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How to Choose the Best Climbing Cams

Sometimes carrying many different brands of cams at once can be confusing if you're not familiar with the size and color of each one.
Tuesday January 30, 2018
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A camming device is often referred to as a "camming unit" or often just a "cam." Very few people refer to them by their complete name: Spring Loaded Camming Device or SLCD. The name comes from the fact that when weighted, the opposing lobes of the device cam outwards to form a secure piece of protection. A camming device is judged by how well these cams grab the rock in various types of placements.

For free climbing  it's nice to have cams with thumb loop  making them easier to grab or even bite.
For free climbing, it's nice to have cams with thumb loop, making them easier to grab or even bite.

Regarding strength, all the cams in our review are rated to 10 to 12KN in the larger sizes, capable of holding significant falls and making bomber anchors when placed correctly in high-quality stone. Smaller cams, especially in the micro sizes have less holding power, and distribute forces over a tiny area, making them more likely to break through weak or chossy rock and pull out. Always read the manufacturer information when you buy a new cam and know it's limitations. If you're new to climbing, try to go out with someone who's experienced to teach you how to place cams correctly. Many climbing gyms are beginning to offer introductory traditional climbing classes. Climbing is supposed to be fun! Learn how to use your gear correctly, be realistic about your limitations, and be safe. Also, wear one of these.

While the theory behind the proper function of camming devices is standard, we found that not all cams are created equal, and some are better for specific uses than others. Generally speaking, most climbers like to dabble in a bit of everything and will seek cams that can do it all: a healthy serving of Tuolumne, maybe a High Sierra summit, a pinch of Joshua Tree monzonite, a little zest of Red Rocks, add a dash of walling in the Valley and you've got a pretty standard California climber's recipe for enjoyment. Fortunately, there are many cams to choose from that will serve the regular climber well in any and all pursuits. Here are some of the main things we consider when shopping for cams:

Both the Totem (left) and the Alien (right) are great for protecting pin scars found in Yosemite and Zion.
Both the Totem (left) and the Alien (right) are great for protecting pin scars found in Yosemite and Zion.

Do You Climb in Areas with Pin Scars?

If you climb perfectly parallel cracks like in Indian Creek, most cams will work just fine, but cams with the most surface area on the lobes such as Wild Country Friends and Black Diamond Camalots are ideal. When it comes to pin scars, Cams with narrow heads and flexible stems work well and offset sizes work even better, since they better match the flared shape of the pin scar. Fixe Hardware Alien Revolutions, Black Diamond X4s, and Metolius Ultralight Mastercams are useful for protecting pin scars, and all are available in offset sizes. The Totem Cam is the new king of the pin scar, with a vast range and the ability to load each side independently, each cam can protect offset and parallel placements, eliminating the need to carry an additional run of offset sizes. We recommend Totem Cams to any veteran or aspiring El Cap climber.

Do You Protect Really Small Cracks?

Just about any cam works in a bigger crack, but when it comes tiny cracks, often only a couple types of cams will work. Some people exclusively use nuts when it comes to tiny cracks. But if you need cams for parallel placements in microcracks, only a few of the brands get down to the micro level. Often the smallest cams are only appropriate for aid climbing. Metolius Ultralight Mastercams, Black Diamond X4s, and the Fixe Hardware Alien Revolutions are available in the smallest sizes, down to .33 inches.

How Important Is Cam "Walking" to You?

Cam walking occurs when the movement of the lead rope is transferred to the cam and causes it to move around or "walk." If the cam walks in, it can become stuck and challenging for the second to retrieve. It can also move out of its intended placement into an under cammed position, compromising its ability to hold a fall. Three key features affect cam walking: stem flexibility, head width, and sling length. A cam with a flexible stem is more likely to stay in place. Just as a narrow head width helps a cam get into shallow placements better, it also makes it more prone to walking. Finally, cams with longer slings require fewer quickdraws and runners to keep them from walking. That said, the longer slings can also be annoying and get in the way. Some folks would rather have their cam more prone to walking than have to deal with big slings and a flexible stem. If you carry 10-12 alpine draws and extend your placements when appropriate, walking isn't much of an issue.


There are three main areas of a cam that wear out: the cams, the trigger wires, and the stem. If you are only free climbing, and you take care of your gear, most cams are going to be durable enough. If you aid climb a lot, however, durability is a much bigger issue. If the trigger wires are exposed, they are going to get beat up fast. Cams like the Black Diamond Camalot and the Wild Country Friends are larger, heavier, and more durable than smaller devices like Fixe Hardware Alien Revolutions and Totem Cams.

To climb the notorious Lord Caffeine  you'll need cams ranging from fists to fingers.
To climb the notorious Lord Caffeine, you'll need cams ranging from fists to fingers.

