OEM shock health?

[Turboflash]

Basic question for the thread is how does one assess or know what the relative health of your sled's shocks are?
I know all shocks need maintenance/service as some point. Questions are:
1. What determines when a shock needs service - is it miles or time?
2. What are the clues (when riding or in the garage) that your shocks are in need of attention? Obviously leaking oil is a big one but what else tells you it's time to service them?
3. When it's time for service, what needs to be done? Is it just changing the oil and recharging the nitrogen or is there more? Are there better (higher-quality) parts to use when getting shocks serviced? Whose oil is best?
4. Are there shocks that have longer service intervals compared to the OEM shocks Yamaha and Cat use? Why?

Thanks for info, advice, suggestions.

 

[PowderFalcon]

I had mine serviced this off-season on my ‘19 with 5100kms on it. Was told they should be done the 4000km mark. My center shock was full of water and leaking oil. Fronts were ok, as was the rear. I had the oil changed and also got them re-valved for my body weight and riding style. Hoping for a better performing suspension this season

 

[maim]

on my 2011 apex xtx, i can tell when they need a service as i need to turn the torsion springs up to max as when it runs out of nitrogen in the rear shock witch is usually towards the end of the second season. i then refresh all the shocks on the sled for the next season witch is why i have 2 sets of shocks for that sled so i can replace them during my pre season maintenece and get them done at a later time as the local guy that does them does not touch them all summer and only gets to them late in the fall.

all of the ones i have tried pretty much run about the same legnth of time between services and i have run olins, gytr's and stock. the ones with the external cannister seem to last a bit better as it helps keep the oil in them cooler.

 

[ClutchMaster]

I do mine ever other year and I put about 1.5~ 2k miles a year.

Shocks have a tendency to loose their dampening slowly, usually due to the nitrogen charge leaking out and oil degradation.

Using a synthetic oil like Maxima or Amsoil or Fox racing oil, will give more consistent shock dampening with temperature change. Shocks can get extremely stiff in colder weather using the standard fox oil.

Canondale does valve stack modifications if your wanting stiffer or softer dampening.
I would shoot him a PM.

 

[Mototown]

If your shocks have rebound clicker , count the clicks clock ways until lightly bottomed . Record settings. Turn rebound out , if you don't feel definite 20 clicks out , it needs rebuilding ( nitrogen is gone ) . Anything over 2000 -2500 miles should have new oil anyways . Shocks with no adjustments you manually compress shock , should return 1-2 seconds.
Any high quality motocross shock oil works , light weight maxima racing oil has worked good .