I was comparing them to my Topeak fold-down panniers, not the Rockbros. The Topeak are well-made, but not heavy-duty. Regular zippers that would let heavy rain through and just treated nylon fabric. They're kind of a gusseted envelope shape, (for easy folding) instead of a proper box shape like proper panniers would be....
(re. waterproof and more durable) Nope. I didn't find them to be. The RockBros are truly solidly constructed, and there's no way water is getting inside once they are rolled up, same as an Ortlieb.
The way it slides on and off quickly and easily and latches sturdily in place. It's wonderful, very easy to bring in with me, nothing left on the bike that might be stolen. Bontrager has something similar, but it's more expensive, of course. Comes with a shoulder strap, so it's easily carried while out on foot too.(Re. Topeak MTX)
I can't imagine why anyone would buy a proprietary bag like that. So many better options for both the rack, rack trunk and panniers.
I use it about 70% of the time just as an expandable trunk bag; lunch box for work or a small item or two picked up at the grocery store on the way home. It's the right size for a 6-pack and about 5 oranges before being expanded. When my eyes are bigger than my trunk bag, I just fold a pannier out. Or when I need two bags + change worth of shopping, they're perfect, of course.
Thanks for the link. I'll save it in case I want something with external pockets and a bit more capacity, once I've tried these "rubber Ortliebs"....
I had a set of these (link below) and gave them to a friend. They were actually really good. Not convenient to take off the bike (at all) but if they remained a permanent resident on the bike, they were fifty bucks well spent.
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