It seems there's two schools to this approach:

1. Say hi, possibly making small talk, and give help if asked.

2. Immediately say "do you need help" and if it is refused, ride on.

Self reliance is something to be applauded. That said, most bicyclist behave worse than pedestrians regarding general courtesy and friendliness. Motorcyclist, on the other hand, seem to all belong to a 'secret club' because they always wave and seem friendly (to other motorcyclists). Bicyclist (unless they are young and/or female) tuck their heads in ambivalence.