Spark is aerodynamics series road bike, it has small stack which could move upper body centre of gravity forward and get better control. S and XS size have a smaller headtube angle and bigger fork offset which will bring a better trail. The BB drop of Spark is 68mm it brings good cornering stability  The geometry design of Spark make sure the big size and small size all have cornering stability flexibility.
 
Spark geometry is not so aggressive, it is more friendly than Spark EVO, different sizes have different headtube angle, Seatpost has 0°and 25°offset option.