Wait a minute! Was that picture there in your first post when I first saw this thread?
It's an Unbottle! Just got one myself. Is yours the 70 or 100 ounce size?* I got the 70.
I've had a cheap knockoff camelbak style thing for years. Actually it was just a bladder that I crammed into a neoprene sleeve with shoulder straps. I always hated wearing the thing - made it a real pain to take off the jacket. And it didn't insulate for squat. When I was packed for camping I just lashed it to the seatbag. As soon as I saw the unbottle I knew it was for me and I knew where I'd put it.
It's not fastened at all. It just slides in there and stays snug. Since it's right there where it would be if I were wearing it, the hose is already just the right length.
I wasn't all that worried about how I'd carry it without the seatbag, I just knew I'd come up with something, probably lashing it onto the tank bag somehow. On the July 4th weekend on a camping trip, I was making a beer run without the big bag when it came to me in a flash. When I got home, I took my jacket and the Camelbak to the seamstress and convinced her to try something crazy.
I got her to sew five loops onto the back of the jacket. Now it's like the thing is a part of the jacket and I don't have to remove it from the jacket to fill up. The nylon straps from the two top side loops extend up both sides and are angled to and sewn under the armor so all of the weight is carried up to the shoulders. The top loop is there just to keep it from flopping over limp when it isn't full and the two lower loops just keep it from flopping around in general.
I keep the bite valve handy with a Key-Bak. I got the kind with a nylon strap and carabiner** so it's easy to hang wherever. When it's stuck in the seat bag it hangs from a D-ring on the bag. When it's hanging up at the campsite working as the kitchen sink, it hangs from the Camelbak's own strap like in the picture above. When I'm wearing it the Key-Bak hangs from a D-ring on front of the jacket:
As for your mounting quandary, why don't you make up a couple of 1" nylon straps with loops on the end to hook into the two lower clips and sew magnets into the other ends? If the straps are long enough, they'll attach to each other behind the bag when you remove it so they won't dangle. If you get a tankbag later you can still mount it the same way since the longer straps would probably still reach down to the steel. That way it'll be easy to flop it over the dash or push it to the side for refueling.
*Your picture is so sharp I can tell, on second look, that it's a 70.
**The best price I found on that Key-Bak, by far, was at
Harbor Freight. Even with their high (IMO) shipping fee it was still half the price I saw in most places.
