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Roloff Ascenders
(a.k.a. Mother Lode Grotto Ascenders)

Version A Version B Version C
Version A Version B Version C
Modified Version A Modified Version B
Modified, Version A Modified, Version B

Overview


Version A
(#167)

Front Rear
Front Rear

Technical Details

I acquired this Roloff from Allen Padgett in 2003.

This Roloff is 176 mm. tall, 77 mm. wide, 38 mm. thick, and weighs 217 g.

The Roloff ascender uses a cast aluminum frame, cam, and cam safety, and are assembled with two machine screws, washers, and nuts . None of the parts are finished. The frame is patterned after the old Jumar frame, but the rope attachments have been changed to one 16 mm. hole below the handle and a second 16 mm. hole above the cam. The rope channel is 14 mm. wide.

The cam is cast aluminum. The cam radius increases from 42 to 58 mm. over an angle of 39°, giving a 24° cam angle. The teeth are conical, perpendicular to the cam face, and the tooth pattern is (4.3)^6. The cam and cam spring are mounted on a standard 3/16 inch machine screw secured with a washer and fluted nut. The screw is center punched so the nut won't accidentally come off.

The cam safety is cast in the Jumar gray series original pattern. The safety and safety spring are mounted on a 3/16 inch machine screw which is threaded directly into the frame.

The serial number (51) is stamped inside the frame.

Comments

Roloff Ascenders were developed as an inexpensive alternative to the "expensive" Jumar, which cost about $15.00 a pair at the time. They should be viewed as ambitious homemade devices. I find it amazing that anyone would actually attempt to duplicate a Jumar rather than buy one. A significant number appear to have been made; I'd be very interested in knowing how many. This one has serial number 51 stamped on the inside.

Roloff ascenders were made in the late 1960s, and by the time Prusiking was written (1973) they were no longer available. Since the Roloff has been out of production for decades, they are hard to find. The Jumar is a better device anyhow, so I don't recommend the Roloff for caving use. Its value is only as a museum piece, and it belongs in the hands of a collector.

Like the early Jumars, the Roloff is very easy to use. The cam can be opened easily with either hand. I find this Roloff occasionally slips, undoubtedly since the teeth on it are heavily worn.

The workmanship on this ascender is definitely not up to commercial standards, but remember, this was not a commercial ascender. The Roloff frame is not as nicely finished as the Jumar. Thrun quotes some anonymous test results indicating that the Roloff is weaker than the same vintage Jumar. I used to think that the lower sling attachment point is superior to the gray series Jumars that the design was based on, but over the years, my opinion has reversed. My opinion of the upper attachment has is not - I still prefer the one on the gray Jumars. The Jumar design is easier to grip from above.

The cam is definitely inferior to other eccentric cam ascender cams. The teeth are very poorly formed, uneven, dull, and wear quickly. The cam casting and subsequent machining is very crude. This Roloff ascender has hand filed cam teeth, but it probably does not have the original cam. I believe that Darrell made a new cam for this pair once the original teeth wore out. See Johnston, J. and D. Myrick, Homemade Ascender Cams, The Huntsville Grotto Newsletter, v. IX, # 6, June-July, 1968, pp. 81-85 for one way to do this.

The cam safety is also poorly finished. The cam is very loosely mounted on the cam pivot, and with slight sideways pressure the cam can hang up on the side of the rope channel. This keeps the cam from closing, and can ruin your day if it happens at an inopportune moment.

At the 1989 O.T.R., Bob Liebman first showed me a pair of "original" Roloff Cams with cast conical teeth. In 2009, Carl Kunath gave me a set of original Roloff cams, and Dick Mitchell gave me a pair of copies that he made by sand casting. Some of my later version Roloffs still have the original cams.

Original Roloff Cams Mitchell Sandcast Copies
Original Roloff Cams Mitchell Sand Cast Copies

Version B
(#2305)

Front Rear
Front Rear

Technical Details

I acquired my Roloff, Version B from Bill Liebman in 2017.

