True to Leach's ST mission statement, the ST170's chassis benefits from a few modest but extremely well executed changes. Obviously the larger tyres play a major part in the ST's increased road-holding and sharper handling, but so too do ten per cent stiffer springs and larger diameter dampers. Amazingly the anti-roll bars remain unchanged from the stock Focus, save for some rear bushing tweaks, whilst the steering benefits from special gearing and a new pump that provides less assistance at higher revs.