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Jumar 79-series

Version A Version B Version C Version D
Version A Version B Version C Version D
 
Version E WAG Fritschi Modified Version D
Version E WAG Fritschi Modified Version D

Overview


Version A
(#39, 297, 2067)

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

Technical Details

I acquired one pair of ascenders from Speleoshoppe in 1979, and a second pair from John Friedman on eBay in 2009. I acquired another pair in 2017 as part of Bob Thrun's collection.

In 1979 the Jumar 79 became available. The most distinctive difference is the color. The old light gray was replaced by a new bright yellow. In addition to the color change, numerous other changes were made to the rest of the ascender.

The frame had numerous modifications, but the general Jumar pattern remains. The most important change is the use of a new, tougher alloy. This alloy does not appear subject to brittle fracture like the gray frames were. Most of the frame has been made heavier. The rope channel is taller, and a third reinforcing rib is cast into the back of the rope channel and the back of the frame. The front strap and the strap over the upper attachment hole were thickened. The lower portion of the ascender was completely redesigned. The sling attachment hole is a 16 mm. circular hole oriented horizontally. The frame is 10.3 mm. thick at this point, giving a very good surface for attaching slings.

The cam was also redesigned. A reinforcing bar was added to the inside of the cam. The cam teeth were enlarged, and the tooth pattern was changed to (4.5)^3(4.3)^3. The entire cam, including the teeth, is very well made.

The plastic cam safety is also new. Instead of the old "straight" design, the new design has a 135° elbow. The safety to pivots at a similar location as the old safety, so the effectiveness as a safety is unchanged. The elbow allows half of the safety to sit inside the handle when not activated, so it does not interfere as easily with one's hand. A "beak" on the end of the cam safety can hold the cam in the half open position if desired. Similarly, a tab at the elbow can hold the cam 3/4 open (the rope can slip out here), and the flat between the elbow and pivot provides a full open hold.

Version A is 179 mm. tall, 77 mm. wide, 36 mm. thick, and weighs 263 g.

Comments

This ascender was developed in response to reports of "gray" Jumar failures such as the ones mentioned above. The new design is substantially heavier and more rugged than the older models. When I visited Walter Marti, he let me pound on a Jumar with a sledge hammer. I gave it a number of hard blows, blows that were far worse than one would ever reasonably expect to deliver on even the hardest caving trip. The Jumar was severely mangled and distorted after I finished, but it did not crack.

The larger, more widely spaced cam teeth are less sensitive to mud than the old ones were. The "Gray" series Jumars had a partially deserved reputation for poor performance in muddy conditions. The "Yellow" series Jumars do not seem to have this stigma attached to them. I find that the "Yellow" Jumars perform better in mud than the "Gray," but I suspect that the bad reputation of the old Jumars was partly due to their being compared to knots rather than other ascenders; after all, one can virtually always get knots to work.

The elbow in the safety makes the Jumar slightly harder to use one-handed than the older gray models, but the difference probably isn't worth worrying about. The same motion can be used as on the older versions. On the other hand, the new design is much harder to open accidentally. This is a persuasive argument in favor of the elbow design. I don't like the beak on the safety, for the same reasons I don't like the teeth on the C.M.I. UltrAscender safety. A penknife solves the problem on this model, the improved safety on the later Jumars eliminates it completely. A few of the earlier Jumar 79s had a defective cam safety spring (Montgomery, N. and D. Mrozkowski, A Note on the Jumar, N.S.S. News, v. 39, # 1, Jan., 1981, p. 20; Montgomery, N. and D. Mrozkowski, The New Jumar, Caving International Magazine, #10, Jan., 1981, pp. 42-46). One end of the spring was too short, so the spring tended to pull through and unwind, losing its ability to function in the process. These were replaced under warranty by a newer, 1.5 mm. longer spring which cured the problem.

When the Jumar 79 came out, I bought a pair. Version B came out very shortly thereafter, and I bought a second pair. I took three of the ascenders and a Gossett Box and made a climbing system based on the Cuddington 3-phase. Since then I have done virtually all of my vertical work with this system, or the Texas System obtained by leaving one Jumar and the box in the truck. Because Jumars were my normal caving ascender for many years, I have more experience with them than with almost any other devices in my collection. I have been happy with their performance under a wide range of caving conditions, including clean ropes, dust, mud, snow, ice, and waterfalls. I've used them on ropes ranging from 7 mm. to 13.5 mm. including Goldline, Samson, BlueWater II and III, PMI of various flavors, Mammut, Edelrid, and even an oil soaked piece of manila hanging from an 1898 vintage oil derrick. In every case, they have worked, although climbing an iced Edelrid rope took a bit of special effort. In the 1990s, I retired the Version A ascenders, but I haven't given up on Jumars - I'm using Version E now. The Jumar 79 series ascenders remain my favorite for many applications. Many other ascenders are smaller and lighter, but in many cases I'll sacrifice space and weight in favor of versatility and ease of use. The Jumar is strong, well made, reliable, comfortable, easy to use, easy on ropes, versatile, rugged, fast, and just plain feels right. Other ascenders have many of these properties, but the Jumar puts them together in a package that I am very happy with.


Version B
(#40)

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

Version B CamI acquired this pair of ascenders from Speleoshoppe in 1979.

The cam safety was modified in late 1979. The new design moved the beak from the tip of the safety to the elbow. The beak is shielded by two breakaway tabs. If the tabs are not removed, the beak is nonfunctional and the only cam hold open position is full open. If the breakaway tabs are removed, the beak is exposed and can be used to hold the cam half open. The full hold open feature remains functional.

Version B is 179 mm. tall, 78 mm. wide, 37 mm. thick, and weighs 273 g.

Comments

This change eliminates my one complaint with the original Version A. Naturally, I leave the tabs in place.


