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(#2913, 2914)

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 one Tupa from Ling Rukuan of Yuanyiguang Technology and another from Denret3rgu on Amazon, both in 2019.

Cam faceThe Tupa is 114 mm. tall, 79 mm. wide, 33 mm. thick, and weighs 145 g. The ascender shell is a subtriangular anodized aluminum stamping 3.85 mm. thick. The rope channel is formed by bending the right side of the ascender into a U. The rope channel is 15 mm. wide. The main sling attachment point is located below the cam and behind the rope channel. A second attachment point is located above the cam and 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 lower attachment point measures 27.7 by 25.3 mm. and the upper 26.7 by 20.0 mm. The left end 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, cam spring, and a spacer washer are mounted on this rivet. The pivot is centered 49 mm. from the inside of the rope channel. There is no cam stop.

The cam is a plated skeletonized steel casting. The cam radius increases from 40 to 54 mm. over an angle of 36°, giving a 25° cam angle. The cam has number of small conical teeth. The upper teeth are parallel to the top of the cam, but the lower teeth have their axes sloping downward. The tooth pattern is (3.4)(1S1.1S1)(4)(1S1)^3( where the S stands for a central slot.

A spring-loaded aluminum manual safety tab is riveted to the cam. The normal action of the safety spring holds the safety against the cam. When the cam is opened, the shell interferes with the safety, thus preventing opening the cam. If the safety 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.

The front is printed with an up-pointing arrow, a logo, "TUPA,"expand climbing," "ROPE 8≤Ø≤13MM," and "Max 140KG." The rear is printed with "CE" and "EN 567:2013."


In general I feel that this is a well made ascender. All sharp edges have been removed. The cam teeth are rather well done. The thumbs tab is large with a textured surface to help give the fingers a better grip.