All Cobalt Friction XR-Series Racing Brake Pads feature true 100% “no-bedding required” to achieve full frictional performance, unlike most traditional race pads which require very specific bedding instructions for proper function. Unmatched friction vs. temperature stability and consistency. Additionally, Cobalt Friction materials exhibit unmatched disc finish and life as compared to any competing racing friction.
Friction Material Characteristics
Cobalt XR1 is an extremely high torque material with an aggressive initial bite and medium-high, linear rising torque curve. Excellent friction stability and consistency coupled with very good modulation, threshold control and release characteristics over the industry’s broadest operating temperature range. The XR1 material has unmatched disc life and finish versus any other competing friction material of comparable torque. Well-suited for a wide range of platforms, including those with active aerodynamic profiles as well as limited downforce applications, and/or ABS-equipped as well as non-ABS vehicles, due to the direct line pressure to generated torque relationship.
Cobalt XR2 is a high torque material featuring an initial bite that is 8-10% lower than XR1, but with the same controlled transition to a linear, rising torque curve. Improved modulation, threshold control and release characteristics make the XR2 particularly well-suited for chassis and tire combinations which do not respond well to excessive initial brake energy, but still require a high average torque level. Similarly, vehicles normally equipped with XR1 can move directly to the XR2 when low-grip conditions present themselves unexpectedly (e.g. qualifying in the dry, but rain/wet conditions on race day) without sacrificing or experiencing a change in pedal feel, consistency, or brake capacity.
Cobalt XR3 is a versatile, medium-high torque material with a solid initial bite and a slightly rising torque curve. Unsurpassed cold performance, torque stability, consistency and modulation/release for this level of friction make the XR3 an ideal compound for Club Racing and Track Day/HPDE customers, particular in moderate to lower inertia vehicles. Also recommended for rear-axle use on vehicles over 2800lbs, delivering optimal straight-line braking performance, stability and controlled rotation while trailbraking.
Cobalt XR4 is a medium torque compound sharing a similar application basis as our popular XR3 material, but at lower overall friction levels. With a slightly rising torque curve at low to moderate line pressures, transitioning to a virtually flat profile at higher line pressures and temperatures, the XR4 is primarily a rear-axle compound for vehicles under 2800lbs. However, the excellent cold performance, friction stability and consistency of the XR4 also make it a class-leading autocross compound on vehicles up to 3200lbs.
Cobalt XR5 is a specialized low torque material designed specifically for rear-axle applications on vehicles exhibiting a rapid rate and high magnitude of weight transfer under braking, e.g. FWD or low-inertia RWD vehicles. Solid initial bite with a perfectly flat torque profile, transitioning to a negative slope (i.e. negative torque gain versus temperature) virtually eliminates rear lock-up. Cobalt XR5 is the rear-axle compound of choice for championship winning drivers and teams in Grand Am Continental Tire Series, SCCA Spec-Miata, Showroom Stock and IT classes.
Source: Cobalt Friction