This strange device was presumably discovered (but not revealed) by Jak and Daxter in Gol and Maia's Citadel at the end of Jak and Daxter: The Precursor Legacy, originally of unknown origin. However, it is later revealed to be built by Keira after her arrival in Haven City. In the beginning of Jak II, Jak activates the Rift Gate by pressing a red button on the Rider, which they brought to Sandover between the games. By doing this, the Metal Heads are unleashed into the world and Metal Kor is first seen coming out of the Gate. Jak, Daxter, Keira and Samos then use it to travel through the Rift Ring into the future. Then at the end of the game, it transports Young Jak and Young Samos to the past. Since the Rift Gate was the last one and was destroyed due to damage shortly before its final use, any remaining ones no longer exist.
The Rift Rider requires the Heart of Mar, found in the Sewers but acquired from Krew and the Time Map, found in Hip Hog Heaven Saloon in the Metal Bash game in order to function. Keira bases the Rider on her memory of the one she saw and built it out of various precursor artifacts, this means that the rider really has no original designer due to a stable time loop.
Presumably the Precursors have something similar for when they time travel.
The Rift Rider built by Keira in Jak II is based on the Rift Rider found in the end of TPL, and that Keira herself rode in the beggining of Jak II. Yet, Samos allegates that the Rider built by Keira would work perfectly fine, as it was the same one they found later (Samos and Young Jak travelled back in time to Sandover Village, and then hide the Rider and the Gate). This means that Keira built the Rider based on itself, which would be a Time Paradox.
- The Rift Rider makes a re-appearance in PlayStation All-Stars Battle Royale as a prop in the Sandover Village stage.