fox 40 oil change !

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fox 40 oil change !
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flag riggadon
Posted: May 4, 2010 at 9:43 Quote
what i do to lubricate the seals is just put a few drops of the same oil i use in the inside of the fork, push on the fork to get the stantions lubed, then wip it off
flag riggadon
Posted: May 4, 2010 at 9:55 Quote
mooseman414 wrote:
IM CONFUSED. you have the damper-side and the spring-side and then the damper. where is the damper? on the fox suspension help disc it has oil measurements for both sides meaning the upper stanchions and a measurement for the damper. where does that oil go???

if you are standing over the fork, like when youre riding, the damper is on the right side, and the spring is on the left, hence the preload spring adjust on the left and rebound adjust on the right. if you have ever taken apart your fork, you will see that the damper is just a long rod going from the rebound adjuster all the way down to the compression adjusters. there are no seperate chambers or anything. the spring side is slightly different. there is a plunger shaft that goes to the bottom of the fork, then a little platform for the spring to sit on, the the spring, spacers, and finally the topcap. the amount of oil is the same for both sides, i use 40-50ml on each side of the fork. the oil just sloshes around in the fork, lubing the stantions, bushings, damper seal(on the inside of the fork obviously), seals, and the spring. ist pretty simple. bottom line, if you pour oil into the top, it will come out the bottom
flag nathanbalsdon
O+
Posted: May 4, 2010 at 13:27 Quote
mooseman414 wrote:
IM CONFUSED. you have the damper-side and the spring-side and then the damper. where is the damper? on the fox suspension help disc it has oil measurements for both sides meaning the upper stanchions and a measurement for the damper. where does that oil go???

the damper is a closed cartridge system in fox 40s. The "damper-side" and "spring-side" refers to the lubricating oil in the lowers (which can be put in from the top or the bottom). The Damper oil level is the the oil actually in the cartridge.
flag schwimble
Posted: May 4, 2010 at 14:23 Quote
just a quick tip, your meant to run 35mm of oil in the lowers as lubricant

if you use a little more, like 45-50mm the fork will ramp up a little more at the end of the stroke. i use 40 in the right leg and 50 in the left to get a nice smooth ramp up at the end of the stroke.

the weight of the oil affects how the fork feels too. if you use 5w oil they will feel like butter, but youll need to service them waaaayyyy more often. 10w oil and theyll feel like ass, but youl not have to service them as often. your meant to run 7.5w oil in them.
flag riggadon
Posted: May 4, 2010 at 14:42 Quote
schwimble wrote:
just a quick tip, your meant to run 35mm of oil in the lowers as lubricant

if you use a little more, like 45-50mm the fork will ramp up a little more at the end of the stroke. i use 40 in the right leg and 50 in the left to get a nice smooth ramp up at the end of the stroke.

the weight of the oil affects how the fork feels too. if you use 5w oil they will feel like butter, but youll need to service them waaaayyyy more often. 10w oil and theyll feel like ass, but youl not have to service them as often. your meant to run 7.5w oil in them.

im trying to comprehend how the oil weight would influence the ramp up of the compressio
flag schwimble
Posted: May 4, 2010 at 14:51 Quote
no no no

read it again, the level of the oil affects the ramp up, the weight of the oil affects how smooth they feel
flag riggadon
Posted: May 4, 2010 at 16:26 Quote
schwimble wrote:
no no no

read it again, the level of the oil affects the ramp up, the weight of the oil affects how smooth they feel

HOW woudld the oil wieght affect ramp up?!?! makes no sense at all
flag mooseman414
Posted: May 4, 2010 at 18:54 Quote
the weight of the oil DOES NOT effect the ramp of the fork. it is the VOLUME of oil that is in the fork. The OIL WEIGHT effects how easy the fork moves through the travel
flag riggadon
Posted: May 5, 2010 at 9:20 Quote
mooseman414 wrote:
the weight of the oil DOES NOT effect the ramp of the fork. it is the VOLUME of oil that is in the fork. The OIL WEIGHT effects how easy the fork moves through the travel

can you explain how the volume of oil would affect the ramp up?
flag schwimble
Posted: May 5, 2010 at 11:54 Quote
well im the one that said it originally, and no, i cannot explain it completely....but it does affect the way the fork ramps up, i know this for a fact because its something ive played with a lot....the guy that told me to do it is a techy on the WC circuit and knows his shit

my theory is, and this is just my speculation, that when the stanctions compress into the lowers with the normal amout of oil, the bottom of the stanction doesnt hit the oil. when the oil level is raised tho, the bottom of the stanction will hit the oil and it will act as damping because there is just a hole (maybe 8mm across) at the bottom of the stanction. the high the oil level above normal the earlier it will ramp up. thats my theory and if ya look at the internals i reckon it makes sense.
flag riggadon
Posted: May 5, 2010 at 11:59 Quote
schwimble wrote:
well im the one that said it originally, and no, i cannot explain it completely....but it does affect the way the fork ramps up, i know this for a fact because its something ive played with a lot....the guy that told me to do it is a techy on the WC circuit and knows his shit

my theory is, and this is just my speculation, that when the stanctions compress into the lowers with the normal amout of oil, the bottom of the stanction doesnt hit the oil. when the oil level is raised tho, the bottom of the stanction will hit the oil and it will act as damping because there is just a hole (maybe 8mm across) at the bottom of the stanction. the high the oil level above normal the earlier it will ramp up. thats my theory and if ya look at the internals i reckon it makes sense.

that would make sense, except that the stantion is just a long hollow tube, no holes on the top or bottom. so there would be no flat surface to cause pressure against the oil.

ill try that out though, it would be nice if my 40 had a little more ramp up
flag schwimble
Posted: May 5, 2010 at 12:12 Quote
pull the stanctions out some day, youll find there is a flat surface at the bottom with an 8mm(ish) hole in the middle on the spring side stanction
flag riggadon
Posted: May 5, 2010 at 12:24 Quote
schwimble wrote:
pull the stanctions out some day, youll find there is a flat surface at the bottom with an 8mm(ish) hole in the middle on the spring side stanction

i know, but the flat part sits on the lunger shaft, so it cant push on the oil
flag schwimble
Posted: May 5, 2010 at 12:37 Quote
its part of the stanction, or, at least it moves in unison with the lowest part of the stanction so what does it matter what it sits on?

lunger shaft??? are you talkin about the damping side?
flag riggadon
Posted: May 5, 2010 at 13:31 Quote
schwimble wrote:
its part of the stanction, or, at least it moves in unison with the lowest part of the stanction so what does it matter what it sits on?

lunger shaft??? are you talkin about the damping side?

sorry, i meant plunger shaft. the left side of the fork goes like this, from bottom to top:
nut
plunger shaft
spring
spacers
top cap

the plunger shaft is the thing that stick out of the bottom of the fork, the thing that the nut threads into. the rod on the plunger shaft is like 6 inches long, then theres a platform that the stantion sits on, and the spring is inside the stantion resting on the platform that the plunger shaft provides. its hard to explain with words, but basically its not possible for the flat part at the bottom of the santion to push on the oil which would add more ramp up.

it doesnt really matter though, lets try to stay on topic here

 


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