Gothenburg (Sweden) has 50 bicycle stations spread through the center which works perfect for tourists. You can get a season(250 Swedish krones) or 3-day ticket(10 Swedish krones= €1,1). The bikes are removed during winter time (October 31st - April 1st). The city itself has many bike lanes which make it a nice place to bike. (But when I compare it to The Netherlands, my home country, it has some points of improvement.)
Sources: Short summary here and Official website