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  1. #1
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    Pike won't fully extend after travel change

    I just finished changing the air piston on my pike to increase its travel from 150 to 160 mm. I can't seem to get it to fully extend since the piston change. If I pull down on the lowers I can get it to extend, but not with just pressurizing the air chamber. When I reassembled I made sure to get all the air out of the fork and have retried, but I still can't get it to extend. Any ideas?

  2. #2
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    I had this same issue, although not after a piston change. For me it was that some air made its way from the positive to the negative side.

    Step one, let all the air out and try and bottom it out a bunch of times to force the air from positive to negative. Step two inflate it to near max( rate max is 148, I inflated to 143), and then take it out and bounce hard on it. I did it for 50 times.

    My shop said that doing both of those things should take care of it. In my experience, I had to repeat the process a few times, although each time I noticed an improvement. If it still doesn't work, hit the LBS as you may need to send it back to RS. Good luck.

    Side note: how difficult was it to change the piston to go from 150->160? I'm considering it.

  3. #3
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    When you install the piston you have to make sure it is all the way against the stop as you insert it into the stantion. If you don't have the piston against the stop the trapped air will cause what you described.

  4. #4
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    Quote Originally Posted by allen mueller View Post
    When you install the piston you have to make sure it is all the way against the stop as you insert it into the stantion. If you don't have the piston against the stop the trapped air will cause what you described.
    Do you mean when inserting and tightening the bolts when reattaching the lowers? There seems to be a lot of ambiguity about this, some people saying you need to bottom out the lowers when doing this. Others say you need to keep the lowers extended.

    I changed my Pike from 150 to 140 and reattached the lowers when extended. No problems thus far.
    D

  5. #5
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    I installed the piston with it all the against the stop, but when I installed the lowers I pushed the lowers all the way to the crown to let the air out before bolting on. Should I have bolted them on extended?

  6. #6
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    Bonking ... not feelin' well

    Quote Originally Posted by tokarsky268 View Post

    Side note: how difficult was it to change the piston to go from 150->160? I'm considering it.
    It was something that I was considering for a while, it was easy to do, but obviously I got it wrong somewhere.

  7. #7
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    Quote Originally Posted by fdes View Post
    I installed the piston with it all the against the stop, but when I installed the lowers I pushed the lowers all the way to the crown to let the air out before bolting on. Should I have bolted them on extended?
    That's the $64000 question. I've been looking online and on this website, and I've found seemingly equal numbers of people on either side of the fence regarding installing the lowers.

    No one with any authority has chimed in on this (or if they have, their opinion wasn't strident enough to convince me they knew what they were talking about).

    Is there a way to reach Rock Shox to get a definitive answer? Even their Pike service manual is ambiguous. There's no phone or email on their website. Guess they're too big a company now to bother with such things?
    D

  8. #8
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    I couldn't find an answer either. What I did do is unfasten the air piston, hung the fork upside down und pulled down on the uppers. After a while I heard the for repressurize. I'm not at full extension yet, but I'm missing about 5mm, which is much better that before. I'm thinking that the slick honey on the seals could be making the seals a little stickier and that I might get full extension after a few rides.

  9. #9
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    Quote Originally Posted by fdes View Post
    I installed the piston with it all the against the stop, but when I installed the lowers I pushed the lowers all the way to the crown to let the air out before bolting on. Should I have bolted them on extended?
    When I did mine I put some air in to extend the piston all the way out before sliding on the lowers. So that may be the issue. If you think about it if the shaft isn't extended when you bolt it up and try to extend it back out a vacuum will be created. I've always assembled forks with the shaft extended and never had any issues.

  10. #10
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    Quote Originally Posted by allen mueller View Post
    When I did mine I put some air in to extend the piston all the way out before sliding on the lowers. So that may be the issue. If you think about it if the shaft isn't extended when you bolt it up and try to extend it back out a vacuum will be created. I've always assembled forks with the shaft extended and never had any issues.
    Thanks, Will definitely try that next time. makes sense regarding the vacuum, I think that was happening since everytime I would pull on the lowers they would return to ots non extended position. Now, for the last 5mm to extend if I extend it by pulling it does not return, so I don't think a have a vacuum effect left.

  11. #11
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    Great (and important) thread.
    Like others have said there's a lot of differing opinions on this. And the wrong way will have a negative impact.
    MBR mag says to fully compress in link below but honestly I'm not sure they're correct. I think it creates the vacuum effect stated above -- that it will actually suck down the fork a bit and you don't get full extension.

