YLE x RMU Pro Model Project

Forward from RMU

Welcome and thanks for following Wiley and RMU's pro model project. Our goal is to display some of the decisions that are really driving the design and function of a new product.  RMU has noticed there is a big gap towards the design process and communication of what a ski is truly designed for.

Like anything else, this ski is a new challenge for our team.  We expect that it will take several attempts for it to become a fully dialed production ski but we invite you to follow along with Wiley and our team as we prototype this product into a full production model.

 To kick things off we always start with one simple question for any product, What’s the purpose of this ski?

Designing A Ski 

Purpose:

 For Wiley, the purpose of this ski is generally an all mountain ski geared towards higher speeds in softer snow with the ability to perform in crud, chop, and still hold a turn at high speed.  We have been playing with a lot of dimensions but the sole focus of the design is based on a 25 m radius.   

The dimensions are the defining aspect of radius so here’s where we are starting.

There are many ways to change the radius with the dimensions like for example, shrinking or expanding the taper of the ski.  For the purpose of this ski Wiley wanted all mountain performance and float so we are starting with a longer tip and also adding a progressive radius to help with the all mountain performance.  The average of the progressive radius will be 25.

What it's NOT supposed to be:

(P: Spencer Harkins)

All to often a product gets misinterpreted,  "who would have thought our pow models don't hold an edge that well on groomers". To avoid this we are setting out with the expectation that this ski will simply never be good at the following....

Dimensions:

Initial dimensions are set at 122 underfoot.  There is a lot to consider here when we looked across the market studies for viability on the retail shelf, most skis over 120 really don't sell that well. The majority of the market tends to buy from 100 to 110.  With that said, this ski has a specific use and we hope will appeal to a niche customer that the general studies do not follow.   For RMU to exist we have to sell skis..... kinda makes sense so the question became again what are we designing a mass selling ski or a pro model with a specific use that only a niche will buy.

This is what we chose to start with:  143 143 122 138 138

Rocker Profile:

Tooling:

When we talk about toolng we are discussing the physical tools that are dedicated to making any one model of ski.  For example, the aluminum you can see in the photo above is the press cavity or molds you hear so much about.   When we are prototyping a ski we are testing lots of variables and changing the design constantly until we find a product that ultimately we will spend money for production level tooling on.  It’s important to understand this component of ski design as it drives the viability of the product long term.  My ski in one length will ultimately bare a cost of about $10k in just tooling to produce at Blizzard.  The more money spent on tooling the better the end product plain and simple.  

Tip Shape:

Working with cad and radius we want some sort of brand identifier for the ski  RMU has been doing a lot of biomimicry for the shapes and with that we all kinda liked the shape found below.

Biomimicry: the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems.

Yes, this ski tip shape came from the great white shark himself!

Contact Point:

When referring to the contact point in this case I am referring to where the the tip of the ski will engage when put on edge.  A ski with rocker traditionally engages its edge at the start of the rocker.   For this ski to help it “slash” in powder, we will be moving the edge contact point 2cm past the rocker point allowing the ski to get on edge or initiate a turn in powder with the rocker profile.

Cap vs Non Cap:

 Currently RMU has switched all production model caps.  We are running  a ¾ sidewall on every ski to reduce chipping.  As this ski is in the prototype phase the original skis will not feature a cap.   In the photo below you can see how the tooling must match bottom and top for a cap ski to exist.  This essentially means a cap ski cost twice as much to tool.

Material choices

When looking at a ski there are a million choices to be made.  For this first round of prototypes we have come up with a material schedule that we think will compliment the features we want from above and that will ultimately give Wiley the ski he is looking for.  As many skis as we have built over the years and the general idea of how this schedule will perform nothing insures the right combination of dimensions and materials.  It is a combination of knowledge of the materials and the skier feedback that makes a great product.

Cores:

Poplar...... we chose this wood as its light, snappy, and is high in modulus of elasticity.  This meaning it will have a good shelf life and longevity.  RMU readily had this wood available and recommended it over other woods for this reason.  I think its all to common people forget this side of the ski building process.   Could we source an exotic wood from the dark forests of Slovenia...sure is it economically feasible to ship it and build into a production level ski....not always.    With this the Matirx of core types there is a shift as there is an area of feasibility that reduces available choices if we want to actually be able to produce the product for consumers to buy at a dealer.

Tip Spacer:

We are starting with a 6 inch front tip spacer and 4 inch tail tip spacer.  This is a plastic that can take bonds better with fiberglass and handel the tip slap/shear values you get from jumping on a ski or landing on hard snow.

Core Flex: 

With the goal of the ski we wanted stiffer in the tail for stability with landing pop out of your turns and less wash out.   For the tip flex we wanted to have a smooth reaction to terrain variance.  The goal is to have a softer tip that reacts to the changing condition before the stiffer under foot portion of the ski is realized.

