Collection Home
|
|
 |
 |
 |
| Front | Rear | Left Side | Right Side |
 |
 |
| Front: Open for Rigging | Rear: Open for Rigging |
I acquired my Z&W from Duoqiao Technology (sporting_mall) in 2019.
My Z&W is 228 mm. tall, 58 mm. wide, 30 mm. thick, and weighs 376 g.
This descender consists of a fixed plate in the rear and a pivoting plate in the front with two bollards and an autostop assembly consisting of a cam, handle, and connecting arm. The plates are each 2.8 mm. thick. The pivoting plate is stamped with a decorative line running down the left side and around the base off the hook, and then back to join itself near the top of the safety.
Starting at the top of the fixed plate, the autostop cam is mounted on a shoulder rivet near the top. The head and shoulder of this rivet fit into a notch in the pivoting plate.
The upper bollard sits 41 mm. lower, where it is riveted through its center. This bollard is made from aluminum alloy. It is 44.7 mm. in diameter and 16.7 mm. thick. A 2.8 mm deep milled channel in the bollard fits around the fixed plate to prevent rotation. There is also a milled recess to provide clearance for the autostop assembly connecting arm. The rope groove is U-shaped, 9.2 mm. wide, and 5.5 mm. deep. The pivoting plate has a second notch that engages a shoulder area on the mounting rivet. These notches provide support to keep the pivoting side plate from bending open during descent.
The lower bollard is 42 mm. in diameter, 13.2 mm. thick, and made from stainless steel. Its form is that of a circle truncated by two chords. The lower bollard rotates on a shoulder rivet attached to to the fixed side plate about 56 mm. below the upper bollard. This bollard has a 3.5 mm. deep, 9.2 mm wide V-shaped groove on its circular peripheral arcs. There is a a washer separating the lower bollard from the pivoting side plate.
A handle assembly mounted on the outside of the fixed side plate rotates on the same rivet as the lower bollard. The friction from the passage of the main rope causes the lower bollard to rotate, rotating the handle and pulling the connecting rod down. This pulls one end of the the autostop cam against the rope above the upper bollard, thus slowing the descent. The handle is used to keep the cam disengaged during normal descent, but pulling the handle too far brings the other end of the autostop cam against the rope, again slowing the descent.
A split pin pressed into a hole in the pivoting side plate engages an arc-shaped groove in the lower bollard. This forces the bollard to turn when the side plate is opened fully. This, in turn, rotates the handle, pulling the connecting arm down, and forcing the cam against the rope.
The attachment point is a 16.3 by 27.6 mm. oval hole near the bottom of the fixed plate. The hole is oriented vertically. The pivoting plate has a hook with a spring-loaded plastic safety.
The pivoting plate is printed with "Z&W," a rigging illustration, "ROPEØ10-13mm," "max.150kg," "max.100m," and "CE 1019 EN341."
The Z&W is one of the following group of similar double-stop bobbins:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
These descenders clearly "borrow" the autostop concept from Kong and in particular from the King Indy.
These each have a lever at the top that provides both a release-stop and a panic-stop feature. Unlike the Petzl Stop design, the stop design developed by Kong-Bonaiti and copied on these ascenders has never worked well for me. It simply does not provide enough stopping force to hold me in position, let alone arrest a rapid descent. I've been able to complete rappels on these bobbins without touching the handle, a situation that should not allow me to move.
As for the panic stop feature, squeezing the handle hard enough will slow the descent. Depending on the rope in use, this may occur whn one is tring to hold the handle in the middle position for a normal descent. I've never fully understood why people promote panicing as desirable behavior, and I find double-acting levers designed to address this questionable behavior maddening. You may like them, but if this is because you like to panic, I suggest you fullly dispense with that behaviour first and then move on to single-acting devices.
This autostop design adds unnecessary length and width to the descender. It is too complicated for my taste, with too many pivoting joints that may fail. I cannot recommend this type of stop (let alone double-stop) feature over the Petzl Stop design.
The Asol, Ito-Rocky, NewDoar, and Z&W are essentially identical except for their colors and markings. They appear to be made by the same Chinese OEM, so I find the difference in allowable rope sizes rather amusing and certainly unreal. I suspect that the differences are due to different descenders being tested at different times, and the rope sizes printed reflect the rope sizes used during the corresponding tests.
These bobbins introduce an "improvement" where opening the side plate forces the cam against the rope. Not only does this not work for the reasons just discussed, but it is not even desirable. Cavers routinely open bobbins to pass rebelays, and having a "feature" that prevents inserting or removing the rope at that time is a nuisance at best and a hazard at worst.
The lower bollard is steel and will wear well, but it does not provide the same heat dissipation that an aluminum bollard would. The upper bollard is aluminum. Upper bollards of the same material last longer than the lower ones, but they still wear out, and since these are riveted in place, it is difficult for the user to replace a worn bollard unless (s)he has access to metalworking machinery.
The gate design copies the design of the later Petzl bobbins. This gate design effectively reduces the risk of having the seat carabiner force the gate open. It also eliminates the corrosion problem that I have had with the metal gates on some of my early Petzl bobbins. I think this gate design works well, but the wire gate on the Russian Stop Bobbin, Version B is a worthy alternative.
The nice gate does not offset the deficiencies in the autostop design, and so I cannot recommend these descenders.
.For far more content, use a larger monitor and a full-width window.
Hundreds of cell phone users complained and asked me to for a simpler, mobile friendly site. In particular, they wanted me to limit each page to a small number of pictures and minimize my use of text. This new site provides what they asked for.
