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

Technical Details

Ondřej Belica donated this ascender to my collection in 2022.

This ascender is 196 mm. tall, 90 mm. wide, 31 mm. thick, and weighs 172 g. The shell is a tall irregular shaped stamping made from 3.9 mm. aluminum alloy sheet metal. A 15 mm. rope channel is formed in the upper portion of one side and a smaller cam channel lies opposite the first. 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. There is no hand grip on this ascender. A 15.2 mm. sling attachment hole is punched below the handle opening. A 22.9 by 15.9 mm. oval hole through both sides of the rope channel provides an attachment point just above the cam. The second hole above the cam is 15.2 mm. in diameter. All these holes are slightly beveled.

The cam is a skeletonized steel casting. The cam has number of small conical teeth, all of which have their axes approximately parallel to the lower surface of the cam. The tooth pattern is (F)(3.4)^3(3.2)^2(3). The F stands for a short flat area designed to allow the user to cant the ascender and slide it down the rope without opening the cam. The outside two bottom teeth on the left ascender are barely visible, while they are full size on the right. Like the 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 on the bottom of the cam with a steel semi-tubular 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 are no markings on this ascender.

Comments

Ondřej sent me the following information:

As for the red ascender (similar to Spelet), I do have some information, but I haven't been able to verify it yet. I'll let you know when I do.

In a second message, he wrote,

I have information that it was made by Jiří Vlček, who worked in Motorlet (Walter), but a guy who used to know him said that he didn't know that Jiří was producing ascenders.

For now, I'll continue listing this ascender as an unknown.

Aside from the shape of the safety and the lack of a hand grip, this ascender is nearly identical to the Spelet Horní

This ascender is a close copy of the early Petzl Ascensions, including the cam flat appearing on the Petzl Ascension versions B and C. The flat area on the Petzl cam has caused some confusion. Some cavers think this was a design defect (Ondřej shares this view), but it was provided as a feature. The flat area allows one to cant the ascender then slide it down the rope without opening the cam, provided there is no carabiner in the rope channel holes.

I feel that this is a reasonably well made ascender for its time and place, although mine have seen considerable use. 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. This ascender has the same pit lip disadvantage as the Clog. 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.

Single-handed operation of this ascender is moderately challenging with the proper hand. This is partly due to the geometry of the safety and partly because of the strong spring. For the same reasons, operation is quite difficult with the opposite hand. Closing an locked open ascender is much easier than opening, since the strong cam spring assists the user. The cam is reasonably well made.