Federal authorities are investigating the theft of two bicycles belonging to Olympic gold medalist Kristin Armstrong. The bikes were stolen at some point while being shipped to Boise from Germany, where they had been on display at an event. Armstrong’s gold medal time trial bike is worth nearly $30,000 and her road bike is valued at almost that much. U.S. Immigration and Customs Enforcement said Wednesday agents in the United States and Germany were investigating the theft. Armstrong said the time trial bike symbolizes of all her hard work and she’s sad that somebody took that away from her family. The bikes were shipped from Germany on Sept. 7 and made stops in Frankfurt and Atlanta, but only empty boxes arrived at Armstrong’s house Tuesday.