The rider transfer season typically starts halfway through the year, especially during the Tour de France when many contracts are agreed upon for the following year.
http://us.rd.yahoo.com/dailynews/rss/search/tour+de+france/SIG=120bid83c/*http%3A//www.cyclingnews.com/road/2004/transfers04/?id=default
http://us.rd.yahoo.com/dailynews/rss/search/tour+de+france/SIG=120bid83c/*http%3A//www.cyclingnews.com/road/2004/transfers04/?id=default