These are beta elements in Sonic Riders: Wildfire.
Originally, the characters Espio, Amigo, Alex Kidd, and Typhoon were in Speed, Big, Omega, Hyphen, Billy Hatcher, and Aiai were in Power, and NiGHTS was in Fly. In the second version, Metal Sonic replaced all speed characters mentioned above, Vector, Bark, E-10000G, and E-10000B were in Power, replacing all power characters above, and Amarjeet and Super Sonic replaced NiGHTS. In the final version, E-10000B was taken out and replaced with E-10000R. Also, a purple E-10000 robot was going to appear in Fly, but was removed.