It appears we may have an ultralight climbing helmet war brewing for the Spring 2013 climbing season. Black Diamond initially claimed to hold the lightest, most breathable helmet title with the new Vapor, until last week Petzl announced the release of the even lighter, full-foam Sirocco climbing helmet.
The new Petzl Sirocco climbing helmet weighs just 165 grams, compared to 186 grams for the Vapor. The Sirocco is 50% lighter than the current Petzl Elios helmet (300-330 grams) or the Black Diamond Half Dome helmet (310-340 grams).
A typical climbing helmet is generally constructed out of some form of expanded polystyrene (EPS) foam, better known as Styrofoam, with some sort of Kevlar reinforcements. In order to create a helmet made entirely from foam, Petzl instead turned to expanded polypropylene (EPP), as it is more durable, flexible, and less brittle than EPS foam.
EPP foam is created by combining polypropylene resin with magic dust, then applying heat, pressure, and CO2 in an autoclave or pressure vessel, where the material is formed into small plastic beads. These small, closed-cell foam beads are injected into a steam chest to create parts custom molded into complex shapes using steam heat and pressure.
Products molded from EPP foam are remarkably durable, lightweight, and completely recyclable. EPP has excellent energy absorption and high strength properties that can resist multiple impacts, perfect properties for a climbing helmet. The foam does not support microbial growth so will also help keep your helmet stink free in summer.
To help with ventilation, the Sirocco helmet features numerous openings that are evenly distributed across the sides and back of the helmet while still protecting the top and front of your head. The climbing helmet comes with a new magnetic buckle, which allows the chinstrap to be attached using one hand.
The Petzl Sirocco climbing helmet will be available in time for the Spring 2013 climbing season.