As the tire tread wears down, the tire becomes more susceptible to puncture and failure. An accepted estimate is that 90% of all tire failures occur during the last 10% of tread life (90% worn). So it is false economy and unsafe to use the tires until they are bald.
If any measurement is less than the service limit, replace the tire (see Tire Removal/Installation in the Wheels/Tires chapter).

Tread Depth Standard:
Front 3.6 mm (0.14 in.)
Rear 5.3 mm (0.21 in.)
Service Limit:
Front 1 mm (0.04 in.) (AT, CH, DE) 1.6 mm (0.06 in.)
Rear 2 mm (0.08 in.) (Up to 130 km/h (80 mph)) 3 mm (0.12 in.) (Over 130 km/h (80 mph))
| WARNING Some replacement tires may adversely affect handling and cause an accident resulting in serious injury or death. To ensure proper handling and stability, use only the recommended standard tires for replacement, inflated to the standard pressure. |
NOTE
Wheel/Tire Damage Inspection
Wheel Bearing Damage InspectionCAN Communication (Transmission)/CAN Bus OFF Monitor Inspection (Service Code
b 57) CAN Communication (Reception) Monitor Inspection (Service Code b 58)
Remove:
Seat (see Seat Removal in the Frame chapter)
Immobilizer (Equipped Models)/Kawasaki Diagnostic
System Connector Cap [A]
Measure the CAN communication line resistance.
Immobilizer (Equipped Models)/Kawasaki Diagnostic
System Connector [A]
GY/BL Terminal [B]
LB Ter ...
Drive Chain Slack Inspection
NOTE
Check the slack with the motorcycle setting on its sidestand.
Clean the chain if it is dirty, and lubricate it if it appears
dry.
Check the wheel alignment (see Wheel Alignment Inspection).
Rotate the rear wheel to find the position where the chain
is tightest.
Measure the ver ...
Handlebar Installation
Apply a non-permanent locking agent to the threads of
the handlebar positioning bolts and tighten them.
Torque - Handlebar Positioning Bolts: 9.8 N·m (1.0 kgf·m,
87 in·lb)
Install the steering stem head with handlebars.
Install the washer [A] and steering stem head nut [B].
Tighten:
...