some do, some dont, i do this running thing which says its 6.5km but it never ends and i ended up doing 11km one day, i think its the half marathon tempo run.
but as above some bike races dont show the distance. This should be immediately after the name of the race, its not a massive issue as most of them do but i joined up for a race the other day thought it would be 15 - 30 k . . .ended up being 70!