Splitboard.com Forums

The World's first exclusive splitboard discussion forums

It is currently Fri Nov 28, 2014 11:25 am

All times are UTC - 8 hours [ DST ]

Post new topic Reply to topic  [ 1 post ] 
Author Message
 Post subject: Help me design a board!
PostPosted: Mon Nov 17, 2014 4:06 pm 
User avatar

Joined: Sat Dec 07, 2013 1:14 am
Posts: 3
Location: Aviemore, Scotland
Hi all,
So recently I got talking with a local ski builder who is making super "eco" skis here in Scotland. I was really impressed by his use of flax fibres, plant based epoxy and locally sourced timber and said if he ever thought about making a split I would be very interested. I mentioned that a lot of people are unhappy with the offerings of the bigger brands and how it would be awesome to have a backcountry specific design. He told me he was in the process of moving into a new workshop and was totally up for including a board in his new moulds, and asked what ideas I had on board design!
So after being a long time lurker and reading loads of threads I thought it would be a great opportunity to try and get some opinions on here, hopefully without causing any flame wars, and try and come up with an awesome board designed by splitters, for splitters!

I also hope this could be a way to collect all the information on how different aspects of design affect the ride in one place, so a good way to do this could be to go through a design I came up with, explaining how I understand each part affects the board, and let you all correct me/tell me what could be improved!

So on to the design:
*Primarily designed for the variable conditions found in Scotland and other less than perfect snow areas. While a pow specific board is nice in a quiver, I can ride most boards in perfect powder, the true test is a board that handles steep, icy, chopped up nastiness and can be adapted to the situation on hand!

*I will use my own height (1.78m/5'10), weight (66kg/145lb), foot size (UK 9.5/EU 44/Mondo 28.5) and stance (18,-6) for the design, so bear this in mind with measurements.

The Shape:

-Board length
A longer board offers more stability and more float in powder, a shorter board offers more manoeuvrability and less swing weight. Around 161 feels good to me.

-Board width
Narrower means quicker edge to edge transitions, but too narrow and boot out becomes a real hazard. While people often use waist width as the main measurement, actual width underfoot is more important. Aiming for no more than 15mm boot overhang with TLTs (giving me quite a wide waist with the long radius discussed below)

-Effective edge
Not sure on this one, some boards go longer (NS prospector) and others rather shorter (Solution). I assume longer edge = more grip, shorter edge = quicker turns without losing length and float? I went in between the two for the above design (although with reverse sidecut it works out very short, see below). What is the science and preference here?

A small amount of taper is desirable to cause the nose to float and to "loosen up" the end of turns. Also places a setback stance over the centre of the sidecut. Around 12mm.

-Sidecut radius
The big one! We all want longer radii for big stable turns at speed, increased edge hold and less catchy-ness. Furberg stepped up! But some say maybe too much? (I'm yet to try one). About 11m on a 161 seems like a good compromise between stability and manoeuvrability, bearing in mind that most days here end with riding out on low angle, hard packed snow

-Sidecut profile
While the very informative videos from Donek make perfect sense on piste, how does this apply in the BC? Until recently it seemed elliptical radii was good - smooth initiation and release at speed but more responsive when the board was flexed for small radius turns. But the Prospector has the exact opposite and everyone that's ridden one has no complaints! Do we actually notice multiple radii in soft snow? Especially with the longer radius mentioned above?
Then the next step is reverse sidecut ala furberg. What is the difference between long "effective edge"/reverse sidecut and shorter edge/long nose? Surely the effective edge actually ends at the apex of the reversed sidecut making them effectively the same, perhaps with a less abrupt transition on the reverse sidecut? Is it that the reverse sidecut is still over the early rise part of the camber profile, rather than the more inclined nose? Despite my lack of understanding I like the concept so drew a small amount of RS into the design just for the fun of it!

-Tip/Tail/Waist width
Always popping up on specs sheets, they seem irrelevant and only a product of the above considerations. Although obviously more surface area = more float and therefore using "blunted" tips increases the surface area while keeping length the same.

A small amount of setback is good to prevent nosedives, but by using a rockered profile it doesn't need to be as much as in a traditional cambered board. Around 30mm.

Camber between the feet with early rise nose and tail has kind of become the established profile, but after riding an Icelantic Gemini I really like the RC profile - Playful and manoeuvrable at low speed but still stable and poppy. Kind of swaying toward the camber/early rise design though for the better uphill performance, but its a tough decision. Flat to rocker is out as it feels a bit lifeless to me while not offering any obvious advantages (although still preferable to trad camber IMO - too hooky)
The question is how much camber? around 5mm? maybe even less?

I would like a board that is quite stiff at the tip, I tend to ride from my front foot a lot - think Xavier de la Rue rather than Tom Burt - so its nice to be able to apply some weight without sinking the nose. Tail should also be quite stiff but poppy.
Between the feet I would personally like not too stiff. I'm pretty light weight and struggle to bend stiffer boards into tighter radii turns. Scotland is full of steep, tight couloirs so this is an important point for me. However I'm still looking for stability on open faces at speed so a compromise will have to be made (the stiff tip and tail should help, usually to get a board I can flex well I get stuck with something with floppy, jibby ends!)

I can see this being the hardest part of the board to get right and if anyone can help with starting points for core thickness that would be fantastic!

Torsional stiffness - how stiff is too stiff?

Although we haven't talked about it properly yet, I think the construction will be recycled P-tex base, flax fiber (replacing traditional glass), softwood core/hardwood under inserts/hardwood sidewalls (unsure on species), rubber foil dampening, another layer of flax and carbon stringers (after some discussion about carbon, we think the added performance and longevity of the board outweighs the environmental impact, and although Eco is the concept, performance cannot be compromised - we're not exactly going to stop using plastic boots or climbing rope any time soon!) and then maybe a thin wood top sheet. All held together with Entropy plant resins.

So if anyone managed to get to the end of all that I would love to hear your thoughts! I'm still quite a new splitter and I know there are plenty of people on here with far more experience than me. I'm completely open to all criticism and I realise I am probably slightly out of my depth, but its not every day you get to help design a board and I had to jump at the opportunity!


Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC - 8 hours [ DST ]

Who is online

Users browsing this forum: Exabot [Bot] and 9 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  

Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group