Air

Air is a special type of fuel used by Extreme Gear exclusively in Sonic Riders and Sonic Free Riders.

Description
Air was slowly consumed over by just accelerating and once the rider's Air gauge is depleted, the rider would be forced to run the track on-foot until he/she arrived at a Refill Station to replenish the Air, allowing the rider to ride on his/her Extreme Gear again (this was dropped in Sonic Free Riders which the player will still remain riding on their Gear).

Besides Refill Stations, there are many ways riders can earn Air:
 * The rider can perform Air Tricks when lauched from a ramp. The amount of Air earned varies on the rank of the performed trick: the higher the rating, the more Air earned.
 * Using character skill actions (grinding on grind sections, "air riding" (in which the rider flies through the air through dash rings that will give him/her a boost of speed) and the ability to smash through obstacles and barricaded paths without slowing down) also fills the Air gauge.
 * Collecting 30 and 60 Rings in which refills and increases the capacity of the Air Gauge.
 * One of the power-up items that can be obtained from Item Boxes can replenish Air.

Other actions that use Air include speed boosting (called "Kick Dashes" in Sonic Free Riders) which burns a lot of Air and thus it should be performed sparingly and slide-drifting through sharp turns (does not appear in Sonic Free Riders). While the rider crouches down before performing an Air Trick, this action consumes a slight amount of Air but enables the rider to access higher route shortcuts when the trick is performed.

Different types of Extreme Gears have different Air consumption/accumulation rates. Compared to the average Board Gears (which have an average Air consumption rate), Skate Gears are more fuel-efficient while Bike Gears burn around a double amount. Some Extreme Gears' abilities can also affect the consumption/accumulation rate.

Two special Extreme Gears, Chaos Emerald and The Crazy do not use Air but rather uses Rings as a replacement fuel that shares similar properties with Air.