This story originally appeared in the July 2015 issue of our print edition.
Climbing might be free, but the gear is definitely not. A longstanding goal for climbers has been to lengthen the lifespan of every piece of gear in order to save money and be environmentally responsible, and understanding a product’s structure is crucial to keeping it usable for years to come. A crashpad is one of the most expensive single purchases you can make, and with a mostly foam, non-metal composition—plus the constant abuse from being dragged, crammed, and thrown around—they’re susceptible to deteriorating after just a season of regular use. To avoid spending $350 every year, we worked with chemical engineer and polymer consultant Galen Peterson to outline the basics of crashpad construction, along with a few ideas on how to prolong your pad’s life.
Made of polyurethane, this type of foam is stiffer, denser, and excellent for providing structure and resiliency, meaning it doesn’t deform drastically under impact, it bounces back to its original state very quickly, and it maintains that shape over time. The construction of closed-cell foam consists of thousands of tiny air bubbles that are trapped in place by solid, thin, and bendable polyurethane walls. Because the air is completely surrounded by solid walls, closed-cell foam is less compromising under pressure because the air can’t escape as easily. The main goal of this type of foam is to spread impact out across the surface area. It takes more force to bend and flex this rigid material, and the closed structure also makes it more resilient to water, i.e., it repels water instead of absorbing it. The unique ratios of closed- to open-cell foam will give each pad its own hard or soft feel, and the ideal mix will come down to personal preference. Try as many as you can to determine what firmness level is a good fit for you.
Also comprised of polyurethane, open-cell foam starts as closed-cell and then goes through an extra process called reticulation, which is a heat treatment that “unlocks” the closed-off construction to create a more open net-like structure. Imagine closed-cell foam as a completed house with solid walls dividing each room. Now take away the walls but leave the frame of the house; that is open-cell foam. The net-like build compresses easily under very little pressure because the holes allow air to escape quickly. This open net also absorbs water and air, acting like a sponge.
Most pads utilize three layers of foam that serve different purposes but work together. The top layer is thin closed-cell foam; the second layer is thick open-cell; then a third layer of closed-cell is on the bottom. Since it’s stiffer, the closed-cell on top disperses the impact of a fall over its entire surface area. This prevents you from hitting the ground through the pad. With the pressure distributed across a large area, it squishes down the open-cell to cushion the force of the impact and slow the fall. Another layer of closed-cell foam on the bottom gives the whole pad structure and stands up to abrasion from the ground. This water-resistant layer also keeps the spongy middle from absorbing liquid.
Keep Your Pad Alive
- Brush dirt off and allow it to dry completely before storing.
- Fix holes in the outer cover as soon as possible to prevent water and dirt from reaching the sensitive foam.
- Never store while compressed; make sure the foam has room to fully expand, including not storing with heavy objects on top.
- Don’t store in the sun or in a hot car; the excessive heat and UV rays will break down the outer material and foam.
- All crashpads, especially taco-style and hingeless pads, should be stored open to reduce wear and tear on the foam that’s folded.
- Pick the pad up as much as possible instead of dragging it across the abrasive ground.
Galen Peterson has a chemical engineering degree from Oregon State University and is a polymer consultant for the outdoor industry, as well as a sales rep for Kinetik Climbing.