Gear Part

Gear Parts (ギアパツ) are a type of gimmick that serve as an important game mechanic in Sonic Riders: Zero Gravity and Sonic Free Riders. They are performance-enhancing technological modifications to Extreme Gear which grants the player special abilities during a race.

Description
Gear Parts are performance-enhancing components that can be installed into Extreme Gears. When activated, the Gear Parts provides the user of the Extreme Gear with various abilities and/or upgrades during a race, ranging from upgrading the Extreme Gear's basic attributes to granting additional abilities such as the ability to grind on rails. In gameplay, this allows the players to gain extra advantages during a race, such as giving them a boost in their stats, allowing more efficient traversing of the tracks or even influencing the contents of Item Boxes.

Sonic Riders: Zero Gravity
The Gear Parts made their first appearance in Sonic Riders: Zero Gravity. In this game, Gear Parts come as components pre-installed into the Extreme Gears available in the game. Each Extreme Gear can have a maximum of three Gear Parts and no Gear Parts at all as a minimum. For those Extreme Gears with Gear Parts, they possess a permanent set of specific Gear Parts, meaning that their Gear Parts cannot be exchanged with others.

In gameplay, while in a race, the Gear Parts will remain inactive until the player acquires and trades a specific number of Rings to activate each of those Gear Parts, with each Gear Part requiring a certain number of Rings. When activating a Gear Part through a process called "Gear Change", the Extreme Gear is covered in an orange-colored void indicating that the Extreme Gear is modified with that Gear Part coming into effect.

As long as the player has enough Rings to activate a desired Gear Part, the player can activate any Gear Part on the Extreme Gear. That means that the player does not need to activate the Gear Parts in the order of which they become active, but can choose to not use the Rings on the available Gear Part and save up Rings until the desired Gear Part becomes active. However, some Gear Parts may require both a number of Rings and that a previous Gear Part has been activated beforehand, before they can be activated as well.

To activate a Gear Part in gameplay, the player has to press the following buttons:

Sonic Free Riders
The concept of Gear Parts return in Sonic Free Riders, exclusively for the Xbox 360 Kinect, but with different gameplay mechanisms. Unlike in Sonic Riders: Zero Gravity, the Gear Parts are separate from the Extreme Gears and the player can equip any Gear Part to any Extreme Gear, as opposed to having specific Gear Parts pre-installed into the Extreme Gear, allowing a larger range of abilities that an Extreme Gear can possess during a race. The player is required to spend Rings in the shop to acquire more Gear Parts in addition with purchasing Extreme Gear.

Most Board-type Extreme Gear can be equipped up to two Gear Parts of any type while most Bike type Extreme Gear can only be equipped with one Gear Part. All Bike-type Extreme Gears, however, cannot be equipped with the "Power Skill", since all Bike-type Gears come with the default ability of the Power Skill.

While racing on a Board-type Gear, only one Gear Part is active at a time. The player's stance when playing the game is what determines which Gear Part is currently in effect. By switching the player's current stance (by facing in the opposite direction), the player can activate the other Gear Part equipped to the Extreme Gear, while deactivating the current Gear Part.

Trivia

 * In Sonic Riders: Zero Gravity, most characters tend to say "Gear Change" when activating a Gear Part. On a similar note, most characters in Sonic Free Riders tend to say "Switch" when switching stances to activate the other Gear Part.