G'Day Dave,
Welcome to IIS!
For motorcycle touring and astronomy you're really looking for small/compact and robust astro gear. My suggestions would be:
- 7x50 or 10x50 binoculars. If they are too big (I know what its like to pack a bike!
) go for similar magnifications in say 38mm. There are apparently some excellent image stabilised binos about the 10x38 size that are reputed to perform as well as larger binos because they are stabilised.
- If you must go for a scope, I like the spotting scope suggestion. In my experience they are generally more robust that an astro scope, but if it was me I think I'd stick to binos.
- Get a planisphere and a red light torch and maybe some star charts or a compact book like the "Collins Guide to Astronomy", or "Astronomy with Binoculars" which have charts in them.
Best place to carry a camera/DSLR IMHO is inside a padded camera pouch in a tank bag. The tank bag will not vibrate as much as panniers or a top box.
I would probably limit any astrophotography in these circumstances to startrails, or existing light landscapes with the camera on a fixed tripod.
Al.