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(#1970, 2101)

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 Yoke Chest Ascender from Kwikspace in 2014. I acquired another in 2017 as part of Bob Thrun’s collection.

Cam faceThe ascender is left-handed, as are most chest ascenders I have seen. The ascender is 117 mm. high, 79 mm. wide, 40 mm. thick, and weighs 158 grams. The ascender shell is subtriangular blue anodized 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 17 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, 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 21.5 by 18.8 mm. and the upper 17.0 by 14.3 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 pivot is centered 48 mm. from the inside of the rope channel.

The cam is a stainless steel casting with an open web. The cam radius increases from 38 to 57 mm. over an angle of 44°, giving a 28° cam angle. The cam has number of small conical teeth, all of which have their axes approximately aligned with the cam axle. The tooth pattern is (3)^3(1S1)^5(3)^2. The reverse side behind the cam face being sloped rather than parallel to the cam axle.

A spring-loaded manual safety tab 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.

The front of the Yoke is printed with "ROPE:Ø8-13MM," an arrow labeled "UP," the Yoke logo, and "12 TLT."


The Yoke is one of the following group of closely-related chest ascenders:

Image Ascender Cam Cam Safety
CIC CIC Symmetrical Aluminum /w Tab
Climb Tech Climb Tech Symmetrical Aluminum /w Tab
Epic Peak Epic Peak Symmetrical Aluminum /w Tab
Fixe Fixe Asymmetrical Aluminum /w Tab
GM Climbing GM Climbing Symmetrical Plastic-covered
International Safety<BR>Components RP229 International Safety
Components RP229
Asymmetrical Aluminum /w Tab
Image Ascender Cam Cam Safety
NTR NTR, Version A Symmetrical Aluminum /w Tab
Rock Empire Rock Empire Chest Symmetrical Plastic-covered
Vento (Венто) Vento (Венто) Asymmetrical Aluminum /w Tab
Xinda Xinda, Version A Symmetrical Aluminum /w Tab
Yoke Yoke Asymmetrical Aluminum /w Tab
Z&W Z&W Symmetrical Aluminum /w Tab

I obtained most of these from China. The others (e.g., the Rock Empire obtained from the Czech Republic, the Vento from Russia) were made in China as well. These are all well-made ascenders and the prices that I paid, even with shipping, were far below those of the European-made equivalents. One potential concern is that we don't have the experience with Chinese metallurgy and quality control that we have with American and European devices, but I have no evidence suggesting that the metallurgy is unacceptable and the quality certainly appears to be fine. I'm not making any recommendation on this point one way or the other.

All sharp edges have been removed, except for those on the inside of the attachment holes on a few of these. The user should round the attachment holes with a Swiss file.

The cams are all very well made. There are two distinct cam types, "symmetrical" and "asymmetrical." The reverse side behind the cam face is parallel to the cam axle on the symmetrical cams, and sloped on the asymmetrical cams. This has no practical significance. The asymmetrical cams have a (3)^3(2)(1S1)^4(3)^2 tooth pattern while the slot in the symmetrical cams is slightly longer (extending to between the top tooth pair), giving a (3)^3(1S1)^5(3)^2 tooth pattern. This also has no practical significance.

Another minor difference is that the cam rivet on the Yoke has a smaller head than the ones on the others.

All of these have aluminum tab cam safeties, but the ones on the GM Climbing and Rock Empire are plastic-covered. I don't find a particular advantage or disadvantage to the plastic tab, but one may have a personal preference. Mine is to save weight by choosing one without the plastic cover.