Main rotor blade clearance is the answer. The Lynx collective range goes into negative pitch, primarily to 'push' the aircraft down onto the deck during shipboard operations in rough seas. It stops it being thrown off before the groundcrew have secured it.
I flew Army mk 7s and 9s and after an engine or governer change, torque matching was done on the ground in negative pitch. The RRPM was plotted against torque for each engine to obtain the best FTG matching. Pushing 100% torque with the lever down reverses the coning angle somewhat. The introduction of the BERP blades with their paddles and greater washout even more so.
Also, the Lynx and the Bo105 both have semi-rigid heads. They both have rotation around the pitch change bearings and as such have tie-bars fitted. the only 'rigid' head I am aware of is the EC135. It has the blades bolted directly onto the rotor mast. No hinges and no bearings! The best design yet.
