Video: The Ins & Outs of the Fork Dust Seal

Apr 23, 2020
by FOX Factory  

In episode eight of Season 2, DIALED checks in with World Cup technicians Taj and Jules as they take viewers through the ins and outs of the fork dust seal and why it's so important. Jordi also runs through the all-new bleeders on the 36 and 38.

bigquotes"We all use them, and we all abuse them, but do we really know what they do? There are four main parts to the dust wiper seal..."

Enjoy our check-in with Taj and Jules? What do you want to see next the DIALED tech team cover next? Comment below!

Posted In:
Videos Fox Racing



52 Comments

  • 59 6
 My 2 cents - If you just install new dust wipers every time your fox fork goes in for a creaky CSU swap anyway, they should stay pretty fresh...
  • 13 0
 Cool! I used to work for Saint-Gobain and our site in SoCal made Fox’s fork wipers/seals for many years, as well as Space Shutte fuel tank seals, among other things like medical device seals. Love seeing this sort of tech talk on Pinkbike...more please!
  • 2 0
 @WRCDH The company I work for buys seals and o-rings made by saint-gobain. They are crazy expensive! Like 100-250 dollars for one seal.
  • 2 0
 @srsiri23w: I just spent over 2k per seal for a tool that I was working on for testing...
  • 13 1
 At this time of stanchions, this has my seal of approval...
  • 2 3
 don't be under pressure
  • 2 1
 @mtbxever: let the pressure of by pushing the knob
  • 9 0
 Some seals were harmed in the making of this video
  • 8 2
 Jordi continues to use his van's emergency tool kit for suspension maintenance I see.
  • 1 0
 seems legit
  • 3 0
 Get him a proper tool kit for Christmas, the Fox techs must be beside themselves.
  • 7 1
 Knipex pliers wrench, if you regularly work on suspension you would already have a set!
  • 1 0
 @loafersmate: those look great, I thought he was just using some old channel locks!
  • 2 5
 @loafersmate: I must of missed the Knipex torque pliers where can I find them?
I have a fully equipped shop do All my own repairs on cars bikes A/C boilers etc so I know tools.
Those are fancy plumbers pliers, use those on aluminum more than a few times and you will know.
  • 1 0
 @lake-st: Clearly you have never used those. The best suspension shops and mechanics use knipex. Specifically on Aluminium, they give you a better surface contact than a wrench and cause less damage to the surface. They may be fancy plumbers pliers, but they do a better job than any bike specific tool more often than not.
  • 2 2
 @MrDuck: If the part only two flats like shock internals there is no choice. But you still cannot torque, and if its 6 sided the Knipex is no where close to a proper tool.

have used them just would never buy a pair.
  • 1 0
 @lake-st: Crows feet adapters exist for torquing assemblies that are only across flats
  • 1 1
 @Shiny-side-up: Sure you use them with a torque wrench 1/4-3/8 or 1/2 drive not a set of pliers.

