Ans: Ideally, your mountain bike forks should be serviced every 20 to 30 hours of riding. This includes disassembling the forks, inspecting them, and cleaning and re-greasing them. However, in case the mountain bike fork appears to be relatively clean, you can easily ride it for 40 hours without the need of stopping in between for servicing. As recommended by Fox, mountain bike forks and shocks can last for 125 hours.