Cycling to work is undeniably a good thing. Sweat on the other hand, is not. My commute is 7.5 miles, a lot of which is uphill. Riding a bike with a backpack full of stuff makes me sweat quite badly and my work doesn't have any sort of showering facilities. Couple that with being required to wear a shirt and tie and you have a recipe for disaster.
My bike has a pannier rack on it so the natural idea is to put a pannier bag or two on. This however would mean transferring stuff between the pannier bag(s) and my EDC backpack irritatingly often and means having extra kit about the place.
The solution then is to put the backpack itself on the bike. A few options were brainstormed. Ratchet straps were tried but ended up being more hassle than they are worth. Using a Greyman Tactical RIP-M panel was attempted but unsatisfactory. What is needed is a way of hooking the backpack straps to the rack.
Way back in the day, I got a Kifaru Paratarp with the peg and pole kit. The kit has basically been retired, got better pegs and hiking poles for that purpose but I kept the poles around for future use. I attached one of the pole segments (basically a bit of aluminium pipe) to the rack with a couple of hose clamps and used a couple pieces of kydex from a previous project to space it out. Hook the straps over the pipe and tighten them down and the bag is securely attached to the bike. Doesn't move an inch.
The major downside to this approach is at low speeds (namely moving off and manoeuvring on foot) the bike is biased to one side which is interesting getting it down the hall at 04:30. At regular cruising speed I don't notice a thing.