Cam Range

Cam range is how big or small a crack each piece will fit in. For example, some cams might be two inches wide when fully open and go down to 1.5 inches while another cam may start at two inches and go all the way down to one inch. The bigger the range, the more options each cam gives you. Double axle cams used to have the most range, but now there are new ways to create even more range in each piece. While a big range is nice, it's not as simple as "The bigger the range, the better the cam." Cams with double axle designs such as the Black Diamond Camalot Ultralights, DMM Dragon Cams, and Wild Country Friends have a greater range than single axle cams. The double axle design allows larger lobes to be retracted to a narrower position.

Even if every cam on your rack has a vast range, you don't necessarily have to carry any fewer cams. You still need a lot of protection pieces to climb a pitch safely. The big range just makes it so you are less focused on conserving gear up the pitch. So if the way a cam allows for more range is by making the cam heavier, you may end up with a more substantial rack by carrying cams with a more significant range. We do like the idea of having a few massive range cams saved for the top of the pitch where you might be running low on gear and just need to throw things in. Also, if a cam has a more extensive range, it usually does not work as well in shallow placement.

Cam Angle

Every manufacturer chooses a slightly different cam angle for their cams and has a reason why they think it is the best. For example, Metolius says that all their cams have an "Optimized cam angle for more outward force," which implies their cams should hold better than other cams. We don't know of a way to evaluate this in the real world. Anyone with an engineering degree could argue why one cam angle is superior to another in a lab environment. But there are just too many other factors to isolate whether the Metolius cam angle makes it hold better. In our subjective tests, we find that differences in cam angle probably only make a big difference in a lab or a perfect parallel crack.

In the real world of climbing, more critical than cam angle is how well the cam can get placed. Does the axle design let it get into tricky spots? Does the head width allow it to fit in the pod completely? Is the stem flexible enough to transfer the force down rather than levering it out? There are so many different factors affecting how a cam holds in the rock during a fall. Cam angle is just one of them, and we don't think it alone is a reason to buy one cam over another. We also don't know of a way to evaluate who has the best cam angle.

Same Cam Brand or Mix and Match?

Most climbers shouldn't worry about what one set of cams to buy. Instead, you should think about what set of small cams are right for you (sizes .33-1.25") and what kind of medium to large cams you want (sizes 1.5-5+"). We do not recommend carrying more than two brands except in the specialty sizes (huge and micro sizes). Those sizes you generally aren't going to use as often.

What brand to get is a big decision. Once you commit to a brand, you typically want to stick to it as you expand your rack. This will help you when you're figuring out which color corresponds to which size crack. Having a rack of mixed and matched cams of multiple brands can make it difficult to know what to reach for, but not impossible. After climbing for a long time, you'll develop a sense for all the subtleties in sizing of the different brands, and buying cams based on what's on sale can be a good strategy for the penny-pinching dirtbag trying to build a complete rack. Your partners may curse you for this, and most people try and limit their rack to one or two brands. On the bright side, more and more companies are switching to a "standard" color size. So a yellow cam in one brand is about the same size as a yellow can in another, but we still recommend taking your time to find your favorite brand and then committing to it.


Weight used to be more of an issue, but today most cams are pretty light. Black Diamond Camalot Ultralights and Metolius Ultralight Mastercams are exceptionally light, and both brands are a good choice if weight is a major concern for you. All those cams start to feel pretty heavy when you are carrying a massive rack. People who climb in environments where every ounce counts (alpine climbing) should consider weight. Otherwise, the performance of a cam is much more important.

Both DMM and Wild Country make cams with extendable slings.
Both DMM and Wild Country make cams with extendable slings.

Length of Slings

All cams come with a built-in sling, but some brands offer an extendable sling option, allowing you to protect wandering pitches and reduce cam walking without having to carry as many quickdraws. This saves the leader time and means you can climb with fewer carabiners and runners. The downside to extendable slings is they can be a little difficult to "de-extend" by the follower on the go, with one hand. With practice, it's not too hard, but if you're pumped and intent on following a pitch free, you'll have a bunch of cams swinging around low on your harness as you thrash your way up the pitch. The DMM Dragon Cam has the longest extendable sling, and also a cool thumb piece that allows for the Dyneema sling to extend without any loss of strength.

Dragon Cams feature a nice long extendable sling
Dragon Cams feature a nice long extendable sling

Check out our complete Climbing Cams Review to see how the top cams score against each other.

History of Climbing Cams

For the modern rock climber, it's hard to imagine starting up a climb without at least a dozen different camming devices clipped to your harness. Today we have a huge variety of brands and styles of spring-loaded camming devices or SLCD's (we typically just call them "cams" these days). But the modern high tech cam made with space-age metal alloys and perfectly machined pieces is a surprisingly recent invention in the long history of rock climbing Few inventions have revolutionized the world of rock climbing like the advent of cams.

