Originally Posted by
Booger1
1" poly webbing and 2 d-rings.Cost $1,won't stretch when wet,hang your car with it,doesn't come loose,you can make them any size you want,uv doesn't bother it like nylon,lasts a lifetime.
Half right. Polypropylene and polyethylene don't stretch when wet. But they do undergo photo-degradation just as nylon does. The amount of degradation depends on many factors including length of exposure, treatments applied at manufacturing, presence of ozone, etc.
Originally Posted by
LeeG
not really but I know what you're talking about. Most of the tie down webbing that connects to fasteks are polypropelene or dacron and it does deteriorate eventually. The problem with Fastek buckles is that they really aren't mean to carry lots of force or cyclical forces. They work best as quick release and quick connect with working loads a lot less than the working load of the webbing. So a boat cover with 1/2" fastek gets connected and pulled TIGHT and then the weight of the wind hits repeatedly it or the next time the buckle is clipped and a 200lb person pulls HARD it breaks. For use connecting to racks or belts I don't see a problem but for applications where a load cycles or is very high it doesn't last. Like the 1" webbing and buckles used to suspend a 65lb kayak with static load it's no problem but if the load varies from 20-65lbs it can lead to failure. On kayaks they're used a lot to clip across hard shell hatch covers but if a person grabs the kayak by the strap it can snap.
I'd use fastek buckles to hold things on bicycle racks but if the bags were hanging down where weight was cycling on the straps I'd want some kind of backup if the buckles were narrow 1/2" size. Somehow I broke one of the tangs on the fastek buckle that straps over the top of my Ortlieb roller pannier. I jammed it in wrong and it broke. Surprised me.
Be careful not to think that all material properties are the same. Just because it's a 'plastic' doesn't mean that they are all the same. Polypropylene is very different from Dacron (aka PET, same material as in plastic pop bottles) which is different from nylon. Even all nylons...or polyamides...are not all the same. Nylon 6 is different from Nylon 66 which is very different from Nylon 5,10. Each one has unique properties and uses. Nylon 6 and Nylon 66 are the most common forms.
Originally Posted by
NeilGunton
Nope. I think there's a danger of overthinking this one - nylon (or whatever they turn out to be made of) straps work fine, you can tighten them down and they don't stretch at all (as far as I can tell, from a 5,000+ mile coast-to-coast tour in 1998 and another one in 2003 across Minnesota). My straps still look as good as new, in fact, no sign of damage at all (maybe a little faded from the sun), and as Pete said, they are only a couple of bucks a pop. They are better than bungees, in my mind, because bungees stretch - so if you go over a bump, the sudden acceleration of the load can make things move around and even dislodge and fall off the bike without you knowing. A webbing strap is tightened down, and it stays tightened down (in my experience). Also, there's that whole taking-your-eye-out thing. I've had bungees snap up unexpectedly and almost cause me permanent and serious damage, so I don't trust them now (at least, not for high-stress applications like keeping a load secure).
If your straps didn't stretch when wet they weren't Nylon 6 or Nylon 66. Both of those very common nylon formulations absolutely do stretch when wet. A 12" nylon 6 strap would stretch to 18" when wet. It certainly could make a huge difference while binding a load on a bike.
If your straps, nylon or polypro, are faded, they have been damaged. Fading is the first indication of photodamage. You may not lose a lot of strength but don't be fooled into thinking that fading is nothing to worry about.
I understand the issue about bungees flying off when you release them. That's one of the reasons I switched to the ball bungee. I use 4 and when I release them, the spring away from me rather than towards me. There are no hooks on them to catch anything nor to dig holes in the bags.