Build Log: Stabilised RC Motorcycle with Gyro-Assisted Cornering.

This build log covers my project to make an RC motorcycle that behaves like a real bike with stable low-speed balance and predictable cornering, and that uses a gyro-based stabilisation approach to assist the steering when the bike is upright or slow-moving.

Step one was choosing a chassis and arranging mass for good balance, and I started with a lightweight aluminium frame and a 1/8th scale fork assembly to keep steering geometry adjustable.

I separated the problems of static balance and dynamic stabilisation by aiming for a low centre of gravity first, and I placed the battery horizontally low in the belly of the frame while keeping the motor and ESC slightly rear-biased to mimic a road bike's weight distribution.

For active stabilisation I evaluated two routes: mechanical gyroscope wheels and an IMU-driven electronic steering assist, and I decided to combine a small flywheel on a dedicated brushless motor with an IMU and microcontroller so the build benefits from both gyroscopic stiffness and sensory correction.

Integration details mattered, and I mounted the flywheel vertically close to the roll axis with a high-speed BLDC capable of around 10,000 RPM, while the IMU (MPU-9250 class) feeds roll and rate data to a PID controller that nudges the steering servo to counteract unwanted lean and wobble.

Testing and tuning took the longest time because gyro effects are nonlinear, and I logged each run while adjusting PID gains, servo travel limits and flywheel speed so cornering remained responsive rather than feeling damped or hung up.

During cornering trials I focused on tyre choice, fork rake and trail, and damping, and I found that medium-stiff front damping and slightly increased rear tyre pressure improved turn-in without sacrificing grip or upsetting the stabilisation system.

As a checklist for repeatable tests I recommend doing slow-speed balance trials, straight-line wobble runs, progressive lean tests and timed slalom courses so you can tune stabilisation behaviour at different speeds and angles of attack.

I refined the wiring with a dedicated power feed for the flywheel and separate BEC for the microcontroller and servos, and I documented the parts list and photographs on my site at WatDaFeck so others can see the layout and replicate the power filtering I used.

Lessons learned include keeping the flywheel mass as small as practical to get the desired gyroscopic effect without making the bike feel sluggish, using a fast but limited servo for steering corrections, and prioritising mechanical balance before relying on electronic stabilisation.