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 InspectionClutch Installation
Apply engine oil to the needle bearing [A] and the sleeve
[B].
Install:
Needle Bearing
Sleeve
Install the clutch housing [A].
Fit the holes [B] and projections [C].
Engage the clutch housing gear and the crankshaft primary
gear.
Install the spacer [A] and the clutch ...
Exhaust Butterfly Valve Actuator Inspection
NOTE
Be sure the battery is fully charged
Remove the front seat (see Front Seat Removal in the
Frame chapter).
Turn the ignition switch to ON.
In the left side view of the motorcycle, check to see
the pulley [A] clockwise [B] and counterclockwise [C]
smoothly.
The pulley turns ...
Shift Pedal Installation
Install the rubber damper to the shift pedal.
Turn the chamfered side to inside.
Assemble:
Shift Lever [A] and Locknut [B] (Left-hand Thread)
Shift Pedal [C] and Locknut [D]
Tie-Rod [E]
Turn the grooved end [F] of the tie-rod to the shift lever.
Apply grease to the sliding ...