Fork Oil

[Miz]

While I've got the front end stripped for new head bearings I am changing the oil in the forks, now I've got a question!!

Which is most important 425ml or 160mm?

[shedmonkey]

i would think the height takes into account any small differences between the legs like small amount of undrained oil etc. And so air spring effect between the 2 legs is the same. But if you are asking are they about the same amount of oil volume or height then i have no idea. Got to say its rare for you to ask a question you usually answer them

[snapdragon]

asking my expert by txt
-- he says the 160mm as that takes account of any residual oil

(why do I always mis-remember that measure as 140mm??? )

[Fausto]

I'd go with the 160mm measurement too but make sure there's no air trapped in there.

[V4mp]

160mm, because its possible that there is trapped old oil in the forks and if you put 425ml of new oil into fork leg you can have different amount of oil between your fork legs. Hopeful that is understandable text.

[Miz]

i would think the height takes into account any small differences between the legs like small amount of undrained oil etc. And so air spring effect between the 2 legs is the same. But if you are asking are they about the same amount of oil volume or height then i have no idea. Got to say its rare for you to ask a question you usually answer them

Its an age thing

Now I need to work out how to strip the Xtra forks, as the manual only describes the normal forks.

[Spyke]

I'm glad you asked Miz, because I'm now in a similar boat! BUT the manual says the mm should be measured without the spring - does that REALLY mean I should take the spring out of the "spring/plunger/fork cap assembly"? Or did they mean to say "without the spring/plunger/fork cap assembly inserted in the tube"?

I really don't want to have to take the fork cap off and the spring right out, as I'm pretty bloody sure that at the last turn of a nut some bits will go flying into the dark and spider-infested corners of the garage - and remember we've got killer spiders down here!

I don't actually need to have the bike back together until Saturday morning, so can't I just drain the "spring/plunger/fork cap assembly" slowly and carefully both ways then add the correct volume of clean oil? I've pumped the plunger so I'm thinking it "should be" close enough if I drain the assemblies the "right way up" tonight, and then tomorrow night drain them the "wrong way up" with clean rags jammed into the springs to absorb whatever drips down inside on the plunger. Am I barking mad to even consider this?

[Miz]

I'm glad you asked Miz, because I'm now in a similar boat! BUT the manual says the mm should be measured without the spring - does that REALLY mean I should take the spring out of the "spring/plunger/fork cap assembly"? Or did they mean to say "without the spring/plunger/fork cap assembly inserted in the tube"?

I really don't want to have to take the fork cap off and the spring right out, as I'm pretty bloody sure that at the last turn of a nut some bits will go flying into the dark and spider-infested corners of the garage - and remember we've got killer spiders down here!

I don't actually need to have the bike back together until Saturday morning, so can't I just drain the "spring/plunger/fork cap assembly" slowly and carefully both ways then add the correct volume of clean oil? I've pumped the plunger so I'm thinking it "should be" close enough if I drain the assemblies the "right way up" tonight, and then tomorrow night drain them the "wrong way up" with clean rags jammed into the springs to absorb whatever drips down inside on the plunger. Am I barking mad to even consider this?

That's just what I did, and I've not noticed any problems since.

[Spyke]

Awesome, cheers Miz! I've also wondered about the differences between the workshop fork specs and the Xtras, but I'm guessing that you followed the v/normale specs and put 425ml in each, and haven't noticed issues so I'll head down that path too.