Front	Rear

Technical Details

I acquired my Harken Ninja from Rock N Rescue through Amazon.com in 2021.

The Ninja consists of a stamped, anodized aluminum shell, two cam assemblies, and a set of straps and buckles. It is 73 mm. tall, 80 mm. wide, 27 mm. thick, and weighs 177 g., including the harness. The straps are sewn to the harness so I was not able to get a bare weight.

There are two cast and plated steel cams. The cam radius increases from 37 to 55 mm. over an angle of 67°, giving a 17° cam angle. Each cam is spring-loaded and has a (Z)^8 tooth pattern on a concave cam face. The cam springs are extremely weak but sufficient. There are no cam safeties and no method for locking the cams open.

The front of each cam channel is printed with "ninja." The left channel spine is printed with the Harken Industrial logo. The right channel spine is printed with an up-pointing arrow, a book-with-an-"i" icon, "Ø8-13mm," and "Weight limit: Max 150kg." The rear of mine is printed with "S/N 2021181-0122."

Comments

The Ninja is designed for ropes ranging from 8 mm. to 13 mm. It is identical to the Notch Equipment Jet Step.

A complaint that applies to most foot ascenders is that they come off rope too easily. The Ninja seems far less likely to have this problem than others. Although it is not completely symmetric, the Ninja seems to work equally well on either foot, with the main difference that most people favor one foot over the other, just like they tend to be right- or left-handed.

The harness design and size of the ascender help hold the Ninja in position better than the many other foot ascenders.

The dual cam takes some getting used to. One advantage is that it allows for much weaker cam springs, and so the Ninja does not tend to lift the rope as much as normal foot ascenders do. The Z-shaped teeth also help reduce the tendency to lift the rope.

Foot ascenders such as this don't fit into the climbing systems that I commonly use, although I have met froggers that seem to like them (they also like the frog).