Tell me about using a water bladder in a frame bag for day touring.

bungle73 Posts: 758
edited May 2018 in Tour & expedition
Seems a lot of people do this, and I was considering doing myself, instead of using the standard rucksack arrangement. Are there any downsides? I had thought that since the bladder is on its side, rather than vertical, as designed, there is going to be point where there is still plenty of water, but it doesn't reach the hose exit so you can't drink it. Is this the case?

Also, I'm looking for a frame bag that comes with a shoulder strap, but there doesn't appear to be much choice. I'm currently looking at one from Lotus. The idea is that I need to be able to lock the bike up, and take everything with me while I visit an attraction or something. Obviously a standard frame bag with no way of carrying it for an extended period would be no good to me