Spring Loaded Camming Devices (SLCDs) come under the heading of active protection and are one of the most versatile weapons in a climber?s arsenal. In this article you will find a brief outline of the different types available and what to look for when you begin building a cam rack. There are a number of articles on this site which take a more in-depth look at putting together your first trad rack and placing protection.
The Russian, Vitaly Abalakov, invented the Abalakov Cam way back in the 1930?s. These were based on the mathematical logarithmic spiral shape, in order to maintain a constant angle between the cam and the rock at each contact point. It wasn?t until 1974 that Ray Jardine invented the first SLCDs and named them Friends. These literally changed the course of climbing history. For the first time, both parallel and flared cracks could be protected.
Today we have a huge choice of cams, and they have come a long way, but they are all still based on the original Friend from Jardine which is still in production by Wild Country.
The first thing a new climber will notice is that camming devices are not cheap, and cost significantly more than any passive protection. When you?re first starting out there really is no immediate need to own any cams at all, and it is well worth learning how to place passive protection well before you invest in your first cams. As with passive protection a little research into the areas that you intend to climb will help you decide what type and sizes will provide the most benefit. Check online and in guide books for suggested racks, or even better, give us a call or an email and we can help you out.
These are the closest cams to the original design by Ray Jardine and most, if not all, still use the 13.75 degree angle that Ray calculated back in 1978. Single axle cams are lighter than double axles, but have a smaller range. These tend to be a little cheaper than double axles, but you will need more of them to make up a full set.
Black Diamond was first to introduce the double axle design with their Camalots, but once the patent expired other brands quickly brought their?own versions out. A double axle design means each cam has a bigger range, and this means that in general you are more likely to place the right cam first go. They are a fair bit heavier than single axle units, but?when you compare a full set of each there may be little difference in weight. These are generally the best cams to go for when you?re starting out.
These have a single, flexible stem that will adapt to the angle of pull, working well in horizontal and vertical placements. They are usually made up of a flexible cable that is either enclosed or supported by a plastic frame or tube. The latest offering from Black Diamond, the X4, uses aluminium armour to protect the cable. One small thing to bear in mind with a single stem is that the trigger nearly always requires two fingers to operate it.
Double stem or U stem, this design is used by DMM on their 4CUs and by Metolius on their Supercams. This system can give the stem more rigidity that can help with placements. They also tend to be lighter than a single stem equivalent. One real advantage is that the trigger can be operated with just one finger, so it can be placed when you are at a total stretch. Double stem cams are good value for money when you?re on a budget, and work well to compliment a double axle rack.
This is the sideways diameter of the unit, and in general is more important for larger sized cams. A cam that is too narrow will be unstable, whilst a cam that is too broad will not fit into shallow cracks and such. This isn?t something to worry too much about as manufacturers have made most of the decisions for you, but it is worth comparing different head widths between types and brands, especially if you know you?ll be placing them in narrow pockets or pin scars.
Cam stops?not only prevent the cam lobes from inverting, they can also hold a load in passive or umbrella mode. Up until recently, only double axle cams could do this, but now that most cams are forged rather than cut, most good single axle cams now have cam stops. While?it is never a good idea to simply?hang a cam passively, a cam stop can help a tipped out unit hold a fall, and if nothing else will help prevent the trigger mechanism from snapping when dragged through a crack.
Number of Cams (Lobes)
The number of cams on a device, also known as lobes, varies. Most use four as this gives the most stability and surface contact area, but there are also a number of options available with only three. The benefit of having fewer cam lobes is that the unit will fit into smaller spaces, but this design will have considerably less holding power than a normal four lobe unit.
All cams come with a small length of sown tape attached to the end of the stem. Some of these, like DMM Dragons, have an extendable sling which can be shortened or lengthened, and have the advantage that you may not need to attach an extender to it.
These are units that have two lobes of one size and two of another size. They are seldom seen in the UK, but are the only cam type that will deal with small pin scars and off-width cracks. If you?re not convinced, just take a moment to think of the last perfectly parallel crack you encountered. These are a worthwhile addition to any rack, and essential if you?re planning on climbing in the US.
Just like the larger ones, but from small to miniscule.
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