Japan has several good bicycle museums. Below are three worth checking out.
Jitensha Bunka Center
Tozai subway line to Takebashi Station. Exit 1B, seven minute walk.
Tozai/Hanzomon subway line to Kudanshita Station. Exit 2B, seven minute walk.
600 yen for adults, 400 yen for children
Cycling Gallery Yagami Jitensha Shiryokan
Subway Sakuratori Line to Gokiso Station. Exit 4, 6 minute walk.
Open Saturdays, admission free.
South Of Osaka, in Sakai. Take the JR Hanwa Line to Mozu Station. A 10-minute walk.
300 yen for adults, 200 yen for junior high school students
This is the best of the bunch.