4 ms·

Expanding flakes (ones that will move when you pull outward on them) are not good placements for active gear. As the cam pushes outward on a fall the flake migh

Expanding flakes (ones that will move when you pull outward on them) are not good placements for active gear. As the cam pushes outward on a fall the flake might expand and the the cam might pull out because it is past it's usable range. Hammering pitons in a flake like this will do it too. As you hammer a piton higher up the flake it loosens the lower piton because it expands the flake from above to the point that the lower piton might fall out.

jfager 16y ago
Thanks. I do understand the mechanics, but the article seemed to imply that there are some flakes that people do use traditional cams to climb. I was more curious in how the line between safe and unsafe gets drawn than the theory behind why horizontal forces on flakes are dangerous. In other words: you pull on flake, and it moves - obviously, horizontal force is unsafe. But: how do you then decide a vertical force on the same flake is safe? Is it just feeling and experience, or are there actual rules people generally follow?
- aplusbi 16y ago
  Well from what I know this "anti-cam" device is the only rock protection that would not have a horizontal force component This guy is the first person to ever try it. All the other pro I can think of catches a fall by wedging into the crack, either by expanding or by taking advantage of a natural choke point.
- kscaldef 16y ago
  Well, you can't actually do an engineering analysis of a rock face, so you're never going to achieve that level of rigor. Placing protections and building anchors is a combination of experience and intuition; observation and analysis techniques; and a bit of actual physics around angles, direction of force, rope stretch, and force multipliers.
- weaksauce 16y ago
  There are guidelines that people follow but there is no hard and fast put this here like this and it will hold a fall from 75' up rules. It is a lot of feeling and intuition and most importantly redundancy!

jfager 16y ago

Thanks. I do understand the mechanics, but the article seemed to imply that there are some flakes that people do use traditional cams to climb. I was more curious in how the line between safe and unsafe gets drawn than the theory behind why horizontal forces on flakes are dangerous. In other words: you pull on flake, and it moves - obviously, horizontal force is unsafe. But: how do you then decide a vertical force on the same flake is safe? Is it just feeling and experience, or are there actual rules people generally follow?

aplusbi 16y ago
Well from what I know this "anti-cam" device is the only rock protection that would not have a horizontal force component This guy is the first person to ever try it. All the other pro I can think of catches a fall by wedging into the crack, either by expanding or by taking advantage of a natural choke point.
kscaldef 16y ago
Well, you can't actually do an engineering analysis of a rock face, so you're never going to achieve that level of rigor. Placing protections and building anchors is a combination of experience and intuition; observation and analysis techniques; and a bit of actual physics around angles, direction of force, rope stretch, and force multipliers.
weaksauce 16y ago
There are guidelines that people follow but there is no hard and fast put this here like this and it will hold a fall from 75' up rules. It is a lot of feeling and intuition and most importantly redundancy!