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Front View: Closed Rear View: Closed
Front View: Closed Rear View: Closed
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired my Апыурс in 2017 as part of Bob Thrun's collection.

The Апыурс is left-handed. The ascender is 115 mm. high, 78 mm. wide, 40 mm. thick, and weighs 142 grams. The ascender shell is subtriangular shape bent from 4 mm. aluminum sheet. The rope channel is formed by bending the right side of the ascender into a U. The rope channel is 15 mm. in diameter. The main sling attachment point is located below the cam and behind the rope channel. A second attachment point is located above the cam, also behind the rope channel. The shell is bent backwards at both points to provide clearance between the attachment slings and the main rope. This accounts for the rather large thickness of this ascender. The attachment points appear to be ovals distorted by the stamping operation. The lower attachment point measures 22.7 by 17.1 mm. and the upper 16.5 by 12.3 mm. The left side of the shell is bent on an inclined axis to form another U. A hole drilled through both sides of the U accepts a semi-tubular rivet. The cam and cam spring are mounted on this rivet. The head of the rivet sits on the edge of a stamped depression on the back of the cam (clearly off-center from the intent), while the roll is exposed on the open side. The pivot is centered 48 mm. from the inside of the rope groove.

The cam is a skeletonized steel casting. The cam radius, measured from the pivot, increases from 37 to 53 mm. over an angle of 39°, giving a 28° cam angle. The cam has number of small conical teeth that slope downwards with respect to the cam face. The tooth pattern is (2.2)(2S2.1S1)^2(1S1)^3(1.2). A spring-loaded manual safety bar is mounted on the bottom of the cam with a steel rivet. The normal action of the spring holds the safety against the cam. When the cam is opened, the shell interferes with the safety bar, thus preventing opening the cam. If the safety bar is moved away from the cam (opposing the spring), it will clear the shell and the cam will open. At full open the safety can be released and the spring will hold the safety against the back of the shell. This provides a means of locking the cam open. A knob on the safety bar assists in operating the safety mechanism. There is a cylindrical cam stop attached to the shell above the cam.

There are no markings on this ascender other than a printed sticker. The sticker has "Туристическая Фирма" (Tourist Company), a logo, "Апыурс" (transliterates as Apyurs) "630064 r. Новосибирск" (Novosibirsk), "уп. Ватутина" (the Belgorod area), along with telephone and fax numbers.


The Апыурс is rather roughly constructed, but not to the point that it interferes with operation or safety. The cam rivet does not align with the depression provided for the rivet head. There are some tool marks from bending the shell, and some holidays in the cam casting, but these are minor. All sharp edges were removed, and the cam works smoothly. The cam on mine shows traces of surface rust on the inside of the web.