Unyielding performance & powerful braking are the hallmarks of the Racer kit. Designed specifically for road bikes the Racer kit will provide consistent & smooth shifting & amazingly powerful braking. The Racer kit features Jagwire's 4mm derailleur housing lined with its proprietary L3 liner technology. For the brakes we use Jagwire' s legendary Kevlar® reinforced compressionless Ripcord housing with proprietary L3 liner.