Honda CRF450RX 2020 Owner's Manual & Competition Handbook page 122

Brake Pad Wear
Brake pad wear depends on the severity of usage
and track conditions. (Generally, the pads will
wear faster with wet and dirty track conditions.)
Inspect the brake pads at each regular maintenance
interval (pages 25, 26).
Front Brake Pads
Inspect the brake pads (1) through the front wheel
to determine the brake pad wear. If either brake
pad is worn anywhere to a thickness of 0.04 in (1.0
mm), both brake pads must be replaced.
minimum
thickness indicator
(1)
replace
0.04 in (1.0 mm)
wear indicator
grooves
(1) brake pads
Rear Brake Pads
Inspect the brake pads (1) from the rear side of the
caliper (2) to determine the brake pad wear. If
either brake pad is worn anywhere to a thickness of
0.04 in (1.0 mm), both brake pads must be
replaced.
0.04 in
(1.0 mm)
(1) brake pads
(2) rear brake caliper
(1)
(2)
minimum
thickness indicator
0.04 in
(1.0 mm)
(1)
replace
Other Inspections
Check that the front brake lever and rear brake
pedal assemblies are positioned properly
(page 114) and the securing bolts are tight.
Make sure there are no fluid leaks. Check for
deterioration or cracks in the hoses and fittings.
Servicing Your Honda
Brakes
117