Aiolos Silenos
Aiolos StarStarStarSilenos



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Front Rear Top
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Technical Details

I acquired my Alpidex Aiolos from David Wain in 2017.

The Alpidex Aiolos is a notched belay tube. Mine is 51 mm. long, 45 mm. wide, 112 mm. high, and weighs 93 g. It is forged from aluminum alloy and then soft anodized. It has two slots and a plastic-covered cable keeper. The slots are 31 mm. long and 14 mm. wide. The top of the Omega oval carabiner that I use for comparing belay tubes sits 19 mm. below the ends of the slots.

One side is printed with "alpidex" inside a round-cornered rectangle, a rigging illustration, "105," "15P1," and "Ø8mm-11mm ."


The Alpidex Aiolos is one of the following closely-related notched belay tubes:

Image Device Side Keeper
Alpidex Aiolos Alpidex Aiolos Solid 3.8 mm.
Black Diamond ATC-XP, Version A Black Diamond ATC-XP, Version A Solid
/w Logo
4.7 mm.
Black Diamond ATC-XP, Version B Black Diamond ATC-XP, Version B Solid 4.7 mm.
Image Device Side Keeper
Black Diamond ATC-XP, Version C Black Diamond ATC-XP, Version C Solid 4.7 mm.
Black Diamond ATC-XP, Version D Black Diamond ATC-XP, Version D Solid 4.7 mm.
Black Diamond ATC-XP, Version E Black Diamond ATC-XP, Version E Open 4.7 mm.
Image Device Side Keeper
BlueWater Guardian BlueWater Guardian Round Hole 3.8 mm.
Climb X XP Climb X XP Solid 3.8 mm.
Kailas Kguard Kailas Kguard Solid 3.8 mm.

Each of these is 53±2 mm. long and 46±2 mm. wide. Their weighs range from 64 to 95 g., with variations in the lightening holes (or their absence) accounting for the differences. Their slots are all 32±2 mm. long and 14±1 mm. wide. They all have plastic-covered cable keepers, with the Black Diamond keepers being and stiffer than others.

The Black Diamond ATC-XP was the first of these to appear, by many years. Version A was an improved version of their ATC. From there, the basic design evolved and similar devices appeared from others.

Each of these has V-slots to give additional friction for belaying or rappelling. Each side of each groove has three V-shaped slots, giving the grooves "teeth" to grip the rope more effectively. These teeth act to guide the rope deeper into the slot, in much the same manner as the teeth on the Wild Country Hand ascender work. The teeth do not have the narrow angle found on the Trango Jaws or its equivalents, so they do not create the same wedging action. For this reason, I find these less effective than the Jaws family. On the other hand, the teeth on the ATC-XP provide a larger bearing area for the rope, which helps reduce localized heating. These are more massive than the ATC, but will still overheat on long rappels.

The ATC-XP and equivalents are rigged like the ATC, with the V-slots on the brake hand end of the rope. Alternately, they may be reversed to disable the V-slots.

Some of these have a hole or an opening in the sides and the central rib. When present, these reduce the device's weight, but also reduce the devices' surface area for rejecting heat.

My preference from this set is for the Black Diamond ATC-XP, Version C, which is the lightest of the group and has the stiffer keeper; however, it requires closer thermal monitoring on rappel.


Front Rear Top
Front Rear Top
Left Right Bottom
Left Right Bottom

Technical Details

I acquired my Alpidex Silenos from David Wain in 2017.

The Alpidex Silenos is a notched belay tube. It is forged from aluminum alloy and then soft anodized. Mine is 60 mm. long, 48 mm. wide, 117 mm. high, and weighs 75 g. The slots are 34 mm. long and 15 mm. wide. The top of the Omega oval carabiner that I use for comparing belay tubes sits 14 mm. below the ends of the slots. The keeper is a stiff plastic-covered cable.

One side is printed with a rigging illustration, "alpidex" inside a round-cornered rectangle, "104," "16P1," and "Ø8mm-11mm ."


I like this design enough to give it three stars: StarStarStar

The following notched belay tubes, including the Alpidex Silenos, are essentially the same device:

Image Device
Alpidex Silenos Alpidex Silenos
Apex Rock Mako Clymb Apex Rock Mako Clymb
Climb X Mako Climb X Mako
Climbing Technology Double V-Row Climbing Technology
Double V-Row
Image Device
Edelrid Lotse Edelrid Lotse
(a.k.a. Multigrip)
Salewa Tubus, Version A Salewa Tubus, Version A
Salewa Tubus, Version B Salewa Tubus, Version B
Singing Rock Hornet Singing Rock Hornet
Image Device
Trango Jaws, Version A Trango Jaws, Version A
Trango Jaws, Version B Trango Jaws, Version B
Zero-G G-Wedge Zero-G G-Wedge
(a.k.a. Multigrip)

Each of these is 60±1 mm. long and 48±1 mm. wide, and has a weight in the 76±3 g. range. Their slots are all 33 mm. long and 15 mm. wide.

NotchesThese are just like many other devices except for one little difference, but that difference makes any of these a much better device than those others. The special feature is the teeth. First of all, if you don't need them, turn the device 180 degrees and they are out of the way. On the other hand, if you want more friction, then these teeth canprovide it. This is the only device design of this size and weight that I feel comfortable rappelling my 9 mm. haul line on. With any others, I never really felt completely in control (to be fair, I haven't tried this on the the Omega Pacific SBG or the Simond Cubik). The extra control is well worth carrying the extra 15 or 20 grams. One caution: like all belay tubes and tubers, these can get very hot on rappels.

I borrowed the following paragraphs from Trango's web site, although they should apply to any of the devices in the table:

Jaws stops better than most belay/rappel devices. The addition of the V notches really grabs the rope, assisting in slowing down the fall. In lab tests using a UIAA drop tower, an 11 mm. rope, an 80-kg weight with a fall factor of 1.2, and a clutch holding the rope with a 50-lbf slip threshold, we found the following results:

 Pyramid/ATC/Tuber style devices  16" - 20" slip, no rope damage
 GriGri  1" - 3" slip, no rope damage
 Jaws  6" - 8" slip, no rope damage

Jaws allows you to adjust the rope friction during a rappel. By flipping the rope out of the notches and over the side plates at the start of a long rappel, you can reduce the friction the device gives you at the start. When the rappel begins to speed up as you get closer to the ground, flip the ropes back into the notches to slow it down.

You must rig Jaws correctly. It's not symmetrical so you need to be sure the notches are on the brake hand side of the rope, not on the side which goes to the leader. Also, because of the additional friction provided by the device you'll find that the beginnings of long rappels can be a bit jerky. The solution is to allow rope to slide through by varying the angle of your brake hand rather than just letting rope slip through. On low angle slab rappels, turn Jaws around so the notches are on the anchor side and your brake hand is on the smooth side.

The Silenos has a softer or thinner anodized coating than some of the others listed, and so it might start to wear sooner than they would.

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