Our greyound, Bubbles, used to love bike rides in her trailer. The longest one we did was a camping trip of several days along the Devon Coast-to-Coast and she was fine; I found a child trailer that had a metal base rather than a canvas one, took the seat out and the dog curled up very happily on a suitably sized bed. It seemed important to be able to zip her in so that any sheep we might pass didn't get terrified. Bubbles died a couple of years ago but the trailer is still in the garage. I'm in Redhill, Surrey, if you'd like to try the trailer.