Two of us considering a bike tour (500 miles) including a 2x15 miles hiking section -- an overnighter with bikes left behind.

We'd be tempted to strap our Osprey Stratos 36L to our rear rack, but it appears to be next to impossible. We could ride with our backpack on our back, but that seems to be less than desirable. We could purchase frameless backpacks (such as Osprey Talon 33L) and stuff them inside a pannier when riding. I would not consider convertible panniers.

Our hiking involves carrying food, water, cooking and sleeping equipment. 2x30L pack is more than enough.

How would you do / have you done something like this?