Version C
(#41)

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

Technical Details

I received this left-handed ascender as a gift during my visit with Walter Marti in 1982.

Version D is 179 mm. tall, 78 mm. wide, 37 mm. thick, and weighs 271 g. It is identical to Version B except two holes have been drilled near the top and bottom of the rope channel, and a 4 mm. stainless steel is press fit into each hole. The pins are partially exposed on the inside of the rope channel.

Comments

This ascender was a prototype developed for use on an Austrian caving expedition. The Austrians used it and returned it to to Walter, who passed it on to me.

The pins are added as wear resistors. Europeans usually use the Frog System for caving, and the chest ascender in the Frog tends to wear rapidly since it is moved up the rope while the caver's weight is pulling the ascender rope channel back against the rope. This causes far more ascender wear than most U.S. climbing systems. After 10 years of use, during which I wore out a dozen brake bars on my racks and several figure 8s, I did not even finish wearing through the paint on the inside of the rope channel of my Version A Jumars. The reason is twofold: using clean ropes whenever possible, and an ascending system where ascenders are not raised while they are loaded.

The steel pins will have to wear away before the aluminum rope channel can wear significantly. These pins are an excellent example of a very simple design modification which has no real disadvantages and significantly improves the overall ascender.

My Version C is a left-handed ascender. If you have a right-handed Version C (with a (4.5)^3(4.3)^3 tooth-pattern cam) that you are willing to part with, please email me.

Version D
(#265, 270, 285, 1532)

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

Version D CamI acquired my Jumar 79, Version Ds used on eBay in 2009 as follows: a left from J. Matzke in 2009, a pair from Charles Denning in 2009, another left from Henderson L. Holman IV in 2009, a pair from Jeff DeFreest in 2010. I acquired another pair from Charlotte Phillips in 2012 but modified that pair.

Version D is 179 mm. tall, 78 mm. wide, 37 mm. thick, and weighs 272 g.

The frame on Version D is identical to the Version B frame, but the cam is different. The Version D cam has one less row of teeth, giving a (4.5)^3(4.3)^2(4) tooth pattern. The separation between the rows of teeth is essentially unchanged, but the cam face is shorter. The Version D cam toe is slightly more rounded than the Version B cam toe. The teeth on the Version D cam are slightly smaller than the teeth on the Version B cam.

Comments

The final row of teeth on the Version B ascender never come into play, so removing them did not harm. I suspect that removing another row or two would not have hurt either. I notice no difference in the performance of the Version B and D cams.

One reason that I have so many of these is that I use these regularly in some of my favorite climbing systems, although I prefer the versions with the wear pins, for the obvious reason.


Modified Version D
(#1905)

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 pair of ascenders directly from Walter Marti (inventor and manufacturer of the Jumar) in March 1989. They were given to me as a gift so that I could evaluate them for the article I published in The Nylon Highway #29. I acquired a second pair on eBay from Caleb Laurence at Laptop Specialties in 2012.

Version E is 179 mm. tall, 78 mm. wide, 37 mm. thick, and weighs 274 g. It is identical to Version D except two holes have been drilled near the top and bottom of the rope channel, and a 4 mm. stainless steel is press fit into each hole. The pins are partially exposed on the inside of the rope channel.

Comments

Version E differs from Version B in two ways: it incorporates the new cam introduced in Version D and the wear pins introduced in Version C.


WAG Jumar
(#273, 2176)

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 pair of ascenders from International Military Sales in 2009. I acquired another pair in 2017 as part of Bob Thrun's collection.

These jumars are 178 mm. tall, 78 mm. wide, 36 mm. thick, and weigh 278 g. each. The only difference between this pair and Version D is that the cam rivet on these has a solid head in the rear rather than a rolled head.

The front of the frame is stamped with a "0" above the cam rivet.

Comments

I bought these new in 2009, thinking that they must be Fritschi Jumars, but apparently they are not. The stickers behind the cam say that these were made in February, 1999. The instructions identify the manufacturer as Wohn und Arbetsgemeinschaft für Körperbehinderte Gwatt of Gwatt, Thun.

If you know the full history of Jumar manufacture after Walter Marti, please email me.

Fritschi Jumar
(#271, 2175, 2178)

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 Fritschi Jumar ascenders new on eBay from Michel Brinkman in 2009. I acquired two more pairs in 2017 as part of Bob Thrun's collection.

The Fritschi Jumar is 179 mm. tall, 78 mm. wide, 36 mm. thick, and weighs 272 g. It is identical to Version D, but made by Fritschi.

The front of the frame is stamped with an "A" above the cam rivet.

Comments

Fritschi has discontinued making this design Jumar, although rumors were that they would be coming out with a new model. I could not resist getting the last of the yellow breed.


Modified Version D
(#1905)

Front View Bottom View: Original and Modified
Front View Bottom View: Original and Modified

Technical Details

I acquired this pair of Version D ascenders from Charlotte Phillips in 2012 and modified them in 2017.

The modification enlarged the basal hole.

Comments

My motivation for modifying these Jumars was to improve the efficiency of my Mitchell rig by lowering the top ascender. Consider the left-hand photo:

Modifying the Jumar allows me to rig it without any knot or splice below the Jumar, lowering the ascender by 50 mm. While climbing, this reduces the height that I have to raise my right arm by 50 cm. for the entire duration of the climb.

Don't worry about the tie-in point being on the back of the handle - because of the sloped base on the Jumar, the entry point on the back is actually about 7 mm. closer to the grip point on the main line than the base of the eye - effectively gaining another 7 mm., making the net gain almost 60 mm.

There are two ways to enlarge the basal hole: by hand or by machine:

Warning:
Do not even consider using a twist drill in a drill press or a hand drill -
you will almost certainly ruin your ascender.