Request to clarify Disc Brake rules bearing retainer & weights
#26262 from Gregory Bruns · Rule change · TB 19-04 (2019-04 Fastrack)
In GCR section 9.1.1.C.4.D, make changes as follows:
“Front and/or rear brake drums and backing plate assemblies may be replaced with a disc
brake conversion assembly as an option. The front spindle/steering knuckle, rear axle, axle
tube, bearing housing and bearing retainer/seal assembly must remain per GCR part 9.1.1. A
spacer plate or a portion of the rear caliper support may be fitted beneath the bearing retainer
to replace the backing plate dimension. If the caliper bracket is attached to the inboard side
of the rear axle tube bearing casting with the bearing cap retainer bolts, the casting area
around the bolts may be surfaced to achieve an adequate contact surface. Any ferrous alloy,
Show 11 more lines
unvented rotor may be used, but must have a maximum diameter of 11.75 in. and a minimum
thickness of 0.20 in. The otherwise smooth rotor may have a maximum of three pad cleaning
grooves per side. Any ferrous or aluminum alloy caliper and caliper support may be used. The
caliper must have no more than four pistons and weigh a minimum of 1.65 lbs. Brake pads are
free. Any hub assembly may be used as long as it can be fitted with part 9.1.1. wheels. The
required minimum weight for the complete disc brake assembly is 16.5 lbs. The A assembly
includes the following components: hub assembly; rotor hat; disc - the disc (which may be in
two pieces); any hat-to-disc mounting hardware; calipers; bearings (front), for the front; pads;
caliper bracket; assembly hardware, (not including the brake assembly to spindle hardware for
the front or the brake assembly to axle housing hardware for the rear); and lugs or studs with
nuts.”