I'm new to the board and bikepacking so I could use a little advice on my setup. A little background first: I consider mountain biking to be my primary sport, followed by backpacking. (why didn't I combine them sooner?!) My bike is a fully rigid 29er. My backpacking gear is down to about 8lbs carried excluding food and water. I have two questions:
I love the frame bag concept but I'd like to go a cheaper route using as much existing gear as possible. (simplification is king for me) It looks like I should be able to make a workable kit out of a 15L or 20L Sea To Summit dry bag strapped to a seatpost rack. Is any particular brand or model of seatpost rack recommended? I've found Zefal, Topeak and Delta. I don't have rack mounts on my frame so using a traditional rear rack would be difficult. Will I have issues with sway using a seatpost rack? Should I just bite the bullet and just get a frame bag?
I'd plan on getting the rest of my gear in a Camelbak Mule (bike maintenance gear, water filter, snacks, camera, etc). To save space in the dry bag I'm thinking I could strap my Thermarest PL3 short under or possibly around the top tube. For longer multi-day use I could always replace the Mule with my GoLite Ion for plenty of additional volume (~20L).
My bike computer is dead and needs to be replaced. I'm considering replacing it with an Edge 305, Edge 705 or Vista HCx. I'm leaning towards the 305 because its hard to justify the extra cost of the 705 for mapping and longer battery life. It looks like I can get a 305 for around $200 off of Craigslist. The HCx would be nicer for backpacking and kayaking but I don't really need one now. I'm thinking: why compromise for a unit that isn't focused on cycling? I do like that the Vista takes AA batteries. On a multi-day trip I'm not sure what I'd do to recharge the 305.
Thanks in advance for any advice.
As for the GPS, take a look at the Garmin Dakota series. Mapping, AA batteries, nice h-bar/stem mount, lots of memory and pretty rugged.
Seat bag and a frame bag are great ways to go.
+1 on the Talon 22 bag from Osprey.