Early on, Montgomery was considered to be a very promising rider. He turned professional in 1998 with the , with his career lasting until 2006. Throughout his career, he rode for several prestigious professional teams including , and . He was considered a climber. After finishing third in the 2000
Tour de l'Avenir, he won the fifth stage of the
Grand Prix du Midi libre and the mountains classification of the
Critérium du Dauphiné Libéré in 2001. He competed in four editions of the
Tour de France, but failed to finish any. Montgomery's career was overshadowed by bad luck. In 2001, during his best season, he was badly injured in a crash at the
Tour de France, where he suffered several serious injuries to the face and head, making him almost blind. This heavy fall prevented him from riding for almost the entire following year. During the
2004 Giro d'Italia, he suffered multiple injuries, including a tear of his scapula and a broken collarbone. In addition, he fell badly ill in 2002. Because of his numerous setbacks, Montgomery retired at the age of 30 in 2006. He then became a
directeur sportif for the , a professional women's team. ==Career achievements==