www.DaveMossTuning.com
Fork oil wears out just like engine oil. Changing it every 5000 miles (8000 km) is excellent, every 8000 (13,000 km) is good, every 10,000 (16,000 km) is okay, and by 12,000 (20,000 km) it's become more like fork water than fork oil.
www.DaveMossTuning.com