More About Ascender Handles

The U.I.A.A. once set a standard defining a minimum acceptable size for an ascender's handle. The standard included a minimum hand opening size defined by the area obtained by drawing a 20-mm radius top circle and a 15-mm radius bottom circle whose centers are 60-mm apart, and then connecting the circles with the common tangents as shown in the figure. I prefer to think in terms of the overall length of the opening and the diameters of the circles, so I'll refer to this as the 95-40-30 shape.

I can't take this standard very seriously, for some of the following rather obvious reasons:

• There are a number of handleless ascenders that work perfectly well, so obviously the minimum acceptable size is 0-0-0.
• Many of the climbing systems that use handled ascenders do not use the handles directly. If one isn't going to grip the handle, then the size of the handle does not matter.
• People have different size hands, so what is so special about this size? For example, it's certainly too small an opening for my hands to completely fit inside.
• Even if a particular person with a particular size hand is going to grip the handle, the size depends on how they are going to grip it (fingertips? fingers? whole hand?)
• Given a particular hand and a particular grip, the size needed also depends on whether the hand is wearing gloves or mittens, and how large these are.

Nevertheless, I thought it might be amusing to define a few other shapes and compare the various ascenders. I made six different "handle size gages" out of wood, and used them to test the opening for each handled ascender in my collection. All of these were designed by connecting the tangents of two circles in the same manner as the U.I.A.A. defined their handle standard. In addition to the U.I.A.A. gage, I made the following gages:

Code	Size	What fits
60-20-20	Tiny	Two or three of my fingertips
80-30-30	Small	Three of my fingers, fully inserted
100-30-30	Ample	Four of my fingers, fully inserted to palm
110-35-30	Large	Four of my fingers, wearing leather gloves, fully inserted
120-50-40	Huge!	Four of my fingers, wearing expedition mittens, not badly compressed.

Needless to say, these sizes are completely arbitrary, and I don't believe that I can justify this as being a very good set. For one thing, I found that there were several "near misses." Second, since none of the ascenders accommodated the 120-50-40 gage, it was clearly too large to be meaningful. Perhaps I'll cut some more blocks out someday and try this again, but these will have to do for now.

Now for the results. A green dot indicates a fit with no problems, while a yellow dot indicates that the gage only fit in a particular ascender configuration not normally used for ascending (e.g., if the cam safety was not in the locked position). I used the symbol to emphasize a no-fit situation that some people might find surprising, just to show that I didn't omit a green dot by accident.

ID	Device	U.I.A.A.	60-20-20	80-30-30	100-30-30	110-35-35	120-50-40
Handled Eccentric Cam Ascenders
211	Advanced Base Camp
123	Altius, Version A
257	Altius, Version B
194, 195	Anthron AD-10 & AL-15, Version A
133, 134	Anthron VauDe AD-10 & AL-15, Version A
155, 154	Anthron VauDe AD-10 & AL-15, Version B
151	Camp Pilot
24	Clog Expedition, Version A
25	Clog Expedition, Version B
26	Clog Expedition, Version C
130	CMI Expedition
130	CMI Expedition, Dual Handle
27	CMI 5000
28	CMI 5002
29	CMI 5003
30	CMI 5004
114	CMI Large UltrAscender, Version A
31	CMI Large UltrAscender, Version A (Modified)
116	CMI Large UltrAscender, Version B
115	CMI Large UltrAscender, Version B (Modified)
216	CMI Large UltrAscender, Version C
246	CMI Large UltrAscender, Version D
32	CMI Small UltrAscender, Version A
34	CMI Small UltrAscender, Version A (Modified)
33	CMI Small UltrAscender, Version B
35	CMI Small UltrAscender, Version B (Modified)
220	Edelrid Elevator
256	Heightec-PMI Pulsar D40	(but only upside-down!)
199	Hugh Banner
145	International Safety Components
136	Jumar, Version A
36	Jumar, Version B
38	Jumar, Version C
118	Jumar, Version D
39	Jumar 78, Version A
40	Jumar 78, Version B
42	Jumar 78, Version C
187	Kirov
139	Kong-Bonaiti
22	Kong-Bonaiti Modular With Caver Handle
23	Kong-Bonaiti Modular With Climber Handle
23	Kong-Bonaiti Modular With Dual Handle			(one side)
249	Kong Procave
210	Kong Twin	(one side)		(one side)
165	Lucky Pern AD-10 & AL-15
43	Petzl Ascension, Version A
44	Petzl Ascension, Versions B1 & B2
46	Petzl Ascension, Versions C1
169	Petzl Ascension, Versions C2
127	Petzl Ascension, Version D
47	Petzl Pompe, Version A
241	Petzl Pompe, Version B
164	PMI Cat
157	PMI Puma
48	Roloff
122	Russian, Version A
123	Russian Interalp
49	Russian Uola
147	Single Rope Technique A1 EXP 6 Large Explorer
54	Single Rope Technique A1 Explorer
51	Single Rope Technique Caver, 8-11 mm
53	Single Rope Technique Caver, 8-15mm
50	Single Rope Technique Climber
178	Handled Ecc. Cam: Ural-Alp 10.32, Version A				(barely misses)
188	Handled Ecc. Cam: Ural-Alp 10.32, Version A				(barely misses)
Handled Type 1 Lever Cam Ascenders
219	Black Diamond nForce
55	Kong-Bonaiti, Version A
56	Kong-Bonaiti, Version B
58	Russian Copy of Kong-Bonaiti
Miscellaneous Ascenders
120	Ural Alp Handled
144	USHBA Handled

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©2008, Gary D. Storrick