The FastBack Double Century Hydration Pack straddles the back of your seat with one three-liter pack on either side. It's the solution for lowracers and other hard-shell bikes & trikes with limited tire clearance, as well as Bacchetta EuroMesh seats. Stow away a 3L CamelBak Hydration Bladder one side and use the other like a pannier to keep some gear. If you ride in the hottest parts of the planet, enjoy bike touring or want to ride and ride without having to stop for a refill, then the FastBack Double Century Hydration Pack is a must have!
The double century bag is great. I keep a 3L camelbak in one side and the other has my spare tube, pump, multi-tool, and these days: a spare covid mask for when I stop. I can unzip and access either side while riding, not that I need to often. Attachment was a little tricky on my Schlitter Encore, but the extra straps made it possible. The bags cling tight to the seat pan and don't wiggle around. A great bag, I'd buy one again for sure if I ever get another recumbent.
I bought this pack to solve my hydration issues for long rides on a Cruzbike Vendetta V20, and it is great. The pack is well built and the zippers are robust. It takes a little while to figure out how to install the pack, but once on, it stays put. It is low profile and I think has very little aero effect while providing quite a bit of storage space. I recommend this as a high quality bag that works as billed.
I have a set of these that I have used for 10 years. These are wonderful, they work very well with various bladders and I use the other side for tools, pump, wallet, keys etc. I have also used two bladders on events with one being water and the other being a nutrition mix of some sort (electrolytes or protein mix). If you search Duncan and Raptobike you will likely see images of these bags on my bike. For bikes with a hardshell seat I can't recommend these enough. I also used one side on my Bacchetta Corsa with EuroMesh seat, the double wasn't a good fit in that case as there was chain interference on my right side but the single was perfect. I have done double centuries with this multiple times and love my FastBack hydration packs. I am shopping for a new set soon as the straps have started to get cut through, that damage is from times I have crashed (in turns, potholes, etc) on the bike and not a fault in the gear. In fact the straps mitigated damage to my seat and myself.