Originally Posted by wsmc831
Yes, that is a fast way to replace fork oil. Though you won't ever get it all out, and there is no way to determine proper and equal amounts in each fork unless you remove springs and measure air gap.
Once the forks are off taking the caps and springs off takes and addition few minutes, so why not?
Proper and equal is easy. I have a bamboo skewer in the garage with tape around it I use as a refill marker. Do it properly once, measure and mark it once with the front fully down and the springs poking out.
Next time loosen the top clamp bolts, undo the caps, push the front of the bike down, pump the oil out that you can get at from the top (~2/3) (my forks don't have lower drain holes) and refill with fresh to the mark. Put it back together.
5 minutes every six months is a LOT less effort than several hours every two years, and I'll bet on average my oil is in better condition than yours. It's not engine oil (where this would be a bad idea) it ages totally differently.