MoapaPk wrote:

seb wrote:The rope i'm currently looking at has a max haul load of 480 pounds any body know of any ropes that maintain the weight (1.9lbs) but with more strength any body got any ideas?

http://www.sterlingrope.com/product/456 ... /_/RIT_900
This is the rope im thinking about

That rope is strong enough for a normal rappel-- MBS is similar to an 8mm nylon rope- but it looks like a coreless rope; I don't really know how such ropes behave in devices. Are you looking for a technora-type rope (with high melting point) for a particular reason? Where did you come up with the 480 lbs number - the listed working strength in 420 lbs, and that's a safe working limit for more general use. A normal rappel doesn't generate huge forces.

I'm pretty sure I've seen this stuff in pre-sewn prusiks. It tends to flatten out, which is good for a prusik, but I don't think that is what you want, and the "diameter" is a bit misleading. Sterling makes slightly heavier technora-type (let's say aramid, technora may be a trademark) , thin ropes with cores-- either nylon of more aramid.

I've rappeled on 15mm nylon webbing, but I can't say that's really optimal.

EDIT: I just checked my 100' of Sterling 7mm nylon -- 2.24 +/- 0.02 lbs.
I also check the sterling site again -- here is a pre-sewn prusik made out of RIT 900. Enlarge the image and you'll see how the stuff tends to flatten out.
http://www.sterlingrope.com/product/155 ... llow_Block

The 480 number was from memory and can you recommend any super fine abseiling cord.

Have you ever done what you are proposing to do? Not just rapelling, but using fireman search line, or other non climbing ropes for climbing functions, or super skinny ropes? It is much easier to lose control with even an 8mm vice a 9,8mm. Going on a 6,8mm cord of unknown consistency without special gear is unwise. You are asking questions which makes me think you may not have the experience to keep yourself safe. The anchor construction is probably much more important than the cord or device, for instance.
Sometimes there is a good reason for doing things the "standard" way. And if you want to get creative, that's great, but understand the pitfalls first.
You've received a number of responses with very good ways to add friction for these types of setups.
But they all assume you already have a standard baseline of knowledge and experience.

Our just use your shoe laces. You are already carrying the weight for the approach, so they essentially don't weigh anything.

The 480 number was from memory and can you recommend any super fine abseiling cord.

As far as I know, the smallest diameter rope made specifically for abseiling is 8 mm. Thinner cord that pertains to climbing is usually used for haul lines or fixed lines, though can be used for emergency rappels.

Haul lines are typically not as stiff, thus don't provide as much friction.

Looking back at the original post though:

Looking at buying some super skinny abseiling cord (6.8mm)

What made you think that a fireman's search line is an abseiling cord?

I'm starting to think that your post are trolls and are not actually meant to be serious. (Take a look at the profile).

I'm guessing these threads are actually trolls. Maybe I should delete them?

If they aren't trolls or the poster is leading us on, then the person is simply unwise.

I just looked at the profile. I'm thinking seb is just young, probably hasn't done enough of this stuff to get a real feeling for the effect of rope diameter and stiffness on comfort, braking and retrievability (i.e. if he is forced to a munter hitch on a double-strand rap). At 16 I tried lowering myself on parachute cord; it didn't work as well for me as it did for Batman.

Seb, for 100', it's less than a pound difference between 7mm and 8mm. With all the other stuff you'll need, that pound will start to seem insignificant. An 8mm, 60m canyoneering rope (dyneema core, polyester sheath) comes in at about 5.6 lbs.

You can save almost a pound on the harness weight, if you go to a pure alpine harness vs a multi-purpose climbing harness; but I'm not going to elaborate on that, for fear where it might lead. Start off conservatively.

MoapaPk wrote:You can save almost a pound on the harness weight, if you go to a pure alpine harness vs a multi-purpose climbing harness; but I'm not going to elaborate on that, for fear where it might lead. Start off conservatively.

Dont worry it may be hard to believe but i have enough sanity to not just go for a ultra light swami or even worse a bit of para cord round my waist.

seb wrote:

MoapaPk wrote:You can save almost a pound on the harness weight, if you go to a pure alpine harness vs a multi-purpose climbing harness; but I'm not going to elaborate on that, for fear where it might lead. Start off conservatively.

Dont worry it may be hard to believe but i have enough sanity to not just go for a ultra light swami or even worse a bit of para cord round my waist.

But yet you think that buying search cord and hanging your body off it is a good idea?
Hmm.
Ever think that maybe there is a reason that devices aren't sold for cord that small? Or why climbing ropes aren't sold that thin? It's not like climbers wouldn't buy it if it was super light and worked well. Just consider that for a minute, lad.
Climbers aren't exactly on love with carrying extra weight. Do if a super light alternative worked, wouldn't you see all of us rushing out to buy it?

A swami is safer than your cord suggestion, by the way.
I take my kids out on swamis I tie myself.

If you go to the climbing boards, you will find lots of discussions about the thinnest rap cord one can use... but I always get the impression the folks asking the questions have a lot of experience, and have tried using the tagline to finish an unplanned adventure.

I'm a dilettante, and I know it. I try everything either from a tree, or from a "safe" area near Calico Basin. The safe area starts from a really good anchor rock, then goes 30' down a slope increasing from 30 to 50 degrees, then 15' down a vertical stretch, then hits a wide platform, then drops a farther 20' with an overhang. This setup weights the ropes gradually, and gives me plenty of time to see if something is really wrong with an experiment, before committing to the next harder step. Every rope I get goes through an atc at least 4 times here, before I would ever think of letting anyone else use it. I test every rap device here, including munters on a variety of materials (including 15mm webbing and 7mm cord and disparate ropes tied at top).

Everyone advises the munter for thin rope. My personal advice: try a double-strand rap on the munter, repeatedly, and then try pulling the rope/webbing whatever from below. Repeat. One stuck rope can ruin your whole day.

Why not just get 100m of off the spool 7.5-7.8mm half/twin rope and back it up with a autoblock? Mammut, Sterling etc. must sell half/twin rope by he spool.
I just started using the Sterling 7.8mm nano photon and it works through a reverso just fine though extra care must be exercised.

Victoriamatt wrote:Why not just get 100m of off the spool 7.5-7.8mm half/twin rope and back it up with a autoblock? Mammut, Sterling etc. must sell half/twin rope by he spool.
I just started using the Sterling 7.8mm nano photon and it works through a reverso just fine though extra care must be exercised.

That's too heavy. The elite climbers of today don't need ropes with strong core, just a hollow sheath. Not only it's light, you don't have to worry about core shots. It's also a safer way to save weight than from using a swami tied from webbing.

seb wrote:Looking at buying some super skinny abseiling cord (6.8mm) and i cant seem to find any descenders that can handle a rope that fine any body got any ideas? Other wise i will end up having to just tie a super munter htich.

Seb,
http://www.multipitchclimbing.com/
chapter 10, section 6, shows photos of various ways of adding more friction (the photos are bigger in the PDF version)

http://www.iscwales.com/Product/RP120-M ... cenders%2F

For occasional use:
http://adventureropegear.com/cart/produ ... ucts_id=80

Figure 8 devices twist rope more than atcs

There are lots of emergency descenders for rescue cord; the rub is that most are meant for a single strand. Many "rescue systems" are meant for quick exits from burning areas -- that's why the rope is often aramid-sheathed (e.g. Technora). When someone has to leave a burning building in a hurry, that person doesn't worry a lot about retrieving the rope.