Lean angle glossary

Short definitions of the terms used across Krengo, each with a link to the page that explains it. Every definition repeats what those pages already say.

Lean angle

The frame’s sideways tilt from vertical. A number shown to one decimal place is display resolution, not proof of accuracy.Source: How to measure bike lean angle

Roll angle

The name of one orientation output from an IMU. It is not automatically frame lean: check the sensor’s axis mapping and mounting first.Source: DIY lean-angle logger

Road camber

The slope of the road surface. It is a different thing from lean angle, and it changes how much pedal clearance you really have.Source: How far can a road bike lean?

Combined centre of mass

In the physics model, lean is the tilt of the line from the tyre contacts to the centre of mass of bike and rider together. It need not equal frame lean when the rider leans separately.Source: How far can a road bike lean?

Centripetal force

The force pointed toward the centre of the turn. On a bicycle it comes almost entirely from friction between tyres and road.Source: How far can a road bike lean?

Corner radius

How tight the corner is, in metres. With speed it gives the ideal lean: θ = atan(v² / (g · r)). At 30 km/h and 15 m that is about 25.3°.Source: Lean angle calculator

Pedal touch-down angle

The lean angle where the inside pedal reaches the road. With the Krengo defaults the estimate is about 36.2°. It is a model, not a measurement, and the field does not detect contact. The field shows CLEAR* while you are clear of the limit and PEDAL NEAR close to it.Source: Pedal touch-down angle

Apex

The point where your path comes closest to the inside of the bend. A late apex puts that point farther around the bend than its geometric midpoint.Source: Road bike cornering technique

Grip estimate (G1–G12)

A twelve-step scale for how much of an assumed grip limit the corner uses, tagged ROOM, BUSY, NEAR, OVER or HIGH. The model turns the measured lean, plus a margin, into the friction the corner demands and divides it by a capacity assumed from the surface and level you choose. It does not say how much grip the road has, it has not been validated on real rides, and it is guidance only.Source: The grip scale G1–G12

Model limit (100 %)

The limit set by the surface and level you choose, not a detected slide. Above it the corner asks for more than the model assumes you have.Source: The grip scale G1–G12

IMU

An inertial measurement unit: a chip that combines motion sensors. Its resolution or calibration indicator does not specify the accuracy of the whole system on a moving bicycle.Source: How to measure bike lean angle

BNO055

The Bosch IMU in the Krengo logger: accelerometer, gyroscope and magnetometer with onboard fusion, giving Euler angles or quaternions over I2C.Source: DIY lean-angle logger

Sensor fusion

Combining information from several sensors into one orientation estimate, instead of treating a single acceleration axis as an angle.Source: How to measure bike lean angle

Calibration status

The BNO055 reports 0–3 for system, gyroscope, accelerometer and magnetometer. A 3 means a calibrated subsystem, not proven accuracy on a bicycle.Source: DIY lean-angle logger

Zero offset

A number in degrees subtracted from the lean. Read the value with the bike upright and still and type it in, so upright shows about 0°.Source: Krengo data field for Garmin

GPS-estimated lean vs measured tilt

GPS does not observe the frame, so it can only estimate lean from speed and heading change. In synthetic tests the median error was 2.3° on wide turns, and it has not been validated on real rides.Source: Can GPS measure bike lean angle?

Evidence level

How far a claim has been tested. Krengo labels each step Built and tested, Bench only, Simulator only, Ordered or Not built yet. No ride has been logged yet.Source: How Krengo works