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Roller Cam, Version A
Roller Cam, Version B
Roller Cam, Version C
Connector Link
Pivot Arm
Truncated Cam
Wire Braid Keeper
Storrick Bogibbs
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| Roller Cam, Version A | Roller Cam, Version B | Roller Cam, Version C | Connector Link |
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| Pivot Arm | Truncated Cam | Wire Braid Keeper | Storrick Bogibbs |
This page is for major modifications. I do not include certain minor modifications like countersinking the axle hole in the cam or filing teeth off the cam here. I placed a Gibbs with the Rescue Technology Gibbs Replacement Spring Kit installed on its own page because the kit was a commercial product.
[ Top | Roller Cam v. A | Roller Cam v. B | Roller Cam v. C | Connector Link | Wire Braid Keeper | Truncated Cam | Bogibbs | Return to L.C. Ascenders ]
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| Front View | Rear View |
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| Front View: Open for Rigging | Rear View: Open for Rigging |
I acquired this modified Gibbs from Bob Elron around 1985.
This modified Gibbs is 104 mm. tall, 67 mm. wide, 57 mm. thick, and weighs 192 g.
The basic addition is a stainless steel arm with a tubular steel pivot attached. The cam pivot hole was drilled out to accept the tube, and the side of the cam was milled to provide clearance for the arm (I'm told that the hard coated cam made the machining more difficult). The cam is mounted on the tube, and held in place with a stainless steel washer and external retaining ring. The other end of the arm was riveted to the shell, loose enough to allow it to pivot.
I saw this modification at the PSC Pendleton County WV field house in the early 1980s, and took some photographs at that time. The photos didn't turn out. Around 1985 Bob Elron visited the Parks brothers and made this ascender under their direction.
This is a very nice modification of the Gibbs ascender. The result is an ascender that automatically aligns the cam hole with the shell hole, making rigging easier.
[ Top | Pivot Arm | Roller Cam v. B | Roller Cam v. C | Connector Link | Wire Braid Keeper | Truncated Cam | Bogibbs | Return to L.C. Ascenders ]
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| Front | Rear |
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| End | Open for Rigging |
I modified this Gibbs around 1977.
This modified Gibbs is 104 mm. tall, 63 mm. wide, 36 mm. thick, and weighs 198 g.
Many of the early rope-walking systems used a shoulder-mounted Gibbs instead of a chest roller. This has the advantage of providing an automatic rest position - just sit down - although having the rope run slightly off-center challenges the emotional stability of some cavers. One disadvantage of this is that the rope drags on the cam shell, creating friction and soon wearing through the shell. Kyle Isenhart and Delbert Province (The Nylon Highway #1) developed a simple solution: By making a "T-shaped cut in the shell and carefully straightening it, two "ears" are created that can be drilled to accept a bolt. A roller can be fashioned and mounted on the bolt.
My roller cam uses a 1/4-in stainless steel bolt and 5/16-in stainless steel tubing as the roller. I find that the roller usually doesn't turn, and recommend using a smaller bolt. On the other hand, there is no wear on my roller despite many miles of climbing.
The cam is modified in another way that is not visible in the photo. I took a large countersink bit and countersunk the pivot hole. This acts as a funnel to make it easier to insert the pin. It may void the manufacturer’s liability (do so only at your own risk), but the ascender is easier to rig onto the rope.
[ Top | Pivot Arm | Roller Cam v. A | Roller Cam v. C | Connector Link | Wire Braid Keeper | Truncated Cam | Bogibbs | Return to L.C. Ascenders ]
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| Front View | Rear View |
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| Spine View, Open for Rigging | End View, Open for Rigging | Side View, Open for Rigging |
I acquired this Gibbs modified Gibbs from Barbara Anne Am Ende at the 2012 NSS convention.
This modified Gibbs is 102 mm. tall, 63 mm. wide, 36 mm. thick, and weighs 192 g.
Barbara’s roller cam improved on mine in several ways. First, she started with a QR Pin Gibbs with a hard coated cam rather than a spring-wire Gibbs with an unfinished cam. Second, her Gibbs uses a 1/8 inch (3.2 mm) pin rather than a 1/4 inch (6.35 mm.) stainless steel bolt as the roller axle. Hers turns in some of the conditions where mine slips.
Like mine, her cam was countersunk to facilitate aligning the cam with the pin.
Barb allowed her pin to corrode to the point of becoming nonfunctional, so I replaced it before taking the pictures of the assembled ascender.
[ Top | Pivot Arm | Roller Cam v. A | Roller Cam v. B | Connector Link | Wire Braid Keeper | Truncated Cam | Bogibbs | Return to L.C. Ascenders ]
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| Front View | Rear View |
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| Open for Rigging |
I acquired this Roller Gibbs from Kelley Deem at the 2022 Old Timers Reunion.
This modified Gibbs is 103 mm. tall, 71 mm. wide, 65 mm. thick, and weighs 270 g. as shown in the photos.
This ascender was one of three that Kelley used in his Gibbs Ropewalker system; specifically, the shoulder Gibbs.. All three had the braided wire keeper that I discuss for the knee ascender, and this one also has the connector link modification that I discuss for the foot ascender. This ascender also has an upper roller to help reduce friction as suggested by Kyle Isenhart in The Nylon Highway #1. Kelley used a 9.3 mm. steel roller turning on a 3.5 mm. roll pin. The ends of the pin were flared to prevent them fro coming loose. His roller is not cylindrical; instead, it has a shallow U-shaped groove with a minor diameter of 8.9 mm.
