Bungee/Shock Cord for Solo Rebelay’s?

Just finished reading Andy Kirkpatrick’s  Me, Mysef, and I. I noticed he prefers to rebelay his lead line with 3mm 1.5 meter bungee cord loops to give the system more dynamic properties.

I’ve always used a dyneema sling for my rebelay’s but have also not taken any significant solo falls as of yet. Has anybody had any experience with using shock cord/bungees for this application? 

Andy has soloed far more than me but I don’t see the point of bungees.

I use a Klemhiest knot on my rebelays. A Klemhiest knot is a one way type prussik. When you fall, the rope is pulled in the opposite way and the knot releases. When you reapply weight to the bottom end of the rope, they will re-grab the rope.

I disagree with Andy, and agree with Mark.

You can use anything to rebelay your lead rope, to keep it from autofeeding through your [aid] solo belay device - bungy cord will work, so will rubber bands. The problem with these rebelay techniques is that they don't take your weight while you are jugging, and you lose the second benefit of the rebelays which is to prevent rope abrasion while cleaning.

A long inverted Klemheist knot works the best as a rebelay, and if you get the tension in the lead rope just right [an art, not a science] then when you clean, your weight is taken by each successive rebelay above you, thus completely eliminating any rub points [assuming you put the rebelay just before a rub point].  You really have to practise this - a lot - because too much tension in the lead rope will cause all of the Klemheists to slip when you jug and clean, thus causing your rope to rub and potentially abrade.  

Making the Klemheist long means that in the event of a fall, the lead rope can stretch - especially if you have incorporated your pig and a Screamer into your anchor to create dynamism - and the rope will not pull tight on the Klemheist mid-pitch, thus increasing your Fall Factor.  But as Mark points out, the Klemheist is a one-way knot [at least in theory] so if it's too short and the rope stretches too much, it should slip.....

Cheers, eh?
Dr. Piton

Has anyone actually gotten an inverted klemhiest to release during a fall/upward pull on the rope? I just can’t recreate this. Seems reasonable to assume they won’t and account for rope stretch by using successively longer rebelays. But at the end up of a long pitch that’s a lot of stretch! (and more if incorporating screamer/haulbag into the belay)

Peter Zabrok wrote: But as Mark points out, the Klemheist is a one-way knot [at least in theory] so if it's too short and the rope stretches too much, it should slip.....

To what extent has this been tested or tried in a real-world scenario on rock? I seem to remember a comment Mark made that alluded to having done so, but I can't find it.

I'd also love to hear some thoughts on the art of getting your rope tension correct. I get what would go wrong if the rope's too tight (it just rubs against the edge anyway), but having it too loose seems like it it would just introduce some extra slack which might not be a huge deal. That being said, I'm thinking about this while sitting on my couch on a rainy night so maybe my thought process isn't complete.

peterfogg wrote:

To what extent has this been tested or tried in a real-world scenario on rock? I seem to remember a comment Mark made that alluded to having done so, but I can't find it.

I'd also love to hear some thoughts on the art of getting your rope tension correct. I get what would go wrong if the rope's too tight (it just rubs against the edge anyway), but having it too loose seems like it it would just introduce some extra slack which might not be a huge deal. That being said, I'm thinking about this while sitting on my couch on a rainy night so maybe my thought process isn't complete.

It does take two hands to properly tighten the knot.

Pete has soloed El Capitan nine times and co-authored the primo manual Hooking Up.

When you do the knot correctly it will allow for upward progress of the rope in case of fall but absolutely locks the rope for downward pull for the rebelay.

I just soloed most the way up a Yosemite big wall and the idea is you have a little loop at each piece when you're looking up as you're cleaning it.

You would soon find that doing this is not really optional otherwise the weight of the rope pulls slack into your system

I am aware of who Pete is, and I've done enough soloing to know what happens if you don't have a klemheist (ask me how I know this...). Just wondering to hear from the man himself about what he does to get that tension just right.

peterfogg wrote:

I am aware of who Pete is, and I've done enough soloing to know what happens if you don't have a klemheist (ask me how I know this...). Just wondering to hear from the man himself about what he does to get that tension just right.

Like it says in his book and if you practice it, you tighten it with two hands

A. B. wrote:

When you do the knot correctly it will allow for upward progress of the rope

Does it really though? In theory it should but in practice (at least as far as I can tell) it ends up loaded in an oblique way which prevents that upward progress

dot conn wrote:

Does it really though? In theory it should but in practice (at least as far as I can tell) it ends up loaded in an oblique way which prevents that upward progress

Yes.  It does. The way the loop is locks the rope I when pulled down. The rope slides upward through the knot, which would only matter if you fell.

If you fell, the rope would pull up distributing the shock through the misc. pieces as intended.

I generally don't fall when I solo.

I solo to cruise, not to push my limits. 

I’m with Dot Conn on this one..

I always thought that the slack in the system to accommodate rope stretch or a haulbag dynamic anchor came from the length of the Klemheist loop.. shoulder length will give you 30”+ of travel in the system.

If you are expecting your Klemheist to let rope feed through if the system is weighted upwards (in a fall) I just can’t make that happen (in tests) the knot appears to only be “1-way” when being pushed or pulled in the same direction.. 

I was soloing Zenyatta when I fell and stopped right at a rebelay. It had released and when I was cleaning the pitch, it had re-engaged. 

Quinn Hatfield wrote:

I’m with Dot Conn on this one..

I always thought that the slack in the system to accommodate rope stretch or a haulbag dynamic anchor came from the length of the Klemheist loop.. shoulder length will give you 30”+ of travel in the system.

If you are expecting your Klemheist to let rope feed through if the system is weighted upwards (in a fall) I just can’t make that happen (in tests) the knot appears to only be “1-way” when being pushed or pulled in the same direction.. 

Well, in a sense you are correct in that when you're going up you use successively longer slings for the rebelays.

Many here climb harder and know more than I do

A. B. wrote:

when you're going up you use successively longer slings for the rebelays.

That’s interesting. I’ve never heard that..

It seems that would only be necessary if the Klemheist does not allow rope through on a fall? 

There is no need for successively longer slings.