Mad Rock Gemini

Mad Rock

Name:Mad Rock Gemini
Category:screw lock
Locking Type:manual
Unlock Style:gate stopped
Sleeve Rotation:1170° (unlocked) | 1485° (maximum)
Nose Guard:none
Gate Shield:full
Anti Crossload:exterior solid gate
Weight:70 g
Dimensions:Length: 130 mm
Width: 60 mm
Depth (basket end): 11.02 mm
Gate Opening: 15 mm
Strength Ratings:Major Axis: 23 kN | Minor Axis: 7 kN | Gate Open: 7 kN
Other Markings:Forged: MAD ROCK | ratings CE2008 Ⓗ
Laser: (image of gemini in use) R C 1 Tested Pat. Pend.
MSRP:$20.95 (2022)
Collection Criteria:★ Mechanically Interesting
★ Manufacturing, Engineering, or Design
Summary:unique twin compartment carabiner design with directionally interlocked gates
Description & Commentary:

The gemini is yet another belay-oriented carabiner (conjoined carabiners) but takes a wild approach - attaching two carabiners together! It can also be though of as just a carabiner with a large, externally gated eye. I could see how this permits a greater range of items which will fit in the gated eye end, but I would be curious to know if there's any specific application which cannot be met with a simpler system like the BD GridLock or one of the many carabiners with internal wire gate eyes. (If you have an example, please contact me!)

Other anti-crossload carabiners seem better suited to general uses, whereas the Gemini seems less flexible in applications. The small gate opening and relatively small bend radius (for a belay carabiner) means it is not compatible with some mechanical belay devices. As with all carabiners, care must be taken to avoid leveraging it over an edge or other fulcrum. The long length of the Gemini would make it more likely to be compromised in this way.

The gate interlock is clever - the upper (screwlock) gate opens independent of the lower gate, but opening the lower gate will also open the upper gate. If the upper gate is locked, it prevents the lower gate from opening. I am curious to know the face strength of each of these gates.

Relevant Patent:US20180056134A1