Ski Builders Forum

hi all,

i'm curious if there's any concensus in how the flex scale (1-10) that all board manufacturers use when describing the flex of their products translate to actuall numbers? (N/mm).

i'm using the ski calculator provided by junksupply.com which i think is a great tool. but, my practical experience in translating these numbers and comparing to "industry standards" is zero.

let's say i have a favourite board which that company says has a flex of 7 (10) and want to achieve the same flex in my next build.

my current layup is the following;

splitboard
158 cm
26cm waist
30.5 nose
28 tail

ptex base
vds rubber
22oz/618g triax glass ( 0=283g, +/-45=144g)
2x (50mm x 130g) UD carbon (one on each ski)
2.5 - 7.5 - 2.5 mm (~40% paulownia, ~60% poplar)
2x (50mm x 130g) UD carbon (one on each ski)
22oz/618g triax glass ( 0=283g, +/-45=144g)
0.6mm bamboo veneer
PU top coat

the ski calculator tool gives me;

core mass: 1132g
core stiffness: 219N/mm
triax glass + ABS sidewalls + steel edges mass: 1153g
triax glass + ABS sidewalls + steel edges stiffness: 391g
UD carbon stringers mass: 72g
UD carbon stringers stiffness: 100N/mm

So, I end up with a board that should weigh around 2757g and have a stiffness of 710N/mm (in theory), which according to the ski calculator is
at the upper end of it's "medium" stiffness scale.

Now, anyone knows how far away that would be from a 7/(10) on the traditional stiffness scale?

I assume its just marketing bullshit and the manufacturers scale the scale to their own vision of flex

i suppose you are right.

i guess i just want some reassurance that i won't end up with a board that is too soft.

i've been trying to find a good balance between weight and strength, but like i said, all i have are numbers and very little experience.

anyone got any input on how they'd perceive the flex of this layup?

For a splitboard my guess would be that your numbers are on the softer side of medium (the calculator does not account for the board being split, but splitting the board makes it significantly softer).

As for the flex scales used by different brands, those are not really a standardized indicator. Getting the right amount of flex really comes down to your own experience.

thanks for the insight chrismp. i might go up a mm in core thickness to account for the split.