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

Technical Details

I acquired this pair of ascenders new from Jeffrey Neff in 2005. I acquired another pair in 2017 as part of Bob Thrun’s collection.

The shell is a tall irregular shaped stamping made from 4 mm. aluminum alloy sheet metal. A bend forms a rope channel 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 mm. semi-tubular rivet that supports the cam and cam spring. The round head of the rivet lies in front, while the roll is exposed on the rear. The handle below the cam has a soft black plastic hand grip molded into place. The hand grip has four finger grooves. A 16.3 mm. punched sling attachment hole lies below the handle opening. This hole is not beveled. A 16 by 19.2 mm. hole through both sides of the rope channel provides an attachment point just above the cam. Neither hole is beveled. A C-shaped area punched from the rear of the shell serves as a cam stop

The cam is a plated skeletonized steel casting. The cam has number of small conical teeth, all of which have their axes approximately parallel to the upper surface of the cam. The tooth pattern is 3(4.H)^2(3.H)^2(2.2.1), where "H" indicates a hole. 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 somewhat cracked 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 bent tab on the safety assists in operating the safety mechanism.

The plastic hand grip has "Omni USA" molded into both sides.

Comments

The workmanship on this ascender is acceptable but not exceptional. There are no true sharp edges, but no real rounding either. 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 ascender on or off rope, so one’s climbing system must be designed accordingly. The cam stop is placed where it works, unlike the nonfunctional cam stops found on the Kong-Bonaiti and the Petzl Ascension Version D.

The cam looks better-made than the shell. The cam teeth are very well done. The cam looks like it was based on the Kong Modular cam but the Omni USA cam looks better cosmetically. The inside of the cam face is not beveled like it is on the Kong Modular.

Single-handed operation of this ascender is not as easy as it should be with the proper hand, and is rather difficult with the opposite hand. I think that the geometry of the cam channel requires opening the cam safety farther on the Omni USA than on, say, the Kong-Bonaiti or Petzl Ascension. The rough edges on the Omni USA stampings give a grating feel not found with the smooth surfaces on the Kong-Bonaiti and Petzl Ascension. Closing an locked open ascender is much easier than opening, since the strong cam spring assists the user, but again, the Kong-Bonaiti and Petzl Ascension actions are smoother.

This ascender has the same pit lip disadvantage as the Clog and others. The cam does not have reinforcing stamped depressions like the Kong-Bonaiti and Petzl Ascension do.

Overall, the Omni USA is adequate but slightly inferior to the Kong-Bonaiti and Petzl Ascension.