Kelley told me that Delbert Province made this Roller Gibbs. Unlike Barb's and mine, this Roller Gibbs has only one roller. This follow's Kyle's Nylon Highway article, but most of us found the two-roller design was more efficient. The lower shell on Kelley's is worn to a sharp edge, something that a lower roller would prevent.
This Roller Gibbs places the roller lower on the shell than Kyle's design, Barb's roller, or my roller. This roller sticks rather far into the inside of the shell, keeping the rope from dragging on the upper edge of the shell. There is minimal wear in this area.
Like Barb, This Roller Gibbs used a small-diameter pin, and so his turns more consistently than mine does.
[ Top | Pivot Arm | Roller Cam v. A | Roller Cam v. B | Roller Cam v. C | Wire Braid Keeper | Truncated Cam | Bogibbs | Return to L.C. Ascenders ]
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| Front View | Rear View |
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| Open for Rigging |
I acquired this modified Gibbs from Kelley Deem at the 2022 Old Timers Reunion.
This modified Gibbs is 103 mm. tall, 63 mm. wide, 74 mm. thick, and weighs 252 g. as shown in the photos.
This ascender was one of three that Kelley used in his Gibbs Ropewalker system; specifically, the foot Gibbs. All three had the braided wire keeper that I discuss for the knee ascender.
This ascender has an aluminum bushing pressed into the cam eye. The bushing is drilled out to accept an MS22002-1 separable connector link. Nylon bushings on the link keep the cam centered on the link. Kelley's shoulder Gibbs used the same arrangement.
Separable Connector Links are readily available from parachute rigging suppliers and military surplus outlets. They were a popular (but by no means universal) way of connecting Gibbs Ascenders to harness components made of parachute webbing. This was particularly popular for the shoulder Gibbs; Kelley's use for the foot Gibbs was less common.
I used a similar arrangement in my ancient, soon-outdated article in The Nylon Highway #8, but did not use a press-fit bushing and relied solely on two shaped nylon bushings (I made my original bushings from a wooden sewing thread spool).
[ Top | Pivot Arm | Roller Cam v. A | Roller Cam v. B | Roller Cam v. C | Connector Link | Truncated Cam | Bogibbs | Return to L.C. Ascenders ]
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| Front View | Rear View |
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| Open for Rigging |
I acquired this modified Gibbs from Kelley Deem at the 2022 Old Timers Reunion.
This modified Gibbs is 103 mm. tall, 71 mm. wide, 37 mm. thick, and weighs 152 g.
This ascender was one of three that Kelley used in his Gibbs Ropewalker system; specifically, the knee Gibbs. All three had the braided wire keeper to replace the OEM cord keeper. The braided keeper was tied around the cam eye and then crimped to a wiring-type eye crimp provided on the side of the shell.
The OEM cord keepers frequently wore and broke, while the braided wire keepers appear to have survived quite well.
[ Top | Pivot Arm | Roller Cam v. A | Roller Cam v. B | Roller Cam v. C | Connector Link | Wire Braid Keeper | Bogibbs | Return to L.C. Ascenders ]
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| Front | Rear |
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| Open for Rigging |
I acquired this modified Gibbs from Bill Boehle at the 2008 Old Timers Reunion.
This modified Gibbs is 103 mm. tall, 64 mm. wide, 37 mm. thick, and weighs 144 g.
One side of the shell is stamped "GIBBS PROD."
The original owner cut the tip off the cam. The intent was probably to create a cam for racing. This saves weight (but only 8 grams), but means that the ascender cannot be used on very thin ropes. Of course, I wouldn't recommend using excessively thin ropes to begin with.
[ Top | Pivot Arm | Roller Cam v. A | Roller Cam v. B | Roller Cam v. C | Connector Link | Wire Braid Keeper | Truncated Cam | Return to L.C. Ascenders ]
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I made this modified Gibbs in 1983.
This ascender is 102 mm. tall, 60 mm. wide, 37 mm. thick, and weighs 286 g.
I made this ascender after seeing the Kantyú, long before I saw the Bogibbs.
I took a stainless steel Gibbs with a hard-coated cam, and had Ron Simmons make me a custom round-headed stainless steel axle bolt with an oversize nut. I cut the shell away on one side to allow rigging, and cut a notch on the back side so that the slings would clear while the rope was being rigged. The result is a Gibbs that is does not require disassembly for rigging: a definite improvement. I used a rather tight tolerance when I cut the shell, and I feel that more metal could be cut away to allow faster rigging, without increasing the risk of the ascender coming off rope accidentally.
I cut the two largest teeth off the cam, following the "lore" that originated with Don Davison’s article in The Nylon Highway #4. When used on 11 mm. or smaller ropes, these teeth do nothing but add drag.
This ascender is heavy. I could have saved weight in a number of ways, such as using an aluminum shell instead of stainless steel. The bolt and nut I used are larger and stronger than they need to be to keep the cam from torquing, and could also be lightened.
[ Top | Pivot Arm | Roller Cam v. A | Roller Cam v. B | Roller Cam v. C | Connector Link | Wire Braid Keeper | Truncated Cam | Bogibbs ]
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