Big brakes have been a big deal in rock crawling and rock racing. We’ve been manufacturing 14″ diameter rotors since the early rock crawling days, and the extra stopping power at lower speeds has become an easy must-have. That being said, in today’s Ultra4 vehicles, especially those newer IFS powered versions, the large 14″ diameter rotor is a bit tight. Factor in mud and debris from those east cost races and clearance between the caliper and wheel can be an issue.

As such, the need for a slightly smaller rotor is born. Enter our prototype 13.5″ diameter rotor, which starts as Wilwood GT-36 Vented Rotor, precision machined down from 14″ to 13.5″. Brake hats, calipers, and pads all work as-is. The caliper pad also has full rotor contact, so no compromises either.

We’re giving these a test now, and so far so good; the extra caliper clearance for those that need it is obvious and welcome, and this rotor should do the trick. Stay tuned for more details.