The default measurement range of the accelerometer is +/-2g in all 3 axes. However, the micro:bit accelerometer hardware (MMA8653FC) has configurable ranges, and can stretch as far as 8g.

Javascript Blocks Editor

Choose set accelorometer range from the Input blocks and cange the value to 8g

Python Editor 

Micropython allows you to read 3g, 6g and 8g gestures

C++ Runtime

The underlying runtime code (the DAL) written in C++ by Lancaster Uni, allows this to be chosen at runtime by calling setrange

Keywords for search: 8g, range of the accelerometer, measure, maximum