What's the Best Rope for the Prusik? Type? Diameter?

The purpose of this entry is to inquire what type of rope that the experienced climbers are using on their Prusiks.

I'm using 8 mm nylon cord to Prusik on my 11mm polyester (New England Fly) rope.

Because polyester has better properties under friction than nylon, are the experienced climbers using an 8 mm polyester cord? Is everyone "happy" to use nylon?

I'd like to experiment with a polyester cord on the Prusik if someone has a supplier recommendation.

Lastly, what's your preferred cord diameter on the Prusik?

Regards,
JimK

Jimk, from what I've seen, using an 8mm prusik on 11mm line should be just fine. I prefer polyester. Often nylon and polyester are advertised as having same or similar melting points. But in the trees, use has shown me that polyester seems less likely to melt, and when it does incur a bit of melting, it's more likely to be usable afterwards.

love
nick

A good source for polyester rope is http://www.sailnet.com/ New England Sta-Set (not Sta-Set X) is a very supple polyester braided rope rated at 3000 lb in 8mm. The T-900 has Technora/Spectra core covered with polyester, rated at 7300 lb in 8mm, but is much stiffer than Sta-Set. I'm very happy with a VT hitch using 8mm T-900 on Fly rope for DRT.

Jepson "The Tree Climber's Companion" 2nd edition reports that 3 wraps are needed as a minimum. It's frequently stated in communications to use 3 wraps. The more wraps, the more friction and reliability of hold. It all depends on conditions: cord stiffness, cord diameter, cord type and moisture conditions. The climbing rope is a factor also in how well the Prusik operates. Prusik is only for ascent, not descent. It will sometimes lock. Thus one needs another system to unload the stuck Prusik. It can be used as a back-up to a figure-8 descending device. It's not a simple wrap around the rope and go system. There's a level of skill required to manage it. Low and slow caution is the appropriate action. My rule of thumb is to never rely on one single type of rope system. In other words, my preference is to use two different types of friction hitches on any given ascent. If conditions exist to cause one to fail/slip/lock, the thought is that the other friction hitch would not fail under the existing conditions.

Hi, Jim--

You say:

Originally posted by JimK
My rule of thumb is to never rely on one single type of rope system. In other words, my preference is to use two different types of friction hitches on any given ascent.

I'm not sure what you mean by this; are you saying that you use, for example, both a Blake's hitch and a Prusik secured to your saddle during ascent? If so, how do you manage them?

I may be missing something very obvious: one of the dangers of being a novice!

I have been using a Blake's on my bridge, and a Prusik for a foot loop. I have enough difficulty managing those plus all those hands and feet that I seem to carry with me!

Jim,

Your description is the variation I had in mind. For SRT, I would use one type of friction hitch to the harness and another type for the foothold.

Regards,
JimK

Thanks, JimK.

I meant also to reply to your original question about a Prusik's diameter: "On Rope" suggests that the Prusik rope's diameter is about 70% that of the climbing rope. So 8mm for an 11mm rope sounds right.

I'm interested in looking at some of the polyester, as you, Nick, and BlakesHitch have discussed. I'm thinking that I'll first try a footloop Prusik of this, and then possibly try a split bridge of 0.5 inch polyester for my Blake's hitch.

For ascending SRT, I don't use prusiks, but ascenders, for ease and speed. However, if I were, I'd choose a Klemheist or Krutzklem (Hedden knot), over a trad three wrap prusik any day. Or better, try a distel, schwabisch, or even a french prusik--anything that is easier to slide after loading.