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Centrolit
(Центролит)

Version B

Version C

Version C

Version B Version C Version D
Version B Version C Version D

Overview


History

These ascenders were made in Odessa at the Centrolit (Центролит) plant. The initiator was Igor Orobei, master of sports in mountaineering, who died on the Kashkatash glacier in the Caucasus. After Igor’s death, Tolya Kanarsky supervised the production of these ascenders. More than a thousand were made over an 80-year period. There were two major types: one oval, one rectangular.


Version A
(#3569)

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

Technical Details

I acquired this Centrolit (Центролит), Version A from Artyom Babin (Артём Бабин), 2025.

Cam faceThis Centrolit is 172 mm. tall, 79 mm. wide, 38 mm. thick, and weighs 24 g.

The Centrolit (Центролит), Version A is 172 mm. tall, 79 mm. wide, 38 mm. thick, and weighs 224 g. The rope channel is 15 mm. wide. The cam axle is centered 58 mm. from the inside of the rope channel. The cam radius, measured from the axle axis, increases from 46 to 61 mm. over an angle of 36°, giving a 24° cam angle. The tooth pattern is (4)^12.

The frame is an aluminum alloy chill casting covered with gray paint. The frame has a 14.5 mm. wide rope channel cast into one side. The handle opening is roughly a truncated oval. A channel in the inner top portion of the hand grip provides clearance for the cam and safety. The cam pivot is centered 58 mm. from the inside of the rope channel. A triangular hole above the cam provides an upper attachment point for auxiliary slings. The hand grip has a number of raised cast ribs on each side to provide a better grip.

The cam is an aluminum casting. The cam and cam spring are attached by a 6 mm. round head steel rivet. The cam radius increases from 46 to 61 mm. over an angle of 36°, giving a 24° cam angle. Conical cam teeth are aligned parallel to each other and perpendicular to the lower portion of the cam face. The tooth pattern is (4)^12. The cam is spring-loaded with the spring acting to close the cam. The cam safety is a cast aluminum.

The safety and safety spring are mounted on a 3 mm. rivet located 44 mm. below the cam pivot. The safety physically blocks the cam from opening far enough to allow the main rope to slip out of the rope channel. Rotating the cam safety towards the base of the ascender provides clearance for the cam to open completely. The safety is cast aluminum with a hook on the tip that engages a lip cast below the lower cam surface for holding the cam open.

There are no markings on this ascender.

Comments

This is a comfortable ascender, but the cam and safety are difficult to operate with one hand.

The cam is cast aluminum (and a soft alloy at that), so it will wear quickly.

The ascender is covered with red paint that was added after the ascender was assembles. All surfaces are covered, including the cam teeth and the springs. It is difficult to see how the coverage could have been achieved with spraying - indeed, it looks like the ascender was dipped.

There is no dedicated lower attachment hole, so the user must tie their slings directly through the handle opening. The shape and positioning of the reinforcing rib provides an area with sufficient cross-section, but the location is a bit inconvenient and is not optimal for some climbing systems. I much prefer the hole location on the rectangular versions as found on the early Jumars. I've discussed the issues in some detail on my Jumar 79-series page.


Version B
(#3448)

Front View: Closed Rear View: Closed
Front View: Closed Rear View: Closed
 
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 Centrolit, Version B from Vitaly Tomchyk in 2021.

Cam faceThis Centrolit is 171 mm. tall, 79 mm. wide, 35 mm. thick, and weighs 213 g.

The frame is an aluminum alloy chill casting covered with gray paint. The frame has a 17 mm. wide rope channel cast into one side. The handle opening is roughly a truncated oval. A channel in the inner top portion of the hand grip provides clearance for the cam and safety. The cam pivot is centered 58 mm. from the inside of the rope channel. A triangular hole above the cam provides an upper attachment point for auxiliary slings. The hand grip has a number of raised cast ribs on each side to provide a better grip.

The cam is an aluminum casting. The cam and cam spring are attached by a 6 mm. semi-tubular steel rivet. The cam radius increases from 43 to 58 mm. over an angle of 42°, giving a 23° cam angle. Conical cam teeth are aligned parallel to each other and perpendicular to the lower portion of the cam face. The tooth pattern is (2)(4)^12. The cam is spring-loaded with the spring acting to close the cam. The cam safety is a cast aluminum. The safety and safety spring are mounted on a 3 mm. pin located 47 mm. below the cam pivot. The safety physically blocks the cam from opening far enough to allow the main rope to slip out of the rope channel. Rotating the cam safety towards the base of the ascender provides clearance for the cam to open completely. The safety is cast aluminum with a hook on the tip that engages a lip cast below the lower cam surface for holding the cam open.