Spring Loaded Camming Devices are a fascinating piece of engineering and machining mastery. The quarter circle lobes of cams are based on a logarithmic spiral, a spiraling pattern that we find in nature with abundance. We see the logarithmic spiral in the twisting shape of seashells and in the galactic spinning pattern of our very own Milky Way Galaxy. By basing the lobes on this spiraling design, it allows the cam lobes to contact the rock at the same angle regardless of how open or closed the cam is placed. There is a delicate balance between the size range a cam can span and its holding power. If you increase the range of too much, it increases the angle at which they contact the rock, this, in turn, reduces the force applied outwards by the lobes, thus reducing the holding power. So striking a fine balance between the range and the required force for maximum holding power is a vital aspect of the design.

Most folks credit the first SLCD designs to the famous mountaineer Greg Lowe in the early 1970's; however, the Russian climber Vitaly Abalakov was working on a similar idea across the globe around the same time. In 1972, Greg Lowe developed a now comical "cam nut" which was a single lobe attached to a single stem. While functional, the design was difficult to place and proved to be relatively impractical. Soon after the Cam Nut Lowe added a second lobe to the design for a single stem, two-lobed "Split Cam." Again, the idea was extraordinarily inventive but failed to gain mainstream interest.

By the mid-1970s, several other inventive climbers of the day had begun to work on futuristic designs for rock climbing protection to replace the passive hexentrics, stoppers, and chocks most commonly used at the time. It took an inventive and eccentric aerospace-engineer-turned-rock-climber by the name of Ray Jardine to come up with the breakthrough design that would change the face of climbing forever.

Jardine had concluded that the SLCD design needed to be exceptionally strong with a great strength to weight ratio, it needed to be manipulated with a single hand, and it required a significant range to protect multiple sized cracks with a single piece of gear. By about 1975 Jardine had his first prototype cams which quickly became known as "Friends." Climbing Magazine reports that Jardine required absolute secrecy from his select group of climbing partners during the development of the first Friends. When meeting up to go climbing for the day a large group of climbers was present when one of Jardine's partners began to ask if he had brought the cams. Mid-sentence he realized he shouldn't mention them, so he asked if Jardine was going to bring any "Friends". The name stuck and in 1978 Friends hit the market. Their first advertisement appeared in the magazines with the slogan "Get High with a little help from your Friends" in January 1978.

The release of Friends was one of the biggest game changers in rock climbing history, alongside sticky rubber climbing shoes which were released in 1982. No other inventions have caused such dramatic advances in the sport. The first Friends came in 4 sizes, starting at a tight hand size (about two inches) and spanning up to fist-sized cracks measuring four or five inches. Soon Jardine released several more cams to protect cracks down to finger sizes and to cover the sizes between his existing 1, 2, 3 and 4 Friends. Within a few years, other inventive climbers across the nation and around the world were looking to improve the design of Friends.

Climbers were primarily interested in creating a camming unit that could cover the sizes much smaller than what the Friends protected, cracks below about three-quarters of an inch. Steve Byrne created Wired Bliss out of Flagstaff Arizona and was one of the first to find the engineering solutions to these tiny cams. Byrne successfully designed a tiny rigid stem cam. He manufactured over fifty of them, and the legendary Alan Watts took them to Yosemite where they sold like hot cakes. The smaller the placements became, the more that the rigid stem would hinder performance, so Byrne began experimenting with replacing the stem with a cable to create a more flexible unit. This idea gave birth to an SLCD that only had three lobes, instead of four, and had a U-shaped stem instead of the typical straight stem. These became widely known as TCU's (three cam units) and were the smallest cams on the market for many years.

During the 1980's, several different companies released slightly different versions of the same thing. Because of Ray Jardines patent on the basic design of Friends, other companies were forced to create variations to the trigger and stem, fueling many innovations over the years. In 1987 Black Diamond joined the list of companies selling different versions of cams. However, the Black Diamond "Camalot" was unique. The lobes of the Camalot were not set upon a single axle as all other cams had been. They possessed a double axle which improved the range substantially without decreasing the holding power. Over the years this design has seen several improvements but is still based up the same sizes and double axle design. The Camalot remains the gold standard of rock climbing protection today.

Today there are many different SLCDs on the market, and all provide excellent protection and safety. Black Diamond has released C3's, a futuristic three cam unit that comes in incredibly small sizes and the new and impressively flexible X4s. Colorado Custom Hardware (CCH) pioneered the flexible cable stem in the 1990's creating an extremely flexible device with springs integrated into the lobes which allowed for an incredibly narrow width to the head and lobes. CCH was also the first company to use two different sized lobes, called offsets. One set of lobes is a size smaller than the other which allows for incredible holding power in flared cracks and piton scars, these have become an essential tool in Yosemite Valley and on big wall routes around the world. Recently Totem Cams reinvented the cam with an incredible design that offers a whole new lobe shape allowing for unsurpassed security in irregular and flared placements. The Totem Cams are quickly becoming the protection of choice among climbers on the big walls of Yosemite Valley and the strange, flaring limestone routes of Europe. Whichever piece of protection you choose, remember how lucky we are to reach for a lightweight, strong and easy to place spring-loaded camming device instead of always grabbing for those stoppers and hexes.

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