Quadbike Time Trials

The Quadbike Time Trials are a set of side missions available in Grand Theft Auto: Vice City Stories. They're available from the beginning of the game by riding a Quad parked around the dirtbike tracks in Downtown Vice City. This side missions substitute the Trial By Dirt sub-mission that used to take part here in GTA Vice City.

These missions are required for Completion in GTA Vice City Stories 100% Completion of the game.

The side mission consists in four courses, that get unlocked as you progressively beat each of them. The objective is to finish a 3-lap race within a time limit by hitting the checkpoints spread around the dirt-track. The minimum time limit is around 1:10 to 1:25 minutes.

Rewards
Completing the four courses, will grant you $ 2500. You can keep playing this mission once you've completed it. Each time you beat your time record, you receive a higher prize (in money).