+1 for the above. Plus anything strapped around your torso, tends to restrict movement, that tends to be more vital in actually controlling a motorbike....
And why would you need a holster type camera bag when on a motorbike, it's not like.your going to take it out and start shooting pictures whilst you are riding, is....
Ah!...
do as I say, not as I do!!!!!
Actually, that was taken 'blind' under my arm with an Olympus XA2 'film' compact, one handed! A well practiced hand at that, using the diddy little thing, well suited to one handed operation like that, in such a manner from sliding down a snow covered hill on planks of wood in my teens, through to chasing tear-away tots around a playground in my thirties, to well, you get the idea. I DONT think I would contemplate such antics with a Digital SLR! Thogh I do know of some folk who have a penchant for 'Point-of-View' action shots from the saddle, and one of the uses a sort of parachute harness with a tripod mount on it, and a remote release cable gaffer taped to his handle-bar I think! NOT the sort of stuff that would get the BMF seal of safety approval, though, I think
Back on topic!
As Brad & Byker suggest, you can get tank-bags that clip to the petrol tank when riding, which gives you least weight to carry r shift on your body when ridng, and no restriction of movement, or risk of possible injury from luggage slidng up the road with you if you tumble....probably as or easier to grab a camera out of a tank-bag on the tank,..... when you STOP... than to ferret out of a holster bag.and most 'convert' som-how nto a shoulder bag or ruck-sack when removed from the bike.
Mine has 'wings on the sides that have magnets to hold the bag on the tank when riding, and clips to clip the rings under the soft-base, and convert it to a shoulder bag, when off it. Its a rather old now, err. circa 1993! Oxfort 'life-time' two tier.. that bag's probably done more miles than my bike! Dang useful bit of kit!
I used to work in a factory that made electron'c control systems for aircraft, and we used to have 'pizza-boxes' that assemblies were shipped out to or back from the customer, for repair/investigation/modification,that had the same sort of segmented foam packing in them as a photo flight case, that used to be 'scrapped' if the out side box was damaged.... this of course gave me an
oy-dee-ugh! When I came accross a pile of scrap shipping boxes i the corner of the dispatch room, and that Oxford Tank-Bag was at one point, compartment-ed with the foam packing salvaged from such scrap freight boxes, for my SLR's... s much as anything to stop the heavy camera denting my chuffng petrol tank when I went over a council speed-bump, as to protect the camera!!! But still! injinuity eventually saw me stuff the tank-bag with a thick woolly jumper and spare water-proofs for multiplicity, but still.....
Ultimately, these days the SLR tends to live in its regular shoulder bag, which gets attached to the rear luggage rack, along with other camping apparel, or used as ballast in the bottom of one of the panniers, rather than any 'special' measure given to it, whilst that XA2 film camera tends to live in my jacket pocket for grab shots....and the handlebars have a mount for an action-cam, and the daughter hangs off the back snapping away with a smufone... and and and......
Options and alternatives are myriad, BUT... a holster type camera bag for a DSLR REALLY isn't top choice....