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C.A.M.P. Radion Ice Screws: Filling the Frozen Niche
Posted on: April 1, 2010
Lengths: 12, 17 and 22 centimeters
Weight: 155, 177, 199 grams
In early December, below Jeff's Slide in Smugglers' Notch, I racked up with my usual mix of ice pro and something new, C.A.M.P. Radion ice screws. I romped up the ice, found a fine screw placement and pulled a Radion from my harness. It bit into the soft ice and cranked quickly. Yes! And then: partway in, the crank arm caught on the rippled ice. You son of a...!
Two months later, I was building an ice anchor in the Notch as the mercury hovered around zero degrees Fahrenheit. One screw went in three turns and pop! Dinner plate. The next two screws did the same. But when I pulled out the Radion, it caught and sank deeper with less damage to the ice.
I tested the Radion for four months this winter on steep ice, meandering gullies and snow mountaineering slogs. In some regards, the Radion design is without equal. But in other respects—or the wrong conditions—the Radion is exasperating.
First, the good stuff.
I wanted to try the Radions ever since I learned of their unique threads. The basic structure of an ice screw is a metal tube with a triangular ribbon of metal wrapped around it. The leading edge of the thread (the side going into the ice) rises diagonally from the tube to a point and then straight back down to the tube. But on the Radion, it's opposite: the thread rises perpendicularly to the shaft and then diagonally back down. This means that the Radion enters ice with a flat thread surface. Counter-intuitive, right? But in brittle ice, this design distributes pressure over a larger surface area than normal screws, reducing the chance of fracturing ice.
The Radion is also unique in that it features both a floating hanger and a separate crank arm. Unlike other screws, this hanger does not rotate with the rest of the screw body. With the hanger below the crank arm, the designers had to find a clipping point that would not interfere with the spinning of the crank arm. Their solution was to attach a four-inch Dyneema sling to the hanger. This design allows a frightened leader to clip the rope straight to a Radion that is only partially placed; then the leader can finish cranking in the screw with some degree of protection.
The teeth, milled from three different angles, are awesome in cold ice. Combine those incisors with a long, solid-metal crank arm that leverages each turn, and you have a screw that zips into smooth ice incredibly fast.
At first, Radions seem heavy. A 17-centimeter Radion weighs 32 grams more than a 16-centimeter Black Diamond Express but 2 grams less than a 16-centimeter Grivel 360. However, because of the Dyneema sling, the extra weight of the Radion includes the better part of a quickdraw. This means that a Radion plus carabiner is equivalent to or lighter than a 16-centimeter Express, plus quickdraw.
However, all these features come at some expense. That first day, on Jeff's Slide, I discovered the first of three major drawbacks. The Radion's long crank arm gets in the way when sinking screws into heavily featured ice or between bulges. And its low profile makes it difficult to punch through debris, even when aided by hand or hammer.
Second, the free-floating hanger makes clipping awkward. The hanging Dyneema presents the user with two options: either leave a carabiner or quickdraw in the Dyneema at all times, or clip into the Dyneema on lead. One of my partners chose to clip in on lead and only had difficulties in windy conditions. Personally, I found this process awkward with frozen gloves. I frequently found myself catching a 'biner nose in the small Dyneema dogbone. Leaving a 'biner or quickdraw in the Dyneema full-time was an okay solution, but I resented having to determine which runner I would use before I left the ground.
My final gripe is that I found no convenient way to rack the Radion. Hanging a screw from the top of the Dyneema was a waste of a 'biner, and hanging one from the bottom of the Dyneema left the screw dangling just above my knee. Racking onto an ice clipper was okay, but it did not sit well on top of other screws, often sticking out at strange angles. My solution was to rack one per ice clipper at the very bottom with other brands of screws on top, or carry them on my shoulder straps in a Petzl Ice Flute.
Because of these drawbacks and its high price, I would categorize the Radion as a go-to niche screw. Though Radions will never become the backbone of my rack, I also will never leave the ground without a few on an extra cold day.
Pros: Sharp teeth bite well in cold ice; solid, low-profile arm offers great crank leverage; unique thread design fractures less ice; floating hanger allows leader to clip into a partially placed screw.
Cons: Long crank arm gets caught up on textured ice; awkward racking; expensive.
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