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 InspectionRear Shock Absorber Removal
Remove:
Lower Fairings (see Lower Fairing Removal in the Frame
chapter)
Fuel Tank (see Fuel Tank Removal in the Fuel System
chapter)
Bolts [A] (Both Sides)
Foot Guard [B] (Both Sides)
Squeeze the brake lever slowly and hold it with a band
[A].
WARNINGBe sure to h ...
Crankshaft Removal
Split the crankcase (see Crankcase Splitting).
Remove:
Connecting Rod Big End Nuts [A]
Connecting Rod Big End Caps [B]
NOTE
Mark and record the locations of the connecting rods
and their big end caps so that they can be reassembled
in their original positions.
Remove the crank ...
Parts Removal/Installation
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions. Turn the ignition
switch OFF. Do not smoke. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light.
NOTICE
...