Tuning and Maintenance
If your Clutches are set up correctly and you are an average rider 1500-2000 is a good number, or 3 years Max.
I have found that age and cold temps are as big a factor as Miles.
Belts get brittle.
It like the old ladys car with 15,00 original miles on it. She changes the oil every 2000 miles, but it takes her 10 years to put 2,000 miles on it.
Take your belt off durnig the summer and let it retuirn to it original state.
Support you sled by the rails, back the springs off.