EBC 15-17 KTM 250 Duke (250cc) CSK Coil & Diaphragm Spring KitsAlways fit new springs, which get tired after miles of heat and use. EBC spring kits are 10% stiffer than standard and are sold in engine sets. As stated in general fitting safety instructions, advise customers that lever will feel slightly heavier when uprating springs and to test ride to acquaint themselves with the change in control. New diaphragm springs now available.