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Been here a while
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- Casablanca
Whats the draw to a 9mm bone? For use with captain hook or similar?
Compact Bulldog Bone
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I’m interested in a twin 8mm rig.
Serf Life
Been here much more than a while
- Location
- Maine Island
Looks super neat, can you explain the application for the double as pictured?
I had a rec climb yesterday using two systems that got me thinking about TRT again as well but have yet to experiment. Logistical nightmare in a short wide silver maple - would have loved to be able to manipulate two lines from the same point of friction like I’ve seen on some of woodenhand’s stuff. Casting my vote for a twin8 bone!
The twin device pictured is a proof of concept (I called it the Crab in an earlier thread). My thought was you could use it with a pulley above and a foot ascender on either foot. It works in that manner as one side ascends then the other.
However it seems good also for a twin line configuration, when you might have two separate lines coming in from different angles, say for work positioning. Or you could use it as SRT allowing the rope to be retrieved like you would a a double line.
However it seems good also for a twin line configuration, when you might have two separate lines coming in from different angles, say for work positioning. Or you could use it as SRT allowing the rope to be retrieved like you would a a double line.
Serf Life
Been here much more than a while
- Location
- Maine Island
Neat thx. I climb as minimal as possible and haven’t played much with a system like that. Need to do some rec climbing to expand some skills! Bought an OG a few yrs ago and recently got an elongated bollard present, but a 9mm for the hook line sounds tempting…
Would love both on one side for easy one handed descent/positioning and whatnot but I also have not done anything with twin ropes anyway. it sure is neat! Seems way specialty but would love to see something like that available
TRT
Anyone climbing TRT? Twin rope technique. Looking to discuss techniques and anchors, systems, really all parts. Curious what others are doing as I enter this very strange climbing style... @oceans any input? Trying to figure out a climbing system, preferably hitch based...
www.treebuzz.com
I remember that, and I like it, but the 180 opposed layout is my initial hesitation. If they were side by side I could jump on board!
Lignotuber
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- Socal
I received my 9mm rope bollards mod for the bone this evening. Got it for top rope solo rock climbing. Seems to work good with my 8.9mm rope (tiny bit of creep) and good with my 9.7mm after the profile is flattened a bit. I didn't want to bug Gordon regarding the taper pins so thought I'd share what I came up with to remove them with limited tools on hand lol. Basically cut the tip off a nail and filed it flat, then popped it through one hole onto the pin and put the pin in the hole of a 3/8" extension. Proceeded to tap it with some dykes. Worked great lol. I'll try and get a session in soon with a microtraxion as a backup on ascent. Figured I'd share Incase anyone was interested.
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Good idea, and thanks for the feedback about use with these rope sizes. I have used an old drill bit in the same way, but the one I was trying to extract refused to budge, some are harder to extract than others. I have begun to set the taper pins by squeezing them in with pliers, rather than press fitting them, with the thought that they might be removed a bit more easily to facilitate installing this 9mm bollard.
Lignotuber
Participating member
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- Socal
Update on the 9mm bollards after a climb top rope soloing. So far worked great on the 8.9mm rope. It will occasionally (~1/10 falls) slip through the device for and let you drop 3-8 inches when falling before it catches. Same with the 9.8mm. I used a microtraxion as a backup and it will sometimes jam up against it a bit when this happens. As of now it's not a big deal to me, just climb a little and everything is back to normal. The rope can get a bit offset on the bottom bollard on decent if you're not mindful but it worked fine regardless. I also noticed a bit more heat on the device, probably because the top bollard is more exposed and I'm not wearing gloves. Overall I really dig it, I'll continue to test it top rope soloing on rocks and trees. Also worked well in MRS while rappelling and removing my anchor.
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- Location
- Midcoast Maine
Sorry, I'm just chiming in now - been on some sequoia climbing trips with Ancient Forest Society, and tree work back here in Maine has been super busy. Not to mention I'm a technotard - not my strong suite.
Ancient Forest Society has a number of research projects studying the giant sequoias in the Sierra Nevada, and because most of these trees are in the 250'-300' range, we need 600' ropes. Hence the need for 9mm as the volume/weight in the pack becomes an issue. Seems fairly typical with folks working taller trees. At that length, the volume/weight difference even between 9mm and 3/8" is significant. In the past I've been using a knee ascender with jumar, both tethered to bridge set up, and switching over to a grigri for descent. The 9mm and 3/8 ropes that we've been using thus far are all Sterling HTP which is pretty firm.
When I tried this BD modified bollard set up on some 8.8mm dynamic line, it functioned adequately except for minor creep. This was just a test, as ascending dynamic 8.8 for any significant distance is like climbing a rubber band - pretty inefficient! That dynamic 8.8 being much softer lay than the Sterling HTP, would slip off the side of the bottom bollard during descent. Lignotuber, sounds like you observed that as well. I have not noticed that problem with 9mm HTP thus far.
The 9mm BD set up does get pretty darn hot during 200-300' descents, definitely thankful for the little black rubber nubs for insulation! Then again, it's hard to imagine what device wouldn't get smokin' hot during several hundred feet of friction focused on a narrow 9mm path! I do think the grigri might still get a bit hotter on lengthy descents on the 9mm, and has a much narrower "sweet spot" for control - much jerkier.
Nearly all the 9mm climbs I've done thus far have been on the oblong stock aluminum top bollard with Gordon's additional top and bottom bollards for conversion to 9mm. Gordon's suggestion that the oblong stock bollard would be more durable on the harsh 9mm seems spot on. It's a bit of a trick getting the stiff 9mm HTP between the stock oblong bollard and the 9mm top bollard. I do find it helps if I slot the rope in from the top down, rather than slotting it in from below the top bollards up into the top bollards. I have wondered about grinding an angle on the outside edge of the 9mm top bollard to make it easier to slot the rope into place. Wonder what your thoughts would be on that Gordon??
