The Slipstream (スリップストリーム,Surippusutorīmu?), also called Turbulence, is a gimmick that appears in allthreegames in the Sonic Riders series. It is a region of moving air created by high-speed Extreme Gear racing that other racers can ride on.
Slipstreams are regions of fast-moving air that takes the form of a long half pipe, essentially forming a road of wind, that follows the path of the Extreme Gear that created it.
In gameplay, racers can surf on the trails of the slipstreams like a track by either approaching it from the rear or push into from the side. While surfing on the slipstreams, the racers can in some cases accelerate on their Extreme Gear or perform Air Tricks. The slipstreams are only temporarily, however, and will eventually fade away.
Sonic Riders series
The slipstream mechanic first appeared in Sonic Riders where it is named Turbulence. In this game, Turbulences are sometimes created in the wake of racers riding Extreme Gear at high speed. However, Turbulence trails are not always formed in the same shape of the route the racer who created it took; in some parts of the courses, Turbulence is formed in the same position every time, and is created after a racer passes that area.
When riding on Turbulence trails, the player automatically moves at a steady speed without consuming Air and can move the control stick left and right to accelerate. If the player can reach the source of the Turbulence, they can overtake the leading opponent. However, the leading racer(s) can interrupt their Turbulence by jumping from a ramp, Air Ride, or grinding.
Depending on the conditions, Trick Areas can appear in the Turbulence. If the player's positioning is correct when these Trick Areas appear, the player will automatically perform Trick Actions while riding on the Turbulence to gain both Air and speed.
The player can press both shoulder buttons at the same time to break out of the Turbulence. There are also Turbulence sections in Babylon Garden and Sky Road which function the same as the general Turbulence trails aside it from being a fixed path and players cannot break out of them.
Sonic Riders: Zero Gravity
This mechanic reappeared in Sonic Riders: Zero Gravity where it was renamed slipstream. In this game, it only appears when the leading participants in a race make a curve.
The slipstream retains many of its mechanics from the previous title. Like in Sonic Riders, the player can ride the slipstream path at a steady pace for the purpose of launching themselves into the air to perform Tricks. Unlike Sonic Riders, the player must manually perform Tricks. This also allows the player to access shortcuts, including Wall Routes using Gravity Control and Air Ride-specific sections.
In addition to regular usage, riders racing on Yacht type Extreme Gear can automatically ride on slipstreams and accelerate on them while riding directly behind an opponent, which is otherwise known as "drafting".
There is also a slipstream section when racing down a slope at the beginning of Gigan Rocks.
Sonic Free Riders
The slipstream mechanic reappears in Sonic Free Riders where only Extreme Gear equipped with the Gear Part "Rapid Stream" are able to automatically ride on slipstreams and accelerate while riding behind an opponent. It works similarly to the Yacht type Extreme Gear's ability in Sonic Riders: Zero Gravity.