Honda TRX420TM Owner's Manual page 164

Tyres
Also, if you hit a pothole or other hard object while riding, stop as soon
as you safely can and carefully inspect the tyres for damage.
Tread Wear
FRONT
NEW
(2)
REAR
(1) groove depth
(2) wear indicator
To check the condition of a tyre tread, measure the groove depth ( ) in
the centre of the tyre, or check the wear indicator ( ).
For best performance, you should replace a tyre before the tread depth at
the centre reaches the following limits:
front
rear
Servicing Your Honda
154
4 mm
(0.16 in)
Replace
Replace
4 mm
(0.16 in)
NEW
(1)
(3) wear indicator
location mark
2
4 mm (0.16 in)
4 mm (0.16 in)
(3)
1