Well, the 48 & 50 yr old guys are still killing it out there. Maybe they're not TdF caliber, but they're still monsters compared to everyone else.
Tinker Juarez and Ned Overend still dropping the hammer on everyone - at ages 48 and 50. It seems also in Norcal, that the 50s guys are just as fast as the 30s guys. Not so true in running for whatever reason, but it seems the case in cycling.
http://velonews.competitor.com/2011/...um=most-viewed