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Kong-Bonaiti Modular

Caver Handle Climber Handle Dual Handle
Caver Handle Climber Handle Dual Handle

Overview


The 1990s-vintage Kong-Bonaiti Modular system is among my favorites when it comes to flexible design. It is rarely seen used (I've been desperately looking for decades), so I suppose that it never became popular; certainly, it never achieved the popularity of the monolithic Petzl ascenders. Preferring the ruggedness of milled-frame ascenders and the ergonomics of Jumar 79s myself, I never used my Modular system much, but I like it nonetheless.

The system started with a relatively normal hand ascender. I have two versions of these, differing in the length of the cam safety tabs. Alone, they are nothing special, functioning much like many similar ascenders: not poor, not great, just normal. What makes them special are the two keyholes and the screw hole in the shell. These allow attaching other goodies.

These goodies start with handles, which came left- and -right-handed versions and in two sizes. The larger handle, as it was officially known, was generally referred to as the climber’s handle. It had U.I.A.A. approval. The smaller handle was known as the caver handle, and it did not meet U.I.A.A. standards.

Does this mean it was unsafe? Don't be silly. The U.I.A.A. handled ascender standard had a criterion for the size of the handle opening (a 95 mm. long block with a 15 mm. diameter radius at one end and a 15 mm. radius at the other) had to fit through the handle opening. The opening on the smaller handle was, well, too small.

The handles had rivets that mated with the keyhole slots in the ascender shell, and a screw through the shell held the handle in place. The user could change between a handleless ascender, a small-handled ascender, or a large-handled ascender at a whim. – but the magic continued. The small handle could also be attached a large handle attached to an ascender shell, making a twin-handled ascender suitable for arborists, froggers, inchwormers, and for chin-up practice.

The modular instruction sheets don't show it, but the system continued: the modular ascender could be attached to the block roll to make a hauling pulley. I have two modular versions, a 1996 version with a phosphorescent plastic gate that attaches to a right-handed modular ascender, and a 1999 version with a stamped steel gate that attaches to a left-handed modular ascender.

Alas, Kong abandoned the whole idea of trusting people to install a screw properly, and started riveting the parts together. This destroyed the entire modular concept (although Kong still called these modular ascenders for a while). Eventually they realized that making an ascender shell as two parts riveted together was inefficient, and they moved to one-piece designs similar to everyone else. It is a real shame, for the modular idea, perhaps a bit unnecessary or impractical, was still rather cool.


Modular Ascender

Kong-Bonaiti made a modular ascender system centered around their modular ascender. This is a handleless eccentric cam ascender with slots and holes so that accessories can be attached. In addition to the handles shown here, the Block Roll attachment turns the ascender into a hauling pulley.

Instructions Instructions

Caver Handle
(#22)

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 obtained a pair of caver handles from Inner Mountain Outfitters in 1992. I later acquired two left-handed ascenders with a caver handles from Geoffrey Storey in 2012.

The caver handle is made from 3.6 mm. anodized aluminum alloy. There are no reinforcing ribs. The handle has an 84 mm by 46 mm., irregular shaped hand opening. It has two rivets at the top that mate with the keyhole slots in the modular ascender. A stainless steel insert near the top of the handle has a threaded hole aligns with the countersunk hole in the modular ascender, and a countersunk Allen-head screw holds the handle in place. A hole on the strap and a rivet allow attaching the caver handle to the climber handle. A 13.6 mm. hole at the base forms the main sling attachment point. This hole is not beveled.

A white, fluorescent, plastic hand grip is molded to the sheet metal frame. The handgrip has four shallow, closely spaced finger grooves.

The front side of the hand grip has "BONAITI - KONG - ITALY" in raised letters.

Comments

The small handle is designed for caving use. One of my plastic handles broke in storage, showing that the fluorescent plastic deteriorates over time. Alex Sproul at Inner Mountain Outfitters supplied a replacement, but I have that one installed on the dual handle version.

Instructions Instructions
Instructions

Climber Handle
(#23)

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 obtained a pair of climber handles from Inner Mountain Outfitters in 1992. I later acquired a pair of ascenders with climber handles from Curtis Gray in 2007, another from Chris Christensen in 2009, a left-handed from Jack R Reynolds in 2019, and a well-used right-handed from Avi Basri in 2021.

The climber handle is made from 3.6 mm. anodized aluminum alloy. There are no reinforcing ribs. The handle has a 99 mm by 48 mm. oval hand opening. It has two rivets at the top that mate with the keyhole slots in the modular ascender. A stainless steel insert near the top of the handle has a threaded hole aligns with the countersunk hole in the modular ascender, and a countersunk Allen-head screw holds the handle in place. Two holes on the strap (the top one countersunk) allow attaching the caver handle. A 13.6 mm. hole at the base forms the main sling attachment point. This hole is not beveled. handle.

A white, fluorescent, plastic hand grip is molded to the sheet metal frame. The handgrip has four shallow, closely spaced finger grooves.

The front side of the hand grip has "BONAITI - KONG - ITALY" in raised letters. The frame is stamped "UIAA."

Comments

The large handle is designed for mountaineering use. It provides more clearance for mittened hands.

Instructions Instructions
Instructions

Dual Handle
(#23)

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 Kong-Bonaiti modular, dual handle from Inner Mountain Outfitters in 1993.

The Kong-Bonaiti modular, dual handle is 208 mm. tall, 159 mm. wide, 37 mm. thick, and weighs 321 g. The rope channel is 15 mm. wide. The cam radius increases from 38 to 58 mm. over an angle of 42°, giving a 30° cam angle. The tooth pattern is (3)(4.H)^2(3.H)^2(2.2.1).

The modular ascender is stamped with "KONG-BONAITI-ITALY" and "UIAA." The climber handle is stamped "UIAA." One side of each handle has "KONG-BONAITI-ITALY" molded into it, and the other side has the molded word "PHOSPHORESCENT."

Comments

The indecisive and those with special situations can bolt a climber handle to the modular ascender, then attach a caver handle to form a double-handled ascender. In this configuration, the lower attachment holes in the Caver and Climber handles align to form a single attachment hole.

Instructions Instructions
Instructions