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

Technical Details

I acquired my Spent Ruční from Ondřej Belica in 2013.

The Spent Ruční ("Ruční" = "hand") is 197 mm. tall, 94 mm. wide, 28 mm. thick, and weighs 210 g. The shell is a tall irregular shaped stamping made from 3.75 mm. aluminum alloy sheet metal. A rope channel is formed in the upper portion of one side and a smaller cam channel lies opposite the first. The rope channel is 15 mm. wide. A hole drilled through both sides of the cam channel accepts a 5.5 mm. semi-tubular rivet. The cam and cam spring are mounted on this rivet. The handle below the cam has a soft black plastic hand grip riveted into place. The hand grip has four finger grooves. A 15.3 mm. sling attachment hole is punched below the handle opening. An 18.7 mm. hole through both sides of the rope channel provides an attachment point just above the cam. A second hole above the cam is 11.2 mm. in diameter. All these holes are slightly beveled.

The cam is milled from plate aluminum alloy. The cam radius, measured from the pivot, increases from 39 to 51 mm. over an angle of 41°, giving a 22° cam angle. The tooth pattern is (3.2)^5. Each tooth is a hardened steel pin, sharpened and pressed into a hole drilled in the cam face. Like many other ascenders, the inner cam face radius reduces from top to bottom to accommodate various sized ropes. A spring-loaded manual safety bar is mounted in a slot on the bottom of the cam with a solid pin. 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 knurled knob on the safety bar assists in operating the safety mechanism.

The front of the ascender is stamped with "Spent," "¥9-12mm," "CZECH." and "max.400kg." The rear is stamped with "SP-1/11002283" and "K."

Comments

Ondřej sent me the following information:

Used to be produced by company "Spent - záchranná, transportni a kotevni technika" (Spent rescue, evacuation and anchoring equipment).

At the beginning, the producer Vitek Novak was making some vertical devices at home just for himself and some friends around him. After the revolution in 1989, he founded the company Spent to produce it for sale. He started to produce pulleys (not so well done because while loaded the sideboards were collapsing, so they would brake the wheel of the pulley). He was making tripods, ascenders, descenders (similar to Stop Petzl, the funny thing is that the rubber holder was from bike handlebar). In some points he tried to copy Petzl, but to avoid breaching the patent, he modified the design.

The biggest problem with Spent was that the company was limited with machinery, so he wasn't able to realize some of his plans and ideas. Spent ceased to exist after 2001. See the technique used for making the teeth in the cam. The way of producing them is very interesting.

The teeth are unique. They make a very robust design, but I imagine that they were not a particularly economical option for manufacture. On the other hand, this design could be used for short runs in a well-equipped home shop.

I feel that this is a well made ascender. The rivets holding the hand grips in place have cracked ends. These are sharp enough to scratch my fingers, but they are recessed enough that I can ignore them; otherwise, all sharp edges have been removed. The cam teeth are very well done. The attachment points are simply holes in the shell, and although well rounded I consider their small radius too sharp for directly attaching sling ropes. They are probably acceptably rounded for webbing, but considering the proximity of the attachment points to the main rope, I would recommend using a small maillon for most attachments in order to reduce the risk of sling abrasion. The lower attachment hole could theoretically have the same safety problems as the one on Clog Version A. The upper rope attachment hole is located very close to the main rope. A carabiner through the upper attachment hole may drag on the main line. Note that such a carabiner will prevent putting the Spent on or off rope, so one’s climbing system must be designed accordingly.

Single-handed operation of this ascender is rather difficult with the either hand. Closing an locked open ascender is much easier than opening, since the strong cam spring assists the user.

This ascender has the same pit lip disadvantage as the Clog.