The time has come to preform some maintenance on my threaded hexes. What is the best diameter for the new cord? Also, does the brand really make a difference when you're talking about cord or is it all pretty much the same as long as it is rated for climbing?

kayakerSS wrote:The time has come to preform some maintenance on my threaded hexes. What is the best diameter for the new cord? Also, does the brand really make a difference when you're talking about cord or is it all pretty much the same as long as it is rated for climbing?

Use the biggest cord that fits (within reason). The brand isn't as important as the flexibility. I'd recommend the most flexible cord you can find to minimize the amount of jiggling transmitted from the rope to the piece. For maximum flexibility, use webbing, though you won't have as many choices of weights.

5.5 mm spectra cord. be sure to leave a long enough tail on your double fishermans, it's slippery.

As Steve said - the largest that will fit. That will mean different sizes for different size hexes.

kiwiw wrote:5.5 mm spectra cord. be sure to leave a long enough tail on your double fishermans, it's slippery.

The "slippery" is important -- that knot will hang around for a while, but when it catches you, it is gonna take a beating.

For any slippery static cord, all you have to do is tie a triple fisherman's knot (don't forget the tail) and that will keep you.

If you can dig up an old Chouinard Equipment catalog it gives the exact diameter. The diameter they give will at first not fit but when you work it awhile it finally goes through. So the statement "the largest that fits" is not exactly true. It's the size larger than the size that goes through.

Also, I think Spectra is not safe. It's too slippery. Check that out carefully. My understanding that is very strong but that knots will pull out under heavy load.

I've used Kevlar on some of the smaller nuts and stoppers. It's super strong. It stiffens up after a short time which is good for reaching placements deep in cracks, but looses the runner effect of softer material.

I've a full rack of soft slung Chouinard nuts from the 1970s. They've been reslung 3 times since then but I retired it about 10 years ago. Now I just use camming devices and stoppers. I sure miss the sound of the old cow-bells though.

If you want to use spectra, then triple fisherman's for sure. I tried it, and wasn't happy with the result. It's too stiff--they're more likely to jiggle out of a placement. You also need to leave long tails, which just get in the way.

In my experience, the cord diameter Chouinard recommended was sometime ridiculously tight. After some time I just gave up, because the marginal gain in strength going from a 7mm to an 8mm cord (for example) just wasn't worth the hour or so it took me to work the fatter cord through those two holes (4 in the big hexes). So, "largest that will fit within reason" is still what I think makes sense.

I'm with the non spectra crowd. The stuff is stiff and slippery - handles poorly and doesn't tie well.

A good trick for the larger sizes is to arrange the knot so it ends up inside the nut when you pull everything tight.