snow will do this to a degree, but this snow is pretty light and a board that doesn’t overflex spreads the rider’s weight out better and projects them into the next turn with more kick and more speed while disturbing less snow and wasting energy.

    …is what for me most distinguishes the ride of a Preflex from other shaping concepts.

    More so than any other, the entire board passes through the same piece of snow with minimal sliding. In effect, it’s like powder railing — where the entire board, rather than the entire edge (on hard pack), passes through the same snow.

    It leaves deep, clean powder trenches. And it carries what at first is an alarming (and then extremely fun) amount of speed from turn to turn. And on a board designed for faster, longer radius turns, that’s truly exhilarating.

    I need to do a review of the Preflex. It’s been a year. I’ll work on that.

    @sun_rocket

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