The grigri is used in yoyo systems for single rope work. It has a limited range of rope diameters it will work with. Petzl lists it as 10mm or 11mm. Most climbing rope is larger (but not all).

Do you use the grigri alone or is there some backup system incase of failure?

prosigna;

I have been using the GriGri on a single, static (BlueWater) 11mm rope, without a back-up. It works fine, but as I mentioned in my previous post, it's not really what the GriGri was designed for. That's why I went out and bought the Petzl Stop today, which is specifically designed for descending 9 to 12mm static rope, and does not require a backup.

The petzl website lists the Stop as being for 10-11mm rope same as the grigri. Did the product itself have a different spec than the website specs?

As far as backup goes - I do not trust any mechanical device without a backup. When I first rappelled off a clif I went down with only a fig 8. This is how most people I know have always done it. Reading this thread shows why you should not do that. SAFETY MAN - SAFETY.

The stops ability to self-belay is nice but what if it jams? What do you do? Scream and fall I guess.

prosigna;

The _meta_l stamp on the "Stop" says 9 to 12mm, but I'm also aware that the Petzl website indicates a rope diameter of 10 to 11mm. However, the literature (on the site and in the booklet) says the unit is certified down to 9mm.

I'm not sure what you meant when you said, "The stops ability to self-belay is nice but what if it jams? What do you do? Scream and fall I guess."

A jammed device may stop the descent, but it will not cause a fall. In the unlikely event of a jam, I will simply unweight the device using my ascenders, and use my back-up rappel device, a Black Diamond ATC, to continue descending the rope. I suppose, in theory, the "Stop" could suffer some sort of catastrophic failure. But then, the tree could also fall over, or get hit by a meteor.

Jay, you sneaky rascal!!

I've referred to Jay ("kernsloth") many times in my posts; he's been my climbing mentor and friend.

He also happens to manage an arborist supply business. That Business, Blue Ridge Arborist Supply, IMO, happens to be owned and operated by some good folks who are interested in supplying good service at good prices.

Take a look at the _link_ Jay provided.

I would be absolutely amazed if you were not fully satisfied with them.

I have been practicing w/ SRT using CMI ultrascenders and I have a question. After you reach the top of the branch but you are still hanging from the rope what piece of equipment do you use to get down and how do you install it.
What is your favorite method?
I did three climbs today and tried 3 techniques .
First ascended and tried to come down w. a rack. (Full-size rack). It was hard to install and disconect the ascenders while still hanging from the rope. I finally have to climb on a branch and do the transfer there while resting on the branch and came down. What I did wrong?
On The second climb I tried the figure eight to descend. It was easier to install while still hanging on the rope but them I could not remove the bottom ascender so I did have to climb on the branch to do the transfer from ascending to descending gear. The descent was a little too fast and whitout much control for my taste because of the single ropegoing thru the figure 8 but safely arrived at the ground.

For the final climb I instaled a GRIGRI to the bottom of the rope and hanged it to the side loop of the seat harness. When I reached the top I was able to pull the GRIGRI up, remove the top ascender and the bottom ascender while still hanging from the line and them descend safely and under complete control. I have used the GRIGRI before with a technique Panama Joe showed me in NE called the Yo-Yo and I see how the GRIGRI is a prefered piece of equipment for the job. Any suggestions on other techniques to try will be welcomed.