Cam and Get’Em

Spring-loaded camming devices (SLCDs) have been saving climbers’ lives and calming jittery nerves for nearly three decades, bringing instant high-strength protection to all rock types and at all grades. The beauty of the SLCD is not only that it gives a broader size range than fixed passive protection (nuts), and that it works in a wide variety of placements where such passive protection won’t (parallel cracks, pods, flares), but that it fires in with minimal fuss, saving arm power easily lost fiddling with wires. SLCDs are also very forgiving pieces of protection, very rarely ripping even when badly placed, and generally, if it goes in, it’ll stay in.

The problem is that deciding which SLCDs to buy when building a rack, or replacing those original solid-stemmed ’70s Friends, can prove a dizzying and confusing affair, as the sheer range of SLCDs on the market makes the choice anything but simple. As with most things these days there is a mass of conflicting advice on what makes the ideal cam, with every manufacturer singing the praises of their own design. Another factor is the huge difference in cam prices, with budget models coming in at well under £20 and others retailing for £40, begging the question: how much better is a £40 cam over a bargain-basement cam?

The aim of this article is to make this choice simpler by giving a little more background to the decisions involved.

Stem designs

Single flexible stem
Introduced by Wild Country with their single steel-cabled flexi Friend, this design creates a stem that can adapt to the angle of pull, working even in horizontal or shallow placements. The single stem is flexible in all directions and generally returns to its original shape and orientation. One drawback is that when force must be applied to the trigger (such as when trying to unstick a unit), the cable can bend, making it harder to operate. This has been overcome on several models by enclosing or supporting the cable with a plastic frame or tube, creating a stem that is both rigid and flexible.

Flexible U-stems

This style of frame is best demonstrated by the now-defunct HB Quadcam, with a steel cable forming a U-shaped stem attached on either side of the cam head. This design gives an almost semi-rigid structure, aiding placements and protecting the trigger wires (which are held in line by the stem itself), while also allowing very low weight. The downside is that the cable can interfere with some placements and can become bent if loaded across the U-frame, where it is rigid.

Rigid stem

These days only Wild Country produce rigid-stemmed SLCDs, in the form of their forged Friends. In smaller sizes these units have several drawbacks, namely their lack of strength when placed in shallow placements. Old-school climbers would often add a short tie-off loop of Dyneema to the stem to overcome this. In larger sizes (3 to 4) these cams come into their own, being very strong, cheap, robust and relatively lightweight. Sizes 3.5 and 4 are highly recommended.

Weight

Everything revolves around weight, and it would be foolish to ignore this when choosing cams, as they are probably the heaviest items on your harness and you will often be carrying several units.

A saving of just a few grams per cam adds up, especially on long approaches or in the mountains. The biggest weight savings occur with the larger sizes. Practical details matter too, such as the benefit of an adjustable 30cm sling rather than a fixed 10cm, which can save carrying extra quickdraws.

Most modern SLCD designs aim to be lighter than the competition, but it must be accepted that lower weight can mean reduced lifespan. Lighter materials and stripped-down designs have their drawbacks.

Price

SLCD prices vary wildly, leading to confusion over security and strength. How can a £15 cam be as strong as one costing twice as much? The answer is that all cams pass minimum CE strength tests, and most come from reputable factories operating with large safety margins.

The difference in price becomes obvious when cams are placed side by side. Budget models use basic components and construction, lacking extendable slings, colour coding or refined ergonomics. They are similar to cams we were buying for far more money ten years ago. They are still strong and reliable. What you pay for is refinement: smoother action, better handling and user-friendly features.

Head width

Head width, the sideways dimension of the cam rather than its maximum range, is a critical factor, especially in smaller sizes. Too narrow and the cam becomes unstable; too wide and it won’t fit shallow placements.

In finger sizes, the ideal head width is roughly the width of two fingers. If you can fit your fingers in, you can usually fit a cam.

Number of cams

Most SLCDs use four lobes, offering the best stability, contact surface area and adaptability to irregular cracks. Three-cam units (TCUs) remove one lobe to reduce head width, making them easier to place in tight or shallow placements.

TCUs are lighter but generally have lower holding power than four-cam units in ideal placements. The key question is whether you want a stronger piece, or any piece at all.

Cam stops

Black Diamond popularised the idea of passive strength in cams, meaning that even when fully open the cam could hold like a nut. This was largely due to their double-axle design. Early single-axle cams lacked this feature and could be damaged if loaded open.

Forged cam lobes later allowed manufacturers to replace fragile pins with solid cam stops. Most high-end cams now include them. While few climbers deliberately place cams fully open, stops add security if a cam becomes tipped or dragged.

Strength

SLCDs are extremely strong. Rather than breaking, they almost always fail by ripping out of the rock long before any component fails structurally. All cams sold in the UK meet CE strength requirements, providing a large margin of safety.

Camming range

Greater camming range generally means lower holding power, so a balance is required. A cam that fits everything would hold nothing, while a cam with bolt-like strength would require carrying dozens.

The standard camming angle of 13.75 degrees, calculated by Ray Jardine, remains widely accepted. Designs that increase range often sacrifice holding power, with some notable exceptions such as double-axle systems.

In practice the differences are small. Most climbers still double up on key sizes regardless. Once you leave the shop floor or pub debate behind, it comes down to personal preference.

SLCD tapes

The sewn slings on SLCDs are a vital part of their design. They reduce the chance of disturbing the placement, help prevent walking and allow easy identification.

For anything other than straight-up climbing, extending cams is still advisable. Units with extendable slings offer a real advantage, reducing the need for extra quickdraws. One often overlooked feature is clipping directly into the cam head itself, useful when aiding or when reducing fall distance matters.