In 1992 Grivel refined Greg Lowe's idea of a rigid rail underfoot – expressed in Lowe Footfang crampons, which were very advanced for their time (1972) – by hot-forging the frontpoints of the Rambo crampon. Forging allowed Grivel to remove steel where it wasn’t needed, reinforce it where it was, and create an aesthetically pleasing and utilitarian shape. Besides being far more rigid than stamped points, forging permitted an exaggerated 3-dimensional profile that prevented shearing through snow and rotten ice. These frontpoints, combined with vertical axis side rails formed a solid rail underfoot to improve penetration and reduce vibration. Rambo quickly became the reference point for all waterfall ice climbing crampons but also gained favor on steep, technical alpine routes despite a propensity to balling-up.
Over the years Rambo was refined in the Rambo Comp and eventually Rambo Evo. Both models were lighter than the originals and shaped asymmetrically to fit the curved soles of modern boots. The rearward facing tertiary points allowed one to pull in on steep terrain without the need for a heel spur.
The fourth evolution integrates the proven active anti-balling system, simplifies adjustment and modernizes point configuration. The anti-bott and Accordeon are built in to the system to prevent snow from building up underfoot. Three single bolts allow length adjustment, frontpoint replacement or heel spur removal respectively. Rambo 4 is a mono-point crampon that features a half-length support point to improve stability without affecting penetration. Aggressively featured tertiary points face the rear to provide maximum bite and versatility. Four points are oriented perpendicularly to the axis of the side rail points to increase security while descending. Rambo 4 is patented.