Originally Posted by
cyccommute
The only problem with nylon straps is that nylon stretches when it gets wet...significantly. Make sure you adjust them if you get caught in the rain. Bungees don't have that problem.
I've had the (ahem...) pleasure of riding in all day, soaking rains a couple of times while touring. I've never noticed anything getting loose due to nylon stretch. They were cinched over some compressible items, like a tent and sleeping bag, so that might accommodate any wet nylon stretch. If things loosened in the rain, I'd merely stop, cinch things a bit tighter and move on. It won't keep getting looser.