I am planning on going on a long distance cycle tour, but for some sections, I will put my bike on public transport. Does anyone have any general advice for putting bikes on public transport in Europe and beyond. I have limited experience with this and I am worried about possible charges, or being refused.
According the general conditions of eurolines (more or less the only paneuropean bus company bicycles are not allowed:
With trains it might be a different story.
The belgian railways have an informative page on international biking + rail
Terms and conditions concerning carriage of bicycles
Could't find conditions in English, but found a nice blog
For the remaining European Countries, I lack the language skills to find proper information on trains on bicycles. There are tons of blogs where people describe their journey in a specific country, that might help you. Google is your friend here.
Transporting your bicycle yourself
A different alternative is to cycle all the way yourself. There is a huge network of cycle friendly paths, often going to the more scenic routes in Europe.
In the Netherlands there is a foundation called "vrienden op de fiets" (friends on the bicycle), which annually publishes a list of accomodation addresses specifically catering cyclists. Although it is centered to the netherlands, their network do cover other countries as well. With these kind of informal networks, you can cover quite some miles and not be alone while doing so. Also people you meet in these accomodation types are often quite knowledgeable on local bicycle information and might know for example specific chartered bicycle bus services, that do exist in Europe.
Normally buses are very crowded in most European cities and while might be allowed would not be practical. Maybe long distance buses where the luggage goes beneath would allow it since it could be considered luggage. Netherlands is the most bike friendly place in te world and a lot of people there take bike vacations in Europe. You might want to check with the ANWB Dutch travel organization for suggestions of routes and trips.