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Discussion Starter · #1 ·
I realize there is a huge thread on the Pike in this forum, but given that I am subscribed to it and failed to realize this was an issue, I thought I'd make a new post.

Short version: The seals at the top of the lowers on the Pike are very good, and they can trap a substantial amount of air pressure. In some cases, this can completely ruin the performance of your fork. Bleed the air by emptying the air chamber and sliding a thin piece of plastic in between the stanchion and dust wiper until you hear a hiss.

Long version: I loved my Pike when I first got it, but over time, and especially lately, had been experiencing a significant loss of enthusiasm about it. This culminated in a trip to Mammoth where I really just couldn't believe the level of arm fatigue I was getting. I chalked it up to being out of shape and that my Tallboy LTc just wasn't cut out for park riding. Cut to a few weeks later, I remember something about this air trapping issue and decide to check it out. There was significant resistance to compression even with the air cap removed, so I executed the cable tie bleed technique and released quite a bit of pressure.

I had thought it curious that I only needed ~72 psi to get desired sag (~25%) out of the Pike even though I'm 220 lbs geared to ride. After bleeding the lowers, I had to up the pressure to 90 psi in order to have a rideable fork! (Much closer to what Rock Shox recommends for my weight.) On the subsequent ride, my fork was back to it's good old self with the excellent small bump compliance and mid-stroke support I remembered. I'm super happy about this.

So if you own a Pike or took a ride on one and are disappointed, consider that this may be the issue. I was absolutely blown away by the effect it had on the performance of the fork, and I think the air pressure change I had to make speaks for itself. It's a fantastic fork, as long as air trapped in the lowers isn't creating an undesired spring rate that completely alters its behavior.
 

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I had the same experience but with a Talas 34. I removed the lowers because they were riding harsh, and pressure was released when I knocked loose the shaft. Like you, I had to increase the pressure and they are working much better.
Thanks for the ziptie-under-the-wiper suggestion, I didn't think of that as an alternative to unbolting the shafts.
 

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HAHA PWN
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Can you post some pictures or a link to it? I've been having the same issues and it's driving me nuts! Thanks in advance.
 

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huh. While i haven't had any complaints about the Pike's performance, I was a bit mystified at running 65 PSI for correct sag. Sure enough, I tried the air bleed, and when I re-set the sag it is right at RS's recommended pressure (~80 psi).

Thanks for the tip.
 

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Discussion Starter · #5 ·
Can you post some pictures or a link to it? I've been having the same issues and it's driving me nuts! Thanks in advance.
Basically, at the seals where the stanchions enter the lowers, there is a dust wiper and then underneath that, the actual seal. You need to insert something in between to temporarily break the seal and release the air. The thinner the better, and nonmarring so you don't scratch the stanchion. The thin end of a small cable tie works great. Just stick in in between the dust wiper and stanchion and keep inserting till you hear a hiss. Then you are done.
 

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Basically, at the seals where the stanchions enter the lowers, there is a dust wiper and then underneath that, the actual seal. You need to insert something in between to temporarily break the seal and release the air. The thinner the better, and nonmarring so you don't scratch the stanchion. The thin end of a small cable tie works great. Just stick in in between the dust wiper and stanchion and keep inserting till you hear a hiss. Then you are done.
So this should be done on both sides...
 

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Now, if someone would come up w/ a way to inject some grease into that tiny space/channel between the seals...
 

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Discussion Starter · #11 ·
Why would you need to air down to do it? You want to equalize when it's topped out.
Yeah that's fair. You just need to air down to see the effect of it (i.e. the inability to compress the fork and have it stay down).
 

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I'm at 68psi and still only around 20% sag... RS says I need to be 75-85psi.

I swear I've heard a "pssssssst" on the last ride or two... Trying this tonight.
 

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I have this problem on my SID. Seems like the negative air chamber must be leaking into the lowers. I replaced my seals but the problem came back in ~2 months. Would be nice to get to the bottom of the issue.
 

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Fixed the problem and can't be happier. I was going to have the LBS do service on it, but I only have about 13 hours on it. Thanks for the tip!
 

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I think I may have had a double whammy with the lowers pressure and an overfilled damper.

With the fork at full extension, I pulled out the LSC snap ring and adjuster and it gave up a few cc's of damper fluid. I think the bladder was hitting the walls of the stanchions at full compression.
 

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If you opened the damper while you still had pressure built up in the legs, it likely wasn't overfilled. That was most likely built up lower leg pressure acting on the bladder. There is no static force on that bladder except for ambient air pressure within the leg.

The only way, that I know of, to tell if it's overfilled is by installing the damper into the upper leg (lowers off), and cycle all the way to see if the bladder hits the ID of the stanchion and restricts any more displacement. It's not like a MX cartridge where you have a big spring instead of a bladder and can feel for top-out force if it's overfilled.


This air burping trick works for any fork as well, not just the Pike. Fox, X-Fusion, Zoke, etc. Film negatives work great too.

With how quickly this happens, and how customer complaints about forks over the last decade or so have almost all related to compliance and arm pump, I find it astonishing that quick bleeders are NOT standard features on all high-end forks now.
 
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