What made Joseba Beloki's back tyre rip apart from the rim on the 9th stage of the 2003 Tour?

Explanation

Joseba Beloki (born 1973) is a Spanish, former professional cyclist. He was a climber and started his professional career in 1998 as part of the Basque team Euskadi. Beloki came second in Tour de France 2002 and won Volta a Catalunya in 2001. On the 9th stage of Tour de France 2003, Beloki crashed descending Cote de la Rochette, because warm asphalt made his tyre rip apart from the rim. Lance Armstrong who was just behind had to divert into a small field. Beloki never regained his old form and stopped his career in 2006.