What is ski camber and rocker shape?
Even experienced skiers are confused by the evolving shape of skis, both seen from above (parabolic shape, width) as well as sideways. This SwissCorps article will help clarify what this is all about and what kind of equipment to bring depending on the proposed deployment.
We are adapting a great article from Wagner Custom Ski below. They are a great company and sometimes we don’t mind giving some extra spotlight to a worthy competitor and colleague.
For many years, most skis had one thing in common: ski camber. But what is camber, and how does it compare to rocker or early rise? Here, we take a closer look at ski rocker and ski camber and how these elements play a role once you hit the mountain.
To understand rocker and camber, it’s best to picture a ski on a flat, hard surface with the base side down. Traditional skis make contact with the ground surface in the tip and tail sections while the center of the ski is arched upwards. The two contact points often correlate to the widest parts of the shovel tip and tail. The section between these two points is essentially the ski’s effective edge. A ski’s effective edge is the section of ski that is used to make a turn, it is the length of the edge in contact with the snow when the ski is carving through a turn. As a point of reference, traditional race skis have significant camber, which helps ski racers track well on hard snow and initiate fast turns.
Ski camber reflects what you are picturing for a traditional ski, as seen in the figure above. With this ski shape, you have a longer effective edge. This translates to a more stable and controlled ride when skiing. Why? When you weight the ski, and initiate a turn, the forces you use distribute along the entire effective edge of the ski. In effect, much of the edge pressure applied to the snow is transferred out to the shovel and tail. This provides better stability, better edge grip, and precision on hard or icy surfaces. When you press the tip into the snow to help the ski “draw” into the turn, the effect is accelerated in a cambered ski, especially in moguls, where the shape of the camber helps maintain contact with the downhill face of each bump. Taken together, the longer effective edge holds a cleaner carved arc and offers a snappy transition into your next turn.
Ski Camber Pros:
- Ability to carve turns
- Precision when carving
- Stability throughout a turn
- Good edge hold and/or grip
- Quicker edge engagement when beginning a turn with forward pressure
- Better traction at high speeds on hard and groomed snow
- Good traction when skinning uphill (ski touring)
Ski Camber Cons:
- The effective edge seeks a firm surface (at the bottom of the snowpack), which translates to challenging powder skiing unless you can carve consistently in variable snow.
- Skis require precise technique in bumps and tight trees
Now picture a ski laid flat on the same surface. This time, the shape looks more like a water ski. The middle of the ski touches the surface and both ends arc upward, away from the snow. This shape, as seen in the firgure above, is what the ski industry refers to as reverse camber. In the 1970s, a few skis were built this way so as to concentrate the skier’s weight in the center of the ski for easy steering — they were sold to ski schools for use by first-day beginners. The first high-performance reverse camber skis, and possibly the most famous, were the Volant Spatula and K2 Pontoon. While these very wide skis had their time to shine, they are generally not recommended unless you are skiing perfect conditions (i.e. bottomless powder) all the time.
Reverse Camber Pros:
- Great flotation for deep powder conditions
- Perfect for helicopter skiing and snowcat skiing in perfect, bottomless conditions
Reverse Camber Cons:
- There is essentially zero effective edge which means carving a turn is very difficult if not impossible
- Feels like you are skiing on roller blades (side note: we have nothing against roller blades)
- Bad for traversing
Rocker, also referred to as early rise, is the happy medium between a full cambered ski and a reverse camber ski. Picturing the same ski on a flat surface, rocker is when the center of the ski has mild camber, but the rise, or upturn, of the ski begins behind the ski’s widest point (closer to the bindings). Similarly, rocker can be built into the tail of the ski.
The designer may give the ski symmetrical rocker (similar at the tip and tail), or can build in more rocker at the tip, or more at the tail. The more rocker, the shorter the effective edge becomes. This shorter effective edge correlates to a longer “rise,” the portion of the ski that doesn’t make contact with the snow.
Skis with a cambered center and tip rocker are a really good balance for many skiers, and have been very popular the past few seasons. It’s important to note that a little tip rocker can go a long way.
Tip Rocker Pros:
- Improved float in soft or variable snow (sun and wind crust, choppy snow, etc.)
- Easier turn initiation
- Better ability to stay in a centered and balanced stance which helps you plow through snow
- Helps a longer ski maneuver like a shorter ski
- Will save your legs in deeper snow
- Makes ski touring (skinning uphill) easier and more controllable
Tip Rocker Cons:
- The tip of the ski is prone to vibrations as you ski
- Skis don’t track as well on groomers and hardpack
In contrast to tip rocker, tail rocker is denoted by the tail section of the ski rising off the ground closer to the binding. This also reduces the effective edge, and increases the length of the tail that’s not making contact with the snow. This feature makes the skis feel softer.
Tail Rocker Pros:
- Good for surfy skiing
- Allows for easy pivoting
- Easier turn release in soft or deep snow
Tail Rocker Cons:
- Reduced tracking stability in long turns
- Less backbone and energy when turning
- Loss of stability and edge grip on hard snow
What does this all mean when evaluating or purchasing skis? In 99% of ski designs, camber is a good thing. It creates more versatility, with better edge control and stability, when you need it most. Camber helps especially well when skiing at high speeds, traversing across slopes, and skiing on firm or icy slopes. Having an effective edge is good: It helps you control your turn and gives you power. Camber combined with tip rocker generally makes a more versatile ski. These two features combined allow a skier to stay balanced, and lets the ski do more of the work when plowing through soft, variable and deep snow.
While ski camber and rocker affect the way a ski performs in various conditions, it is important to note that other factors affect the ski as well, including ski geometry (length, width, sidecut radius), stiffness, flex pattern, and materials. As a rule of thumb, camber is a good for versatility. Skis with camber and some tip rocker work well for all-mountain resort skiing. Skis with tail rocker are generally best for soft and deeper snow conditions