Front View	Rear View	Side View

Front View: Open for Rigging	Rear View: Open for Rigging

Technical Details

I acquired my SUT from Kangjin Liao in 2017.

My SUT is 232 mm. tall, 66 mm. wide, 31 mm. thick, and weighs 474 g.

The upper bollard is bolted through its center to the fixed side plate, with a roll pin provided to prevent rotation. The aluminum upper bollard is 45 mm. in diameter and 13 mm. thick, with a 9.7 mm. wide, rounded V-shaped groove turned to give an inner diameter of 36 mm. The lower bollard is 50 mm. in diameter, with a shallow U-shaped groove giving a 45 mm. inner diameter. Two cuts reduce the lower bollard to a wedge shape. The upper cut is 40 mm. long, the lower 34 mm., and the angle between the cuts is about 25 degrees. The steel lower bollard rotates on a custom axle bolt riveted to the fixed side plate. A handle assembly mounted on the outside of the fixed side plate rotates on the shoulder nut attached to this bolt. A pin extending from the lower bollard engages a hole in the handle, causing the two to move together. The handle grip is molded black plastic.

A rivet connects the handle to a connecting arm. The other end of the connecting arm is riveted to the autostop cam. 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 the autostop cam against the rope above the upper bollard, thus ideally arresting the descent. The handle is used to keep the cam disengaged during normal descent. The autostop cam works in both directions, to stop if the rappeller lets go or squeezes the handle too tightly.

The attachment point is a 13.4 by 26.9 mm. vertical oval hole near the bottom of the two side plates. The hole on the pivoting side plate is cut away to form a hook, and a spring-loaded stamped gate is fixed to the side plate.

The front of the SUT is printed with a hollow up-pointing arrow, "SUT," an anchor-and-"Z" icon, a rigging illustration, a down-pointing arrow, "Max:100m," "30-150kg," "EN341," and "use rope ø9mm - 12mm."

Comments

The SUT is one of the following group of similar double-stop bobbins:

Image Device Upper Bollard Lower Bollard Connecting Link Safety Lever Hand Grip Hook Safety Certification Allowed Rope Size Weight Limit(s) Max Drop Kong Indy Aluminum Aluminum Flat Bar Aluminum Extrusion Ribbed Plastic Stamped Stainless Steel EN341/A, prEN12841/C 10-11 mm. (EN341/A) 10-13 mm. (EN12841/C) Max. 1.5 kN. 100 m. Camnal Down Aluminum Aluminum Flat Bar Aluminum Extrusion Ribbed Plastic Stamped Stainless Steel EN341 10-12 mm. Max. 150 kg. 100 m. SOB Aluminum Aluminum Flat Bar Aluminum Extrusion Ribbed Plastic Stamped Stainless Steel EN341 10-12 mm. Max. 150 kg. 100 m. Chinese Aluminum Aluminum Flat Bar Aluminum Extrusion Ribbed Plastic Stamped Stainless Steel EN341 10-13 mm. Max. 150 kg. 100 m. Vento Aluminum Aluminum Round Bar Aluminum Extrusion Plastic /w Finger Grooves Stamped Stainless Steel EAC 10-13 mm. Max. 150 kg. 100 m. S.E.Peak SE-218 Aluminum Forged Aluminum Flat Bar Forged Aluminum Smooth Stamped Stainless Steel EN341/A EN12841/C 10-13 mm. 30-150 kg 200 m. SUT Aluminum Steel Flat Bar Aluminum Extrusion Ribbed Plastic Stamped Stainless Steel EN341 9-12 mm. 30-150 kg 100 m. Ito-Rocky Aluminum Forged Steel Flat Bar Aluminum Extrusion Ribbed Plastic Plastic EN341 9-12 mm. 30-150 kg 100 m. NewDoar Aluminum Forged Steel Flat Bar Aluminum Extrusion Ribbed Plastic Plastic EN341 9-12 mm. 30-150 kg 100 m. Asol Aluminum Forged Steel Flat Bar Aluminum Extrusion Ribbed Plastic Plastic EN341 10-13 mm. Max. 150 kg. 100 m. Z&W Aluminum Forged Steel Flat Bar Aluminum Extrusion Ribbed Plastic Plastic EN341 10-13 mm. Max. 150 kg. 100 m.

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 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 the one on the SUT is riveted in place, it is difficult for the user to replace it unless (s)he has access to metalworking machinery.