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Discussion Starter · #1 ·
Just did a travel reduction on a 2009 F100 RLC. 90mm now. I tried to do it by the book, printing instructions, ordering all the parts right from Fox, etc. The only issue I wasn't clear on was how much oil to pour back in the bottom of the left air-spring leg. The Fox site isn't clear, it mentions 20 ml, but the Fox guy on the phone said 30 ml. He was very clear that's what they use.

So when I drained the factory oil from the leg during disassembly, it seemed like more than even 30ml came out. I didn't measure it, as it spilled all over a cardboard box I had laid down. But when it came time to pour the new oil in, I measured precisely 30 ml and it just didn't look like very much.

So, are there any Fox F-series experts here that can shed some light?

The issue I'm having is at the same exact air-spring pressure of 95 psi, the fork is a bit "softer" now, sinking down into it's travel more than I recall. I have to pump the air spring up more than my 95 to get it to feel kind of firm like before.

Would the oil amount in that leg have the effect of softening the overall fork?

I didn't touch the right leg with the lockout/compression knobs, JUST the air spring side.

Any thoughts?
 

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curtlo-dork said:
Just did a travel reduction on a 2009 F100 RLC. 90mm now. I tried to do it by the book, printing instructions, ordering all the parts right from Fox, etc. The only issue I wasn't clear on was how much oil to pour back in the bottom of the left air-spring leg. The Fox site isn't clear, it mentions 20 ml, but the Fox guy on the phone said 30 ml. He was very clear that's what they use.

So when I drained the factory oil from the leg during disassembly, it seemed like more than even 30ml came out. I didn't measure it, as it spilled all over a cardboard box I had laid down. But when it came time to pour the new oil in, I measured precisely 30 ml and it just didn't look like very much.

So, are there any Fox F-series experts here that can shed some light?

The issue I'm having is at the same exact air-spring pressure of 95 psi, the fork is a bit "softer" now, sinking down into it's travel more than I recall. I have to pump the air spring up more than my 95 to get it to feel kind of firm like before.

Would the oil amount in that leg have the effect of softening the overall fork?

I didn't touch the right leg with the lockout/compression knobs, JUST the air spring side.

Any thoughts?
by changing the travel,you have changed the air chamber size. Just put as much air in to get the right amount of sag. The air volume you just changed will change how the for rides, and 30ml is correct.
 

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Discussion Starter · #4 ·
Ah, didn't think of that. Since the fork is originally a 100mm, would the 80mm chart for setting air pressures/sag be different? I just assumed the air spring would be the same. It seems the air chamber would be smaller now and require less pressure? I guess it doesn't matter, I'll just re-do the sag and feel and keep a note on what the new air pressure should be. Thanks for the info.
 
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