This is certainly the first I've heard of the idea that Spectra is more static than Dyneema.
Spectra and Dyneema are two trademarked brandings of the same material, which also has two generic names: HMPE (high modulus polyethylene) and UHWMPE (ultra-high molecular weight polyethylene). Since Spectra and Dyneema are the same material, it seems unlikely that one would be stretchier than the other. Since the fibers are produced by different manufacturers, I suppose there could be a difference in the production process that would yield a slight difference, but I have not heard of one. Do you have data to support the idea that HMPE/UHWMPE called Spectra is stretchier than HMPE/UHWMPE called Dyneema?
The Ultra Tech cord is made of Technora, which might be even more static than Dyneema/Spectra. (It doesn't matter though--once you get as static as Spectra/Dyneema, I doubt there's any benefit to going more static in a footloop. The amount of energy from your climbing step going into stretching the footloop should be insignificant with Spectra/Dyneema.) Unfortunately, Technora is slightly heavier!
(If I had Technora cord of the right diameter and needed to make a footloop, I would use it for that purpose without hesitation.)
PeterFJohnson wrote:Both are available in the US as they are made by US companies. There are other ones too I am sure. I know the Bluewater is 5.5mm so it might not fit in the Basic's smaller hole. They also sell a pre made adjustable foot loop assembly using 5mm titan. It is under "accessories" on their website.
Can you provide a link to the 5 mm Titan footloop assembly? I'm looking at
accessories and
accessory cords and I'm not finding it on either page.
Unfortunately the BlueWater Ropes website it set up so that the URL in your browser's address bar does not normally change as you navigate to different parts of the site. But if you right-click (or Control-click, on macs with one-button mice) on a link and open it in a new tab or a new window, then the new tab or window should show the correct URL of the page it contains.
I'm particularly interested to know the actual diameter of the Titan cord (which is a combination of Dyneema and nylon, and should be about as static as Dyneema by itself) in the footloop assembly. As you've alluded to, Titan cord with "5 mm" in its name is actually 5.5 mm in diameter (explained
here).