For mass start races (group races) only drop bars are allowed. Period.
Standard road bar:
"Track" or "Sprint" bars are preferred by those who do race sprint events that involve a standing start in drop bars (like the Team Sprint) or slow rolling start (like Match Sprints). The curve of the bars immediately from the stem area allows the forearms to not get bruised. They also tend to like the low hand position which is only comfortable for a short time, but most sprint events are around 1 minute or less (except for the Keirin). Aerodynamics is key.
Most Madison riders prefer a bar with a flat area up top for gripping during exchanges.
Many mass start racers prefer standard road bars which don't drop so deep. Their races are much longer than sprint events, so comfort is a major factor.
Aerobars (bullhorn bars with or without extensions) are only allowed in individual or team time trial events.
They are not allowed in group races because they are a safety hazard. They could gore someone in a crash.
Originally Posted by gtrob
Roadies can run tempo all year as that's what humans were designed for. If you want to be a cheetah, lay around and lick your paws more.