Front torsion bars are one of the primary methods of tuning OTK chassis.  The standard oval bar gives you two options, very soft (less front grip) or very stiff (more front grip).  The optional round bars give you much more flexibility.  Each change produces a very noticeable effect on chassis handling.  The OTK front bars are available in 1mm (chrome) soft, 1.5mm (silver) medium, and 2mm (gold) stiff.  These are a must have for all OTK chassis owners.