Progressive Fork. Too much oil ??

Sag at 30%. Can only get 100mm travel out of fox 140mm fork. It doesn’t feel broken. I have religiously completed the seal maintenance and probably added a little extra oil each time (just for good measure 😉

Could this ‘extra oil’ be causing it to ramp up more than it should ?

If it is, and I drain the fork, how much oil should I put back ?
(it’s a 2012 RLC 140mm Kashima FIT one)

Thanks guys

yes – too much oil can cause it to ramp up depending on the internal layout of the fork.

I found my floats too progressive. After check oil volume, I cut down the piston rod to increase the volume of the air spring.

Probably, remove all air and check they can be fully compressed.

Plus one ^ it will rule out or confirm the hydro lock you suspect.

If you are filling the air chamber with extra oil, then yes.

p.s. it might still compress fully once you let the air out (i.e. it may not completely ‘hydro-lock’, but the air volume may be small enough that it is extremely progressive).

p.p.s. as above, I cut the piston rod down on my f120s to make them more linear.

even if the extra oil is in the lowers in can cause hydraulic lock depending on the internal configuration

where have you been putting this extra oil?

The only way to make sure you have the right amounts of oil would be to drain both legs and then re-add according to the fox documentation. (Because yours are FIT, its probably something like 30ml in each leg)

Rudedog- I have been putting the extra oil in the lowers. I’ve completed the dust wiper seal maintenance four times in 10 months and each time added 5-10 mls per leg.