Racing Telemetry Glossary
Every technical term used in track riding and data analysis, explained clearly.
Driving Techniques
Late Apex
A cornering technique where the rider/driver delays turning toward the inside of the corner until later than geometric center. This allows for earlier throttle application and better exit speed, sacrificing some entry speed.
Early Apex
Turning toward the inside of the corner too soon, before the optimal point. Often results in running wide on exit or having to reduce throttle mid-corner.
Trail Braking
Gradually releasing brake pressure while turning into a corner, rather than completing all braking before turn-in. Helps rotate the vehicle and maintain front tire grip through corner entry.
Throttle Blip
A quick burst of throttle during downshifting to match engine RPM with wheel speed, preventing rear wheel lock-up and chassis instability.
Body Positioning
The technique of shifting body weight on the motorcycle to optimize grip and lean angle. Includes hanging off, positioning knee and elbow, and keeping the head low.
Counter-steering
The technique of briefly pushing the handlebar in the opposite direction of the intended turn to initiate lean. Push left to go left, push right to go right.
Weight Transfer
The shift of vehicle mass from one end to another during acceleration (rear) or braking (front). Managing weight transfer is crucial for maintaining grip.
Rolling On Throttle
Smoothly and progressively applying throttle as you exit a corner, rather than snapping it open. Prevents wheelspin and maintains traction.
Coasting
The transition phase between braking and throttle application where the rider applies neither brake nor throttle. In telemetry, excessive coasting indicates lost time — fast riders minimize this phase by transitioning directly from braking to acceleration.
Metrics & Data
Friction Circle
A visual representation of combined tire grip showing how lateral (cornering) and longitudinal (acceleration/braking) forces share the available tire grip. Optimal driving uses the full circle.
Consistency %
A measure of how consistent your lap times are, calculated from the standard deviation of valid laps. Higher consistency (lower deviation) indicates more repeatable driving.
Lean Angle
The angle at which the motorcycle is tilted from vertical while cornering, measured in degrees. Higher lean angles allow faster cornering but require more grip.
Sector Time
The time taken to complete a specific portion of the track. Tracks are divided into sectors to help identify which parts of the circuit need improvement.
Minimum Corner Speed
The lowest speed reached during a corner, typically at or near the apex. Critical for karts where acceleration is limited — carrying more speed = faster laps.
G-Force
A measure of acceleration relative to Earth's gravity. 1G = 9.8 m/s². Used to measure braking force (decel G), acceleration (accel G), and cornering force (lateral G).
Equipment
Slipper Clutch
A clutch that allows some slip during aggressive downshifting, preventing rear wheel lock-up from engine braking. Reduces the need for perfect throttle blipping.
Quickshifter
An electronic system that allows clutchless upshifts (and sometimes downshifts) by briefly cutting ignition or fuel during gear changes.
Traction Control
An electronic system that detects and reduces wheelspin by cutting power or applying brake. TC level settings trade off between safety (high) and performance/feel (low).
ABS (Anti-lock Braking System)
An electronic system that prevents wheel lock-up during braking by modulating brake pressure. Track-oriented ABS allows more wheel slip before intervention.
Track Conditions
Marbles
Small pieces of rubber that accumulate off the racing line from tire wear. Riding over marbles significantly reduces grip and can cause crashes.
Green Track
A track surface with low grip, typically at the start of a session before rubber has been laid down. Requires more caution and gradual tire warm-up.
Rubbered In
A track surface with good grip because rubber from tires has been deposited on the racing line through use. Grip improves as the day progresses.
Highside
A violent crash where the rear tire loses grip then suddenly regains it, catapulting the rider over the high side of the motorcycle. Often caused by aggressive throttle while leaned.
Lowside
A crash where the front or rear tire loses grip and slides out, causing the motorcycle to fall toward the inside of the corner. Generally less violent than a highside.
Want to go deeper? Read our article Racing Telemetry Vocabulary: 25 Terms Every Track Rider Should Know