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 InspectionSteering Play Inspection
Remove the lower fairings (see Lower Fairing Removal in
the Frame chapter).
Raise the front wheel off the ground with the jack.
Special Tools - Jack: 57001-1238
Jack Attachment: 57001-1608
With the front wheel pointing straight ahead, alternately
tap each end of the handlebar. The f ...
Fuel Tank and Cap Inspection
Visually inspect the gasket [A] on the tank cap for any
damage.
Replace the gasket if it is damaged.
Check to see if the water drain pipe [B] and fuel breather
pipe [C] in the tank are not clogged. Check the tank cap
breather also.
If they are clogged, remove the tank and drain it ...
Clutch Lever Installation
Install the clutch lever so that the mating surface [A] of the
clutch lever clamp is aligned with the punch mark [B] of
the handlebar.
Tighten the upper clamp bolt first, and then the lower
clamp bolt.
Torque - Clutch Lever Clamp Bolts: 7.8 N·m (0.80 kgf·m, 69
in·lb)
There will be ...