All the cameras mentioned by other colleagues are not DSLRs. They are either analog SLRs or mirrorless compact cameras. DSLRs are very susceptible to vibrations especially those that can be encountered on a moving bicycle that hits all sorts of bumps on its way. DSLRs have sensitive mirror and focusing sensors located around it which can get out of alignment. I'd pack it in a professional case if I can find one. Otherwise, it would always be in a camera bag on my back. I carried it like that and it was fine. I have rather expensive camera, several times more expensive than my bicycle. I might risk with the bag on my handlebars, but I'd not put it somewhere at the rear rack without very good protection. All in all I am also very interested to learn how to tour with my DSLR because I avoided that risk before unless it was in a bag on my back.