The only marking on the ascender is an ice ax cast in raised relief on the handle.

Comments

This version resembles the previous one but all parts, save possibly the springs, are new. The frame has the cast ice axe that is absent on the previous version. There are more ridges on the hand grip, the rope channel is wider and shaped differently, as are the minor reinforcing ribs. The cam is larger and has a different tooth pattern. The cam safety is shorter. The individual components were more carefully painted, and this was done prior to assembly. I believe that this is the later of the two versions.

This is a comfortable ascender, but the cam and safety are difficult to operate with one hand.

The cam is cast aluminum (and a soft alloy at that), so it will wear quickly.

There is no dedicated lower attachment hole, so the user must tie their slings directly through the handle opening. The shape and positioning of the reinforcing rib provides an area with sufficient cross-section, but the location is a bit inconvenient and is not optimal for some climbing systems. I much prefer the hole location on the rectangular versions as found on the early Jumars. I've discussed the issues in some detail on my Jumar 79-series page.


Version C
(#3422)

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

Technical Details

Cam faceI acquired my Centrolit, Version C from Artyom Babin (Артём Бабин) in 2021.

This version is 159 mm. tall, 72 mm. wide, 33 mm. thick, and weighs 183 g.

The frame is an aluminum alloy casting. The rope channel is 15 mm. wide. The frame has a 14 mm. wide rope channel cast into one side. The handle is roughly rectangular. A 26.6 by 18.1 mm. hole in the base of the handle provides access for the sling ropes. A triangular hole above the cam provides an upper attachment point for auxiliary slings.

The cam is an aluminum casting. The cam and cam spring are attached by a 5 mm. semi-tubular rivet. The rivet is centered 57 mm. from the inside of the rope channel. The cam radius increases from 45 to 59 mm. over an angle of 38°, giving a 22° cam angle. The cam teeth are aligned perpendicular to the cam face. The tooth pattern is (2.1)^5(2).

The cam safety and safety spring are mounted on a 5 mm. semi-tubular rivet located about a third of the way down the handle. The cam safety is a piece of cast aluminum. The cam safety physically blocks the cam from opening far enough to allow the main rope to slip out of the rope channel. Rotating the cam safety towards the base of the ascender provides clearance for the cam to open completely. A hook on the safety acts acts to hold the cam open, but it easily slips off. An extension on the rear side of the safety helps with operating the safety one-handed.

There are no markings on this ascender.

Comments

The frame casting quality is good. The cams appear rather crude, mainly because of the coarse rounded teeth, but the castings have no visible holidays.

The ascender is reasonably easy to operate one-handed with either hand.

When rigging this ascender, be sure to rig through the square hole on the bottom. Do not clip into the front strap, as it is not designed to support load.


Version D
(#3642)

Front View Rear View
Front View Rear View

Technical Details

Cam faceI acquired my Centrolit, Version C from Artyom Babin (Артём Бабин) in 2024.

This version is 159 mm. tall, 72 mm. wide, 32 mm. thick, and weighs 177 g.

The frame is an aluminum alloy casting. The rope channel is 15 mm. wide. The frame has a 14 mm. wide rope channel cast into one side. The handle is roughly rectangular. A 26.6 by 18.1 mm. hole in the base of the handle provides access for the sling ropes. A triangular hole above the cam provides an upper attachment point for auxiliary slings.

The cam is an aluminum casting. The cam and cam spring are attached by a 5 mm. semi-tubular rivet. The rivet is centered 53 mm. from the inside of the rope channel. The cam radius increases from 45 to 59 mm. over an angle of 38°, giving a 22° cam angle. The cam teeth are aligned perpendicular to the cam face. The tooth pattern is (2.1)^5(2).

The cam safety and safety spring are mounted on a 5 mm. semi-tubular rivet located about a third of the way down the handle. The cam safety is a piece of cast aluminum. The cam safety physically blocks the cam from opening far enough to allow the main rope to slip out of the rope channel. Rotating the cam safety towards the base of the ascender provides clearance for the cam to open completely. An extension on the rear side of the safety helps with operating the safety one-handed.

There are no markings on this ascender.

Comments

The safety on this version lacks the cam hold-open hook found on the previous version.


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