In this review Jaz Morris discusses what he's learnt about different models of offset cams during a long season trad climbing on North American granite. We couldn't find any comparison reviews on the internet so we hope this will fill a bit of a gap!
Pin scars, flaring cracks and fusing seams of rock have long been the bane of the desperate aid-climber or the run-out trad leader, but these can nowadays be protected quite securely by offset cams. Although they have in fact been around for a fair while, they might be unfamiliar to many kiwi climbers. Aliens, Metolius and more recently Black Diamond cams all offer offsets among their range, where on each cam one pair of lobes is the next size up from the lower pair. In addition, Totem cams can also be placed in an offset mode, whereby full cam strength is retained even if one pair of lobes is undercammed with respect to the other pair. I've recently spent a bit of time in Yosemite, where I rapidly discovered that a set (or two) of offset cams is an essential part of any aid rack. The dark years before clean climbing have left many routes blemished by repeated piton-bashing - so-called pin scars tend to flare outwards or constrict downwards, often making for tricky pro on classic Valley climbs like Serenity Crack and on the lower pitches of The Nose. Offset cams are increasingly finding themselves being carried on my normal trad rack too, especially in the smaller sizes. The smallest cracks, in my experience, seem to seldom be perfectly even, and usually constrict somewhere, so I've taken to carrying 0.1/0.2 and 0.2/0.3 offsets (Black Diamond sizing) in addition to (or even instead of) regular 0.1 and 0.2 pieces. Microcams always seem more prone to ripping out, so being able to sneak them into constrictions adds a welcome extra element of security. And if you've ever cleaned an aid pitch protected by bounce-tested wires, you'll quickly appreciate the alternative option of placing easy-to-remove cams in constrictions instead.
On to the cams themselves. The basic design between manufacturers is pretty similar - they have bendy stems, as narrow a head as possible, and are available up to around 0.5-0.75 inch size. Offset Black Diamond X4s are the most recent addition to the market, and bring a couple of key innovations. Those familiar with BD's size/colour arrangement will appreciate the differential lobe and sling colouring on the offset X4s, making it easy to see which cam is which on your rack (although the difference to the eye between the blue/grey 0.3/0.4 cam and the grey/purple 0.4/0.5 cam is fairly subtle). With dual axles on the BD cams comes a greater camming range per piece, but at the expense of greater head width in the small sizes, compared to Aliens. They cover 8 - 41mm cracks with five cam sizes.
Offset Aliens, available these days under the Fixe or techRock names (previously they were made by CCH) carry the familiar thumb loop and highly flexible stem familiar to Alien aficionados that makes them easy to place and keeps them from walking. They are light and have a very narrow head width (30mm across all sizes), giving them perhaps the best chance of the lot at fitting narrow pin scars. But, with relatively soft lobes, they trade off easy and secure placements for reduced durability. I've managed to completely mash one in only a few big walls, so as much as I like them, I wouldn't make them my sole brand of offsets unless my discretionary income increased several-fold. Aliens cover 8-33mm cracks with six cam sizes, making a 'just right' placement more likely than stretching the design specs of the greater-ranged X4s, but of course that means you need to own more of them.
Metolius now produce offsets of the same broad design to their ultralight Master cams. For those that preferred the older design with a thumb loop, like me, this will be a disappointment. I haven't used the ultralight versions much but recently became enamoured with the older version - they are durable and always seem to give secure, no surprises placements. Strung out on some monster C3 pitches on El Cap's 'Tangerine Trip' I always kept my climbing partner's set of Metolius offsets in reserve for the sketchiest placements, burning up offset X4s in less critical moments. Offset Master cams protect 9-40mm cracks with six cams. Metolius also make offset TCUs (three-cam units) if you really want to expand your rack, but I'm not sure the narrow head-width is worth the trade-off in security in this instance.
Totem Cams operate somewhat differently, but function well as both offset and regular cams due to the way that the sling equalises the load from the top and bottom lobe pairs (rather than loading all four lobes as one unit). Even more remarkably, one can even place Totems with only two lobes engaged, providing some novelty as you contemplate the ultimate peril. Totems have been reviewed and evangelised in many previous reviews, suffice to say these carry serious design advantages over all other cams for free and aid climbing purposes. But (you knew there was a 'but') they are really expensive ($150+ NZD each, or so) and difficult to come by. They are in vogue in the USA at the moment - I've spent the northern summer trying to track them down and only succeeded after many months - the standard response from climbing store clerks is to scoff and say "we wish we had those in stock." They cover 12-64mm cracks in seven sizes, so have by far the greatest size range of any cam with offset ability, but it's worth noting that you could buy a road-legal car for about the same amount of money as seven Totem cams.
So, should you buy offset cams? And if so, which type? To answer the first question: yes, only if you already own a decent rack and anticipate an aid climbing future. At a stretch, I'd suggest getting a couple of offsets as part of your second rack of cams rather than doubling standard cams, in particular in the small sizes and if your local rock frequently offers up creative gear placements. To answer the second question: it depends on a couple of factors. Buying Totems is certainly the best option. But for regular offset cams, X4s are available in a greater spread of stores (they are even available in NZ), and the dual colouring makes them the easiest to to get your head around. But, if you come across an older set of Metolius offsets, snap them up. I've never warmed to Aliens the way others have - and they don't seem to me to last as well in Valley granite. Really, though, these are all specialist kit made well. All the true offset cams reviewed here have little meaningful difference in weight or price, so perhaps durability and range per cam (whether you want fewer cams to cover the same range, or want more 'just right' placements) should be your key decision making factors.
Ratings out of 5 stars (and approx cost in USD):
Black Diamond offset X4s **** ($70) - link to manufacturer as at 11/2018
Aliens **** ($65) - link to manufacturer as at 11/2018
Metolius *** - older version ***** ($60) - link to manufacturer as at 11/2018
Totems ***** ($90+) - link to manufacturer as at 11/2018