When I was younger, I really wanted an off-road motorcycle. I had no means to own a motorcycle but could afford the next best thing; that being many copies of DirtBike magazine.
If I couldn’t ride it, I’d read it.
The late 70’s through the mid 80’s saw several important developments in motorcycle design, all of which were discussed ad nauseum in the magazines.
Water cooling delivered more usable power from a given engine size.
Improved suspension systems put that power to the ground, and kept it there longer.
Disc brakes improved handling and reduced lap times in competition.
It was an interesting time to be an enthusiast, even from the sidelines.
A few years later, mountain bikes saw a surge in suspension and brake development that very closely replicated the steps seen earlier in motorcycles. For example, the extremely successful Rockshox Judy used a damper in one fork leg, and a spring in the other; a concept introduced by CanAm/Bombardier a decade earlier.
Eventually, enhanced suspension and braking systems allowed riders to vastly expand the boundaries of their respective sports.
For snowboarding and skiing, water cooling gravity is pointless, and we can’t install disc brakes to our platforms. We can, however, examine the efficacy of our suspension systems.
Skis and snowboards are springs. Springs are simple energy storage devices. Springs without damping do not comprise an effective suspension system. In order to influence direction or store energy using spring tension, we need to maintain consistent contact with the bearing surface.
Skis and snowboards can affect, and be affected by their connection to our body mass– specifically our center of mass (COM). If we glide over a bump, and that bump lofts our center, the contact between working surface and bearing surface is disrupted as the trajectory of our center invariably ‘lifts’ our feet. If we glide through a rougher section of snow, and our COM bears too heavily upon our platform, contact will again be disrupted to our detriment.
The platform can hammer our center, and our center can similarly pound the platform.
Active and passive modes of suspension exist in alpine sport.
Active suspension is probably easier to grasp as a concept, as the casual observer can see the athlete using joint articulation and targeted muscle contraction to dissipate energy over time.
Passive suspension involves several principles that are less readily observed.
Effective use of active and passive suspension systems ensures that the platform responds as the athlete wants it to, rather than the platform dictating adaptive behavior of the athlete.
Next: Passive suspension systems.