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NTR

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

Technical Details

I acquired my NTR from Linko Chen in2015.

My NTR is 218 mm. tall, 62 mm. wide, and 32 mm. thick, and weighs 343 g.

The two side plates are made of 2.95 mm. aluminum. One side plate pivots to allow threading the rope. The lower ends of the side plates are bent to converge at the attachment point, which consists of a 16.1 mm. wide, 29.8 mm. high hole on the fixed plate and a slot on the other. Neither of the attachment points are beveled. The upper portion of the slot is covered by a plastic gate. The gate pivots on a steel rivet, and a spring set in a deep slot closes the gate. With the gate closed, the opening is only 17.3 mm high.

The lower bollard is part of an autostop assembly. It is a skeletonized plated stainless steel casting with internal reinforcing ribs and an integral cam. The lower surface of this bollard has an 8.5 mm. wide, 1.6 mm. deep U-shaped rope groove. The upper surface is flat. An aluminum handle is attached to the fixed side plate side of the lower bollard with a 5 mm. countersunk machine screw. The handle has a hard plastic cover for comfort. The lower bollard and handle assembly rotate on a bushing on the 8 mm. lower bolt. A concealed spring is strong enough to keep the handle in the disengaged position, but is weak enough to function only during storage. Friction from the main rope's passage tends to turn the lower bollard and force the toothed cylinder towards the upper bollard, thus locking the rope and ideally arresting the descent. The rappeller uses the handle to keep the autostop feature disengaged. A pin on the fixed-plate side of the autostop assembly limits the motion by hitting the fixed plate before the lower bollard cam nose contacts the upper bollard.

The upper bollard is turned aluminum with a milled slot to keep it from rotating on the fixed side plate. The bollard is bolted to the fixed side plate with an 8 mm. bolt and a shoulder nut. The pivoting side plate pivots on the lower bolt and has a slot to allow clearing the upper nut. The upper has a narrow 7.1 mm. wide, 4.4 mm. deep U-shaped rope groove. The upper bollard is cut away on its lower side to provide a flat surface to act as an anvil for the cam action of the autostop feature. A rounded 10 mm. steel cylinder is pressed into a hole in the lower surface of this bollard, and acts as a wear resisting bar.

The third (auxiliary) rod consists of a 12 mm. stainless rod turned and pressed into the fixed side plate, and then riveted. Before assembly, a 17 mm. wide surface is turned to 7.4 mm. where the rope runs.

The pivoting side plate has a decorative groove pressed into it. This groove has no structural significance.

The pivoting side plate is screened with a rigging icon and "Ø9-12mm," The rear side plate is screened with the "NTR", "CE1019," "EN341," and another rigging icon. The 8 mm. bolts are stamped "MIT."

Comments

The following bobbins are all variations of the same basic design:

Image Stop Bobbin Allowed Rope Notes
Good Makings Good Makings 10-12 mm.
  • The plating on the lower bollard is poor, and it was flaking off before it even arrived. I suggest stripping it off the running surfaces before use.
Climb Tech Climb Tech 9-12 mm. ---
Epic Peak Epic Peak 9-12 mm. ---
NTR NTR 9-12 mm. ---
Rock Empire Rock Empire 10-12 mm.
  • No decorative groove pressed into pivoting side plate.
Vento Vento 9-12 mm.
  • Painted bollards that can leave a mess on the rope.
  • No decorative groove pressed into pivoting side plate.

These bobbins appear to be made by the same Chinese OEM, so I find the difference in allowable rope sizes rather amusing and certainly unreal.

These descenders clearly "borrow" a lot of its design features from the Petzl Stop Bobbins. The shape of the frame, the details of the upper bollard, the shape of the lower bollard casting, and the shape of the plastic gate closely resemble those on later (and sometimes earlier) Petzl descenders.

There are a number of things about these bobbins which I dislike, although my opinions have mellowed a bit in the past couple years:

The gate design effectively reduces the risk of having the seat carabiner force the gate open. It also eliminates the corrosion problem that I've had with the metal gates on some of my early Petzl bobbins (the later Petzl bobbins also have plastic gates). Overall, I think the gate looks good, assuming that it holds up under the abuses inherent in serious caving, but the wire gate on the Russian Stop Bobbin, Version B is a worthy alternative.

Aside from the poor quality plating on the Good Makings lower bollard, these are fairly well made. Each gives a better visual first impression than the current Petzl Stop, but functionally, I don't see a significant advantage of either. If I compare these to the earliest Petzl Stops, I would give a small edge to the Petzls because of their 15% lighter weight and aluminum lower bollard.

The final concern is metallurgy - we simply do not have enough experience with Chinese-made climbing equipment to know how well we can trust it. I've seen a report of one failure posted on Facebook that I believe involves a Chinese-made Bobbin, but without knowing the details or being able to examine the failed bobbin, I cannot determine whether to blame the metal or the user - there are signs that the rappeller in this instance may have been clipped into only one of the side plates. In that case, any bobbin could fail. Having said that, I would like to see some independent testing.

Failed Bobbin Broken Side Plate
Uncopyrighted photos found on Facebook