I just got this bag from Amazon in the medium size and I freakin love it. I got it with biking in mind as well. It swings around easily and could be used effortlessly while riding to access everything you need from the side compartments. It breaths well, fits very nicely, spreads out the weight, and secures well with the chest and waist straps to keep it from bouncing around. It also has a weather hood and a flat bottom for when you stop.
I'd wear this on a dirtbike and motorcycle without a worry.
How well does it fit your D7000? Right now I'm storing it in my Panniers (interesting etymology), but I'd like quick access, so a sling bag doesn't sound too bad.
I fit the D7k in there perfectly. Currently in the bag:
-D7k with 70-200 attached (have about 2 inches of room left with this lens on the far side, if you have a bigger lens)
-18-105 with hood & caps
-Charger and extra batteries
-Filters (1 in its own (large) plastic case and 4 others in another case)
-Cleaning cloths
-Weather hood
-USB cable
-USB SD card adapter
-2 extra SD cards and a micro SD card adapter
-Tripod mount
-Lens/Body caps
-Remote and extra battery
-GoPro HD 2
-GoPro suction cup mount
-GoPro 3M mounts
-Second GoPro body and backer
I could fit another lens in there and a ton of other stuff if I wanted. I had my lunch for work (2 sandwiches, a banana, waterbottle, snack) in the top pocket as well. There are so many little compartments it's hard NOT to be organized.
The padding is excellent, and the velcro that holds the dividers is seriously strong. It took me about 10 mins to set it up the way I wanted but it's very customizable and there's room for everything.
I used to do DH biking, and I frequent trails on a dirtbike when back in NJ. I wouldn't sweat for a second that my gear would be ok in this bag in those conditions.