The 4 Cam Unit Set by DMM. The DMM 4CU's light weight is a noticeable advantage when packing in or climbing with a full rack. The way we see it, an average 20% weight saving means that the climber can "sew up cracks" with a much lighter rack. Another way of looking at it is that climbers can place 20% more cams, feel much more secure, and still come out even on the weight. Less weight with more protection ... who wouldn't love that?
Each cam is rated to 14 kN in the active, working position with the quick release sling doubled, and 12 kN with sling fully extended. The passive strength of the cams, resting on their stops, is 10kN.
The cam lobes are cut to a 13.75 spiral. This has proven to be the best angle for balancing a cam's range and holding power. Our cam lobes are anodized for easy, size identification on the rack. After all, time is of the essence when you're on a pumpy route.
The "free-floating" axle is peened, not soldered to the cable terminations, to allow them to rotate as necessary at the moment point of impact. This reduces stress and helps to avoid a sheering torque on the axle. This effect is especially obvious if you imagine placement in a diagonal crack, although it will happen in almost any type of placement. In a diagonal the cables sides take uneven pressure and will rotate in opposite directions from one another. On point of impact, the torque on the axle is minimized by our peened construction.
The trigger bar is able to slide on the trigger wires to reduce wear and tear on the wires. If a camming unit is placed in a flared crack, the cam lobes are commonly set with one pair of cam lobes tight and the other pair loose. The trigger wires on the tighter pair's side are able to slide through the trigger bar, instead of getting wadded up, crimped and frayed, as on other brands' units. Occasionally, a placement causes the trigger bar of a unit to rub against the side of the crack. Here again, this is a time when your DMM 4CU trigger bar can slide up the wire, avoiding the crumpling effect that happens to triggers that are stationery on other brands' wires. One more example of this anti-wadding effect is when a rack is crammed into a backpack, the trigger wires on DMM cams do not get as compressed and tweaked, because of our well thought out, yet simple design.
What are the two empty holes in the trigger bar? They are there for the crack connoisseur who wishes to sling 2 mm cord in a U-shape configuration, echoing the U-shaped cable construction. This serves as a retractor cord for cams that have been placed too deeply into a crack.
DMM 4CU's come in 11 sizes, fitting from 0.5 inch to 4 inch cracks (13 mm-100 mm). Our size designations approximate the corresponding crack size in inches. We have two sizes that are unique to the DMM and Wild Country ranges, 1.25 and 1.75. These fit in between the more common 1, 1.5 and 2 inch units and cover those otherwise sketchy, off-fingers and narrow hands sizes.
Our 4CU's have an amazing range of features that make them quick, light and easy to use. They're light, strong, secure, durable and quickly identifiable for size.
Colour coded Spectre and Phantom carabiners are available so that you can rack your cams in an easily identifiable manner.