I should put in some 9mm rope time with the adjustable brass top bollard set up just to see how it moves over some time.
Overall this BD mod works great on 9mm for both ascent and descent! Very broad sweet spot of friction control on descent, much better than anything else I've tried yet, including the TAZ Luv2. My only challenge with this setup is that it is very fiddly switching the BD back to stock to run on other rope diameters. This process while aloft has lots of exposure for dropping small critical metal parts and requires pliers/tools. I'd be curious to try just basic cotter pins (or something like that) through the ends of the friction links instead of the tapered pins? Could at least ditch the pliers if that worked. The cotter pins could get dislodged while working aloft much easier than set tapered pins. Switching rope diameters during work in the sequoias and other tall trees seems common because we often switch from a 9mm access line to a much shorter 11mm +/- canopy line to climb/work the top, and then descend the 9mm back down. That's a fair bit of switching back and forth in one tree. Alternately, I might just get 9mm canopy lines to work the top. Hmmmmm... have to keep pondering that little puzzle : )
Gordon, thank you so much for all your continued innovation!! Been working/loving the BD for over a decade... and now this 9mm mod for a totally different context! Loveit!
Ancient Forest Society has a number of research projects studying the giant sequoias in the Sierra Nevada, and because most of these trees are in the 250'-300' range, we need 600' ropes. Hence the need for 9mm as the volume/weight in the pack becomes an issue. Seems fairly typical with folks working taller trees. At that length, the volume/weight difference even between 9mm and 3/8" is significant. In the past I've been using a knee ascender with jumar, both tethered to bridge set up, and switching over to a grigri for descent. The 9mm and 3/8 ropes that we've been using thus far are all Sterling HTP which is pretty firm.
When I tried this BD modified bollard set up on some 8.8mm dynamic line, it functioned adequately except for minor creep. This was just a test, as ascending dynamic 8.8 for any significant distance is like climbing a rubber band - pretty inefficient! That dynamic 8.8 being much softer lay than the Sterling HTP, would slip off the side of the bottom bollard during descent. Lignotuber, sounds like you observed that as well. I have not noticed that problem with 9mm HTP thus far.
The 9mm BD set up does get pretty darn hot during 200-300' descents, definitely thankful for the little black rubber nubs for insulation! Then again, it's hard to imagine what device wouldn't get smokin' hot during several hundred feet of friction focused on a narrow 9mm path! I do think the grigri might still get a bit hotter on lengthy descents on the 9mm, and has a much narrower "sweet spot" for control - much jerkier.
Nearly all the 9mm climbs I've done thus far have been on the oblong stock aluminum top bollard with Gordon's additional top and bottom bollards for conversion to 9mm. Gordon's suggestion that the oblong stock bollard would be more durable on the harsh 9mm seems spot on. It's a bit of a trick getting the stiff 9mm HTP between the stock oblong bollard and the 9mm top bollard. I do find it helps if I slot the rope in from the top down, rather than slotting it in from below the top bollards up into the top bollards. I have wondered about grinding an angle on the outside edge of the 9mm top bollard to make it easier to slot the rope into place. Wonder what your thoughts would be on that Gordon??
I should put in some 9mm rope time with the adjustable brass top bollard set up just to see how it moves over some time.
Overall this BD mod works great on 9mm for both ascent and descent! Very broad sweet spot of friction control on descent, much better than anything else I've tried yet, including the TAZ Luv2. My only challenge with this setup is that it is very fiddly switching the BD back to stock to run on other rope diameters. This process while aloft has lots of exposure for dropping small critical metal parts and requires pliers/tools. I'd be curious to try just basic cotter pins (or something like that) through the ends of the friction links instead of the tapered pins? Could at least ditch the pliers if that worked. The cotter pins could get dislodged while working aloft much easier than set tapered pins. Switching rope diameters during work in the sequoias and other tall trees seems common because we often switch from a 9mm access line to a much shorter 11mm +/- canopy line to climb/work the top, and then descend the 9mm back down. That's a fair bit of switching back and forth in one tree. Alternately, I might just get 9mm canopy lines to work the top. Hmmmmm... have to keep pondering that little puzzle : )
Gordon, thank you so much for all your continued innovation!! Been working/loving the BD for over a decade... and now this 9mm mod for a totally different context! Loveit!
As far as the taper pins go, I think you could set them in by squeezing in with your hand, and then they actually stick quite well, but allow removal by hand also. You could carry spares aloft. The taper pins can be had at mcmaster. (size 4 I believe)
As long as the rope goes in on the top bollard(s), I prefer to leave the bollard full width across the width of the friction link. If the Bone grips reliably without the bottom small bollard, then I think that will be OK
Back up should be used with 9mm. added friction below the Bone would be helpful with long descents.
Thanks Brian for urging me on this, and for your feedback. Gordon
As long as the rope goes in on the top bollard(s), I prefer to leave the bollard full width across the width of the friction link. If the Bone grips reliably without the bottom small bollard, then I think that will be OK
Back up should be used with 9mm. added friction below the Bone would be helpful with long descents.
Thanks Brian for urging me on this, and for your feedback. Gordon
That was a very nice and thorough review, thanks! Changing the BD in the tree for use on different rope diameters sounds like a horrible idea. Just get a second BD that is set for the larger line. Change-overs would be fast and safe.
Lignotuber
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- Socal
3rd outing on the rocks with the 9mm BDB on 8.9mm rope. Worked flawlessly.
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