At least one key area missing - the opposite sex - after every stage you hear about who saw such and such a girl and where.
A "well known pro" once screamed into the pits in a crit, just to send the mechanic off to secure a date from a young woman watching - it worked as well!
Cars also feature quite a lot in my experience as well, most pros seem to read car mags rather than cycling ones - lots of lusting after after desirable ones.
On a stage race there is usually lots of time for banter and fun before the battle starts - especially in Italy.
It's not unusual for a rider to come back to the team car just to relay a joke they have just heard (maybe they use the radios now; my experience is pre-radio)