My cycling mentor, who is also a member of this board is 50+ and this guy is an animal. I'm 45 and it's all I can do to ride fast enough to keep this dude from getting bored.
This guy climbs big and little cottonwood canyons (for those of you that know about the Salt Lake Valley) on weekend for practice.
I would put him up against any recreational/jersey rider. IMHO 50+ simply means more experience and smarter riding.