To import the model into your scene, choose'File - Link/Append', then choose the given blend file, then append the Collection "Mastercollection_Vintage_motorcycle_Ariel_550_SV". All Objects are organised within.

Use the Empty "MAIN_Vintage_motorcycle_Ariel_550_SV" to poition the whole bike.
Use the Empty "Steering_Rotate_about_local_z-Axis" to rotate the steering. Rotate - as the name suggest - about the local z-axis of the empty.
The cables on the Handlebar will deform during the steering, as they are controled by Hooks.

Use the Empties "Tyre_Center_Front" and "Tyre_Center_Rear" to rotate the Wheels.