On sunday mornings at 11 o'clock there's always a group of students riding on their roadbikes from 'Het Kalfje', a cafe a bit out of town next to the 'Amstel' river.
My girlfriend lives in Amsterdam but she's over at my place the next couple of weekends. If i'm in Amsterdam i'll let you know, maybe we can do a nice ride! Have you got a fixed or geared bike with you?