Gothenburg (Sweden) has 50 bicycle stations spread through the center which worksare perfect for tourists. You can get a seasonseasonal (250 Swedish kronesSEK) or 3-day ticket (10 Swedish krones= €1,1SEK). You can even grab a bike for 30 minutes without paying anything. 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