Compact Bulldog Bone

surveyor

Well-Known Member
#1
Tends slack well, releases smoothly, and about 13-14 oz. Midline attachable.


It has been suggested that I edit this first post to show the current state of the Bones, so here goes.
The standard compact Bulldog Bone comes with three interchangeable bollards on the top arm that can be interchanged with tools and a new SS cotter pin. Here is an excellent video that John has made of this standard Bone.
I also make a compact adjustable Bone which uses a SS 10-32 machine screw to move the bollard in the top arm of the Bone to adjust the gap where the rope is installed. This bollard is held from rotating, so it wears faster than the standard Bone bollard, but replacement bollards and spines can be obtained from me if desired (the spine being the part that connects the top arm to the bottom arm) I should mention that a Rock Exotica nano swivel can be installed directly on either Bone, replacing the teardrop attach point at the bottom arm.


I also make a lanyard adjuster called the BOLA, which is shown here in another video made by John!
 
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surveyor

Well-Known Member
#11
Well, the two arm OAR self advances DdRT. The Bulldog Bone tends slack better without an added pulley and is more of a SRT device, although it works fine DdRT as long as the standing part of the line is clipped into the bridge, but you have to advance and then manually take up slack. At 12 oz. the Bulldog Bone is about 10 oz. lighter than the three arm OAR. The Bulldog Bone also does not use rollers, however a small 1/2 inch roller can be added to the top arm to make it a bit grippier.
 

surveyor

Well-Known Member
#12
OK, I have added a swivel lock link to the upper arm of the Bulldog Bone. I also moved the swivel link 1/8" closer to the upper pivot and added a 5/8" roller (which can be swapped for a 3/4" roller or a 1/2" roller to add slightly more or less grip). here is a picture of the latest Bone in its collapsed mode, notice the size of the bone in relation to the carabiner.

 

surveyor

Well-Known Member
#14
I have used it both DdRT and in an O rig configuration. It is a bit tight but it does work. It also will advance as a three to one set-up on a single line.

Because of my time and expense involved, I have been considering the idea of a rent to try/own the Bulldog Bone, along with a signed disclaimer.
 

macswan

Well-Known Member
#15
I have been using the Bone for the last week, and it is really fantastic. It stands up next to the rope runner. I was able to find the sweet spot for descent much faster. Hooked to a chest tether it tends just as well on ascent. And it is by far the easiest friction device of any kind (even hitches) to get on and off the rope. I have been enjoying it immensely. The size is great. I am definitely still dialing it in. But I like it just as much as my rope runner. They each have there own idiosyncrasies. We have another mechanical friction device! Thank you surveyor.
 

yoyoman

Well-Known Member
#19
Gordon,
I like this design, good use of the links.I think it is much more versatile than the OAR design which basically consisted of 3 Bends. your new design has a bend followed by a progressive pinch similar to the Rope runner.
one word of caution, and this applies to your device as well as the Rope runner and to some extent others. the top control arm is quite large, if you slip or inadvertently put pressure on that top arm you go for a fast slide. as I mentioned this goes for other similar devices but the bigger that arm gets the more likely it is to happen.
All said it looks great!
 

yoyoman

Well-Known Member
#20

Here's a short vid showing how EASY it is to get the Bone off an on rope.

It took me forever to figure out how to embed this thing, holy crow. Hats off to all you actual video makers.
maybe it's just my phone, but when I watch the video its just voice and a black screen.
 
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