Rowan

I've ridden more than once or twice in Amsterdam, and the km/h speed you nominated is almost unknown, except for serious road riders outside the city who aren't being treated badly by drivers.

The types of bikes most obvious then for use in the city were heavy European types, or with strong linkage to mountain bikes. The high density of riders on (very few) roads and cycle pathways means quite a slow avenue.

For me, it was almost walking pace to get from the information centre to an exit from the city. The only speed about 20kkm/h for me as a fully loaded touring rider was from the ferry into the city on new path that was very similar to the ones shown in the thread's first post... with very few users.

Yes, it was tourism times, but again through observation, there were a bunch of people whose only interest seemed to be in how they could, and how much drugs, they could source. Oh, and of course, grabbing a view of the prostitution part of the city, that is promoted pretty quite heavily.

My riding in other parts of the country was much better, and generally much friendlier.