Originally Posted by
mdilthey
I wouldn't dream of hiking in the Kompressor.
I've done it, and it's fine. So have plenty of other people. It's not an Osprey Stratos, but as an ultralight daypack, it fits the bill.
Channeled packs do reduce heat on the back, but not as much as you'd want if you're cycling with a backpack all day long. The weight will also be uncomfortable.
Try this: Take a backpack (I assume you have one), get it to the same weight you'd plan to bring on tour, and wear it for a 50-mile ride with some hills. Next, take the same amount of weight and put it on the rack, and do the same 50-mile ride. While you may find that the backpack is acceptable, I believe you'll find the rack option is a vast improvement.
Originally Posted by mdilthey
It's easy to say "one day" but if you're miserable with 14 pounds on your back for 5 hours, suddenly I'd wish I had brought something more than a dry-bag.
So you're OK with potentially being miserable for your entire trip, as opposed to having a warm back for a few hours...?
Originally Posted by mdilthey
I saw a warning on a photography forum that bike racks are subject to high-frequency vibration that can ruin cameras, in which case I'd absolutely wear a backpack (it's not THAT bad, it's just a backpack, you sweat anyways...). Has anyone heard anything to corroborate camera safety as a reason to use a bag?
To reiterate comments from your other thread: A handlebar bag with camera inserts is undoubtedly the superior option. Better protection, more convenient, better weight balance.
I wouldn't worry about "high-frequency vibrations." But I also would not put a valuable camera into a backpack that is jerry-rigged onto a bicycle rack.