E-10000R (called Robo 1 on the official American website) is a character in Sonic Riders. It is a red robot built by Dr. Eggman for speed. E-10000R's unique Extreme Gear is called E-gearR, and it can be unlocked as a playable character after fifty hours of gameplay.
Right before the Egg Factory race of the Heroes Story Mode, E-10000R accidentally walks into a fight between Knuckles and Storm right after it gets confused about Storm's Extreme Gear, the Type-S. It gets severely damaged when Knuckles accidentally punches it from behind. When Storm tries to give Knuckles a REAL punch, he punches E-10000R, causing him to malfunction and shut down. It would possibly explain why it wasn't in the Egg Factory race, why he was late, and why he didn't make it into the rest of the Tournament. In the Babylon Story Mode, it was repaired and it tried to capture the heroes with a gang of E-10000Gs. During this confrontation, it had visible damage from the earlier battle, indicating it was probably the same robot. It still chased them in the Sky Road race, but they eventually got away.
According to the official Japanese Sonic Riders website, E-10000R is equipped with the same kind of engine as Metal Sonic.
E-10000R has the ability to split its head from its body to scare/strike opponents or simply attack them with its large fists.
In Story Mode, he sounds just like the other E-10000Gs, but when playing as him after unlocking him, his voice sounds a little higher-pitched.
Like all the other robots from the E-Series, this one has other robots that look similar to it, but in different colors. For example, E-10000G is the clone of E-10000R, but in the color green rather then red. Also, there are two other robots in the Egg Factory course that appear to be yellow or purple clones of E-10000R.