Version between A &  B is 176 mm. tall, 76 mm. wide, 37 mm. thick, and weighs 209 g. The rope channel is 14 mm. wide. The cam radius increases from 42 to 58 mm. over an angle of 39°, giving a 24° cam angle. The tooth pattern is (4.3)^6.

There are no markings on this pair of ascenders other than marks added by previous owners.

Comments

Bill Liebman got these ascenders from Ernie Coffman. Previous owners included Vance Smith (who stamped these with his initials "VMS") and Donald Bird (who engraved his name and NSS number). They are later than Version A since they do not have serial numbers, but the safety is screw-mounted as it is in Version A. These have original cams that have seen enough use to nearly wear away the top row of teeth, but the remaining teeth are in fairly good condition.


Version C
(#2040, 2181)

Front Rear
Front Rear

Technical Details

I acquired my Roloff, Version C at the NSS Auction in 2016. I acquired another pair in 2017 as part of Bob Thrun's collection.

Version C is 175 mm. tall, 78 mm. wide, and 39 mm. thick, and weighs 237 g.

On Version C, the safety and safety spring are mounted on a 3/16 inch (4.8 mm.) pin pressed into the frame and filed smooth on both ends.

There are no markings on this pair of ascenders.

Comments

After many years, I finally was able to obtain a good set of unmodified original Roloff ascenders at the NSS Auction in 2016. These were made in 1968 or 1969, and are believed by the original owner to have been the last pair assembled, since they were specially assembled for him from the last remaining parts.


Modified, Version A
(#2179)

Front Rear
Front Rear

Technical Details

I acquired this pair of ascenders (serial number 50) in 2017 as part of Bob Thrun's collection. He bought these from Louise Hose at an NSS auction.

This pair is modified. In the current condition, each is 176 mm. tall, 77 mm. wide, 38 mm. thick, and weighs 253 g. The rope channel is 14 mm. wide.

The original ascender cams were replaced by early Jumar cams. The cam radius increases from 42 to 60 mm. over an angle of 41°, giving a 27° cam angle. The tooth pattern is (4.5)^5(4.3)^4.

The serial number (50) is stamped inside the frame.

Comments

The Roloff cams were made of aluminum. These wore quickly, and so a popular modification was to replace the worn cams with early Jumar cams made from stainless steel. These were readily available before tort liability lawyers ruined the world.


Modified, Version B
(#48)

Front Rear
Front Rear

Technical Details

I acquired this pair of ascenders (serial number 17) from Darrell Tomer in 1985.

This pair is heavily modified. In the current condition, each is 175 mm. tall, 77 mm. wide, 39 mm. thick, and weighs 208 g. The rope channel is 15 mm. wide. The cam radius increases from 41 to 58 mm. over an angle of 39°, giving a 26° cam angle. The tooth pattern is (4.3)^5.

The holes in the rope channel and the handle portion of the frame seen in the photographs are later additions due to Darrell's tinkering, as is the steel sheet metal wear plate added inside the channel. One of the cam springs is very strong, the second is very weak. The former is original and the latter is a replacement. The cam and cam spring are mounted on a standard 3/16 inch machine screw with a washer and fluted nut. The screw is center punched so the nut won't accidentally come off. The cam teeth are hand filed in a (4.3)^5 pattern (see Johnston, J. and D. Myrick, Homemade Ascender Cams, The Huntsville Grotto Newsletter, v. IX, # 6, June-July, 1968, pp. 81-85 for one way to do this). The safety and safety spring are mounted on a 3/16 inch machine screw which was originally threaded directly into the frame. The threads are stripped out on the left hand ascender, so a longer screw and hex nut have been substituted.

Comments

Darrell Tomer loved to modify equipment, and his two Roloff ascenders were recipients of substantial modification. When I first saw these in 1978, they had PVC pipes bolted to them to make long extension handles, and the cams had been replaced by cams from the original gray Jumars. Fortunately, Darrell saved all the parts he removed, so I was able to restore them to something resembling their original condition.