|Front: Open for Rigging||Rear: Open for Rigging||Bottom|
I acquired my SOB from wojoaonline in 2021.
The SOB is 73 mm. tall, 77 mm. wide, 24 mm. thick, and weighs 90 g.
The SOB consists of a pivoting lever and two posts mounted between two side plates. One side plate is stationary, while the other pivots on the lever axle so that it may be opened to admit the rope. The lever is spring-loaded so that the tag side closes against a smooth, slightly convex anvil. The anvil is attached to the rear face plate with two stainless steel pins, one of which is extended to engage a notch in the front face plate.
The front is printed with "SOB," an aillustration of the ascender on rope, "CE", "EN567," "GA404-2004," "Max 100kN," and "Ø8-13mm."
The SOB is one of the following closely-related rocker-arm ascenders:
These are small, reliable, but inefficient ascenders. There is a significant lost motion with each step as the entire ascender rotates under load. I wouldn't choose one of these for a long climb, but their small size might make them attractive for short, remote drops.
To rig these ascenders, open the swinging plate and bring the standing rope down between the lever and the anvil. Close the swinging side gate, and insert a carabiner through the holes. When load is applied to the carabiner, the rope exerts a counter-clockwise torque on the lever, and the left side of the lever squeezes the rope against the anvil. Lifting the carabiner will allow the ascender to slide up the rope, provided there is enough rope weight below.
The Russian Turin Slip-Stop Basic and Vento each have a guide pin that the others lack. I don't notice the pin making much difference in how an ascender performs, but its weight is negligible so I see no harm in having it.
This type of device was invented by Soviet climber Yuri Gorenchuk (Юрий Горенчук). The C.A.M.P. Lift was the first non-Russian version, and it had teeth on the outside of the anvil
(see the Camp Lift page for the reason why) .
The teeth serve no function for the ascender whatsoever, but they were faithfully reproduced on all the Chinese copies.