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Singing Rock Sir

Front Rear
Front Rear
Front: Open for Rigging Rear: Open for Rigging
Front: Open for Rigging Rear: Open for Rigging

Technical Details

I acquired my Singing Rock Sir from in 2015.

The Sir is a shaped like a flattened and deformed avocado. Mine is 126 mm. tall, 73 mm. wide, and 36 mm. thick. It weights 366 g.

The Sir consists of four major components: the body, the rotating cam, a cover plate, and an actuating lever assembly. The body and cover plate are forged from aluminum and then hard anodized. Superficially, they are mirror images of each other, although there are some details where this symmetry breaks down. In other, more practical words, the front cover and rear body are roughly the same thickness, and the seam between the two splits the closed device in half. A 6.4 mm. stainless steel rivet joins the front and back near the top. Each piece has a plastic insert, and the inserts are shaped so that with the covers closed, the inserts form a groove for 10 mm. diameter rope. The cam assembly pivots on a roughly 15 mm. stainless steel axle attached to the body. The attachment method is not clearly visible. A spring-loaded button protruding from the cam axle passes through a hole in the front plate when the cover is closed. The bottom of the body and cover have aligned 18.3 mm. holes that form the attachment point. The body has a plastic anvil next to the hole. The anvil has a U-shaped groove for the rope to run over. The anvil and lever assembly are held by a 5 mm. stainless steel rivet.

The rotating cam is cast steel. It has a webbed design with several reinforcing ribs. The right side of the cam has a rounded V-shaped rope channel with about a 6 mm. minor diameter at the base of the V. The left side has two small grooves to provide a finger grip for feeding rope. The bottom of the cam has a flat area that squeezer the rope against the lower anvil when the cam rotates counter-clockwise (i.e., closes), as it would when stopping a fall.

The lever assembly consists of a yellow control lever connected to the cam by a steel link. Pulling the lever downward forces the link upward, opening the cam; however, once the lever passes a certain point, the link disengages and the cam rotates closed again under rope tension. At this point, raising the lever opens the cam; but again, the action stops if the lever moves too far.

The cover is printed with an up-pointing arrow, "singing rock," "CE0123," a drawing of the rope path with an anchor icon at the top and a hand icon at the bottom, a double ended arrow with "press" at one end and "&push" at the other (i.e., opening instructions), "SIR," a book-with-an-"i" icon, "0263/0214," "EN 12841 - Type C," "¤10-12 mm, 225 kg," "EN341:2011/2A," "¤11mm Singing Rock Static R44," "30-180 kg/max 190 m," and "-20°C≤T≤+60°C." The cam has a raised climber icon. The lower anvil has a molded hand-holding-a-rope icon.


The Sir has excellent workmanship and it functions well. It is solid, but it is also quite heavy. This should not be a problem for gym climbers or people who drive to the base of short sport climbs, but I wouldn't consider lugging this one to a remote climb or up a wall.

The lever action has one curious feature: once the belayer moves the lever past the release point, the lever function reverses. In other words, I would normally lower someone by pulling down on the lever, with farther down meaning a faster lower. If I pull too far, then the cam locks. At this point, I would resume lowering by pushing the lever up , with farther up meaning a faster lower. If I go to far again, the action reverses a second time, and the lever operates as it originally did. Sort this out at home, not at the cliffs.

The lever function provides partial backup for the belayer not knowing how to use the lever, but like all such devices, it relies on the belayer being completely incompetent rather than partially incompetent - by definition, a partially incompetent belayer would drop me too fast without moving the lever past the release point. I'm not convinced that this sort of feature is an improvement on selecting a competent belayer - or not falling in the first place.

The lever assembly is greased. This grease will pick up sand and dirt.

One can feed rope out rather easily by manually lifting the cam with an index finger. Taking rope in is even easier - just pull it through the device.

The Bornak Lory, Edelrid Eddy, abd Singing Rock Sir are essentially the same device, but some parts on the Eddy are steel while the corresponding parts on the Lory and Sir are plastic.