Another important thing to understand about flex is that the weight of the skier will change the way a core feels.   We are designing this ski for a skier who weighs 175 lbs, if you are over that it will feel softer if you are under that it will feel stiffer, If you weigh the same...well feel free to judge away!

Laminates:   

When looking at laminates we had a lot to consider.  Weight, flex, binding retention and well, 10 million other factors but those are the main three..   RMU stocks a 22oz triax meaning the glass has three weaves on a 45/45/90.  The main thing we are trying to achieve in this ski with laminates is being light weight and to have strong binding retention for the higher speeds.

In version one we are going to use a 19 oz triax binding pad and a 22 oz triax.  Our goal is to get the stiffness of the ski from the core.  Ironically you can add about 4 oz of epoxy for each layer of fiberglass. Obviously the thicker weights soak up more glass.   If this ski was going to be a designed like the Northshore 108, more so for charging big lines, we would switch the glass pattern to two sheets above and below the core.  The weight of that ski is more than we want for this pro model and I feel will also take away some of the deep snow performance being so stiff.

Sidewall:

There are a bunch of sidewall materials and theories on sidewall thickness.  Most major brands use UHMW sidewall or ABS.  RMU has gone to UHMW as it is more resistant to cracking.   For this ski we chose to run a 5/8 inch thickness.  Understandably this material is a utlra high molecular weight aka DENSE and not light.  For my use I am loading this ski on and off sled racks hitting rocks skiing through pillows and blasting lines in the resort.  For this use durability is being exchanged for weight.

Edges:

We choose a thick edge profile that has large teeth.  The main thing to understand on the selection here is is that the edge must match the thickness of the base.  There is also ability 200 profiles that feature different sizes and tooth patterns.  The profile we are using will have bigger spacing between teeth to allow the ski to flex but still have large enough teeth that the edge can take a good beating.

Base:

 The base of this ski in the prototype phase so we will feature no graphics as we will need to develop dies and special tooling that is not already in stock for the production model.  Our goal is to update the outdated RMU tip die.

 Wiley:

Just like edges, RMU presented me like 50 different options for base material.  Iso sport is the largest manufacture and is the base material you will find on most skis micro or macro level.  The US supplier is crown plastics and they produce a base that is 1.8 mil thick sintered and a real beast to core shot.  This base is not easy to tune, does come out of true and isn’t 100% flat as it is so thick.   As I look back to what we set out on the purpose of this is not a carving ski and so therefore we are choosing this base for a reason. 

Dampening Pattern:

We choose to run a full sheet of dampening underfoot to allow vibration to be absorbed through the entire ski.  We have also added a full pattern of VDS to the tip to also reduce chatter at high speeds.

Topsheet & Graphics

 For the graphic I wanted to distinguish between the final version and the prototypes we are building so we actually made to seperate versions.  Let us know your thoughts in the comments below...Naturally after we put in all the work on the final version graphic we ended up liking the prototype graphic quite a bit.

For this ski, we used what is called a PBT material.  It is probably most famously known from all the never summer products.  PBT is an awesome material for skis that do not have a half cap as it has one of the highest adhesion rates in the topsheet market.   This will help reduce chipping on the prototypes.  Once we settle on a final design, my goal is to switch to a lighter material from iso sport something in the range of .03mm instead of .05mm.  This will save a considerable amount of weight across both pairs.

Pressing The Ski:

Believe it or not this was actually the first ski I have pressed myself, and also kinda cool that it was number 1 in the series.  We used a 40 minute epoxy that under heat cured in about 20 minutes at 180 degrees.   The Epoxy we used is from entropy resins and believe it or not comes from tree sap with Low voc’s.  As this ski is pressed in what is called "open mold" some of the challenges are sidewall and graphic shift within the press.   Once we have final tooling we will be able to eliminate these issues.   

Here is my fresh, out of the press, ski.  Bill looks pretty stoked!

Finishing the Ski:

I am adding in a couple thoughts I had about the actual finish of the ski or everything to consider from after pressing.

Sidewall Angle:

I chose to go with a steeper angle for impact on rocks.  A more shallow angle allows for reduction in chipping but has less available material to absorb blows to the core.

Tune:

• Tip bevel with suttle detune in tip and tail sharp underfoot.
• 1 degree base bevel and 1.5 sidewall.
• Stone Grind

Wax:

The base we mentioned above on this ski features a 5% graphite content.  This means the ski base will be porous and need more wax more often.  

Testing process from here:   

Over the next few weeks I will be out skiing the ski and looking at all the variables mentioned above. I Imagine we will see tweaks to the turn radius and final dimensions as well as the laminate schedule.  Currently the ski is coming in just about 1450 grams and my goal is to drive this down below 1400.   More to come and thanks for following the project.

 Willey Miller