Check condition at 60.000km (37.000mi)
Replace at 120.000 ( 74.000mi) OR after 4-5 years.
The same goes for alternator/ac belt.
Clutch only when it starts slipping or other problems related.
Alternator only if you have charging or bearing noise problems.
Starter motor you will be the first to know if it's the time haha. Very very rare.