I don't like to wear a backpack while riding. Never did. Uncomfortable, and the thought of an unplanned dismount with it strapped to my back is unpleasant...
You don't say what kind of bike.
My ST has the bags removed. If I am going to carry stuff that doesn't need the room the bags would provide, I leave them off and just use a Cortech sport tail bag
http://www.kneedraggers.com/details/...g--609956.html. I leave the camera and lenses separated, places them in zip lock bags and wrap then in a towel. Never an issue. I have a Canon 1D MK2 which is a large heavy camera and f/2.8 (read also large & heavy) zooms. I admit that it is inconvenient to make that quick stop for a shot at a road-side scenic area because of the unpack and assemble required, but it does work out OK. I don’t carry a laptop, but the tail bag I am talking about expands side-to-side and looks as if it would carry one with no problem.
If you have a bike that would make it impractical to mount a tail bag, consider a tank bag. I really do not like the idea of a backpack while riding, but if it is your only option, there are many camera / computer backpacks on the market.
The other thing I’ll say is that I rarely do this at all. I only carry my camera if I am going to a place that I will be using it. Like tomorrow. I’m riding to an event that I will want to take pictures at, so I pack it. If I was going to carry a camera all the time while riding, I’d buy something like a Canon G10 and leave the DSLR and lenses at home.