and the torque has to be recalculated, relative to the length of the crowfoot adapter.
  • 2 0
 So when gaining significant elevation with the new Fox air release... pressing the button at the top of the mountain to release air pressure build up makes sense....but when descending back down wouldn't you then be creating a negative pressure vaccum inside the lowers? How would you release this negative pressure since air can only go out? ....talking thousands of vertical difference...like driving up into the mountains and bike park.
  • 4 0
 there's some kind of missconception around forks vs. elevation, I think. How can elevation affect pressure/behavior of the fork if a fork is airtight and built of metal?
If you release pressure at high elevation there's some air release due to the lowers equalizing with the lower ambient pressure, but the actual pressure in the lowers was the same it would have been at sea level.
I think when someone feel suspension working worse at elevation, what they really feel is the tires, since they are the ones affected by ambient pressure and they harden up the lower it is.
  • 3 2
 Not really a question, just something I remember...There was a guy that used to do service videos for rockshox forks, I forget his name, but when he did a lower leg service and before he tightened the foot nuts, he would compress the fork to purge all the air out of the lowers. Then he would tighten the foot nuts. That created a sort of vacuum in the lowers when you pressurised the forks. I'm guessing it wasn't a good idea as it effectively sucked the forks in to their travel. If you were to press down on a set of new fox forks and then press the bleed button, you would achieve the same thing. Makes the initial breakaway force very light but you lose a lot of travel. Any comments on that?
  • 12 2
 The vacuum is the solution used in vacuum cleaner to catch all the dust and debris. Not a good idea to put that in your fork.
  • 1 0
 @faul: Good point
  • 5 0
 @andybloomer: space in lower legs is known as secret air chamber, do as you please, but negative pressure wont stay very long in there during use because seals are better at keeping pos pressure in them than keeping positive atm. pressure out. But no, you don´t loose much if any travel, it´s not like slightly neg. pressure in the lowers creates enough force to fight 70-80 PSI in pos. air chamber. Cane creek fork example recommends 50% of travel compression when assembling forks, so you reach atm. pressure at 50% of travel when riding.
  • 1 0
 @Mondbiker: Cool, thanks. I don't do anything with it other than periodically stick a clean zip tie behind the seal to burp any pressure build up. The guy in the rock shod video fully compressed the lowers and then tightened the foot nuts, seemed odd to me
  • 9 0
 @andybloomer: Any susp. tuner will tell you not doing the zip tie thing, it can damage the seal lip and you could also push dirt inside while doing so Wink I know GMBN promotes it 3 times a month lol. It´s better to just slightly loosen lower leg bolts, break the seal from crush washers and then tighten them back up. should take about the same time and you are not damaging anything it the process.
  • 1 0
 @Mondbiker: Hadn't thought of that, much easier
  • 3 0
 @andybloomer: Just in case, don´t forget to do it with the bike up side down so you don´t pour lower leg lube all over the brake disc lol.
  • 1 0
 @Mondbiker: Yep, got that covered ????
  • 3 1
 @Mondbiker: Sounds like a great way to flog out the foot nuts over time. A zip tie wont damage the fork seals, just jam one down there & make sure it isnt dirty
  • 4 1
 @zyoungson: It's not about damage really (ie taking a chunk out), it's about any deformation that the internal seal/springs where they are beyond their yield curve and can't return to original shape and apply appropriate force to keep dirt out and fluids in. It's a balancing act that once it's compromised, there's no return.
  • 1 0
 Push the bottom,but what if you feel that not pushing it makes your fork feels the way it is supposed to feel ??????,cause I feel that after riding some forks for say 5 months,they actually starting to feel more “accurate “ in the performance ,and you could drop the high and low speed sensitivity,or maybe is just me ?
  • 3 0
 Fox, please add another button CSU we can press to let the creaking out before we ride.
  • 2 0
 Before I even watched the video I almost posted a comment saying that I missed the park tool guys. But this was great.
  • 1 0
 Jules and Taj ftw! Entertaining and informative!
  • 3 1
 Thoughts on using one of the suspension-specific lubes on the seals weekly or so?
  • 1 0
 Great way to get dust sticking to stanchions to get it nicely pulled into the fork I think.
  • 1 0
 This helps dirt from the seals get into the lowers, don't do it.
  • 1 0
 Thanks again Fox! What should we do if we use an older model fork that doesn't have the bleed valve? I assume the same problem will exist with pressure build up in the lowers
  • 2 0
 My dust seal pops out sometimes Smile

That's when I know I had a good ride.

Rockshox RS-1
  • 2 0
 This was too short!!! But great, and too short!!!
  • 3 0
 no, you are probably bored :-)
  • 1 0
 Question. Do i need to replace the seal every time I do a basic service on my lowers?
  • 2 0
 No. You’re fine saving them for your 100-hour overhaul but no need on every lowers service. Always good to have a spare set on hand in case you see that they’re damaged, through.
  • 2 0
 I like Fox Air Release Technology.
  • 1 0
 Does air get trapped in the lowers of coil sprung forks as well? Assuming yes...
  • 2 0
 Yes, the air spring has nothing to do with it. I always thought that the pressure build up came from a bit of oil vaporizing because of the way it smells when it comes out. But maybe after watching the video, I can imagine it may also be ambient air that becomes trapped as the stanchions move and rub the wipers. Either way, it isn't air from the air chamber. If it were, they wouldn't also have made a release valve on the damper side (where there is no air chamber).

I wonder whether this is the thing they learned from Marzocchi. After all they used to have these release valve on their bigger forks.
  • 1 0
 @vinay: Thanks, that was my suspicion as well. Totally different parts of the fork.. Thanks for clarifying.
  • 1 0
 Looked up the SR Suntour Durolux fork seals, and they don't look as good, but they still are absolutely astonishing.
  • 2 1
 I'd love to push those buttons! Time for a 38!
  • 2 0
 Ecky Thump
  • 1 0
 Wow. I give up.

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