    How to perform a RockShox Pike service (VIDEO) - MBR

  12. #12
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    Quote Originally Posted by jon123 View Post
    Great (and important) thread.
    Like others have said there's a lot of differing opinions on this. And the wrong way will have a negative impact.
    MBR mag says to fully compress in link below but honestly I'm not sure they're correct. I think it creates the vacuum effect stated above -- that it will actually suck down the fork a bit and you don't get full extension.

    How to perform a RockShox Pike service (VIDEO) - MBR
    Yes, and if you read the comments section (there aren't many), lots of them say that compression of the lowers during attachment is wrong. So confusing.
    D

  13. #13
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    Quote Originally Posted by Daverino View Post
    Yes, and if you read the comments section (there aren't many), lots of them say that compression of the lowers during attachment is wrong. So confusing.
    Interesting. Just read the comments (have to go to the video on youtube, not on the mbr site). Many said this is wrong.

    Also bikeco.com had a video that essentially would do the same thing and they've removed it, so I wonder if they too realized the effect it created:

    It was here:

    "How To" videos and write ups to help you get the most out of your mountain bike riding experience. Tech Spotlight with PinkBike.com

    But when you click it:

    http://bikeco.com/rockshox_pike_burp-content.aspx

  14. #14
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    Well, I was actually following the MBR video step by step. They have both a servicing video and a tracel adjust video. Both compress the lowers. I have performed a lower service compressing the shock without issues, but maybe its ok if the air piston has not been removed. Will definitely try uncompressed next time.

  15. #15
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    My experience with the Pike was that when I compressed the lowers and then screwed the lower bolts - after 1 ride my stanchions were sucked in a 20mm. Inserted a zip tie thru the dust wiper, heard "hissss" sound and after that everything was like it should. Now I have more than 30 rides on it, works like a charm. The dust seals on the Pike are good and the fork is extremely sensitive to anything, probably to the vacuum created in the lowers.

  16. #16
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    Quote Originally Posted by fdes View Post
    Thanks, Will definitely try that next time. makes sense regarding the vacuum, I think that was happening since everytime I would pull on the lowers they would return to ots non extended position. Now, for the last 5mm to extend if I extend it by pulling it does not return, so I don't think a have a vacuum effect left.
    I Am currently having this problem on my 2014 Rockshox Pike, did you find the solution to it?

  17. #17
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    Haven't had the problem in a long time. Whenever my pike loses some travel I usually take a small tiewrap and insert it under the dust wiper. Generally clears out any trapped air.

  18. #18
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    Ya, it has full travel when pulled on, however once weight is applied 3-5mm doesnt rebound fully and Im left with about 155 mm of travel, then when pulled on it returns to 160 and stays there until more weight is applied. No vacuum pulls it back down. Will try zip tie again.

  19. #19
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    I just did the lowers on my 2016 Pike RTC3 - dust seals and foam rings, and my fork rests at 20%. If you pull up on the crown the most I can get out of it is 10%. When you pull up on it is spongy and returns back to 20%. In addition to this I noticed that my original preload was 70 psi and after I serviced I needed 80 psi to get the same sag.

    I did the zip tie trick and heard a hiss, but this did not solve the fork resting at 20% sag. Is the consensus that when performing the lower service you should tighten the bottom bolt with the fork fully extended? It sounds like the best way to achieve this is add a little preload to extend the fork before tightening the bottom bolt.

    Thanks

  20. #20
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    I always insert my lowers with some pressure on the air chamber, I do this on my RS Recon, my RS Pike, my friend's RS Reba and my friends RS Pike. Before installing the lowers I check if the shaft is fully extended, till this day I never had any problem.

  21. #21
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    Since my last post I redid the lower service, but this time adding preload pressure to the air spring before reinstalling the lowers. It is a little improvement, but still around 20% sag with the no weight on the bike.

    I took the bike to my LBC and they think there is broken/damaged seal in the air spring assembly so just waiting for a seal to replace. I'm confident this will fix the problem.

    Thanks for the help.

  22. #22
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    If you let all the air out of the fork does it sink down all the way into compression? If so, could be air in the negative air chamber.

    I know one thing that can cause this stuck down situation is air in the negative chamber, not equalizing with the positive chamber, often because of too much lubricant (SRAM honey) on the piston seal.

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