Honda FourTrax Rubicon TRX520FA5 2020 Owner's Manual page 200

Tires
Also, if you hit a pothole or other hard object while riding, stop as
soon as you safely can and carefully inspect the tires for damage.
Tread Wear
(2)
(1)
3/16 in
(4 mm)
(1) groove depth
(2) wear indicator
To check the condition of a tire tread, measure the groove depth (1)
in the center of the tire, or check the wear indicator (2).
For best performance, you should replace a tire before the tread
depth at the center reaches the following limits:
front
rear
190 Servicing Your Honda
NEW
Replace
(3) wear indicator
location mark
3/16 in (4 mm)
3/16 in (4 mm)
(3)