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  1. #1
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    Lefty PBR 100mm (F-SI 2017 ALLOY1) knocking

    Hey guys! Recently, i was riding my new F-SI and after like 2 weeks of riding, i noticed knocking of my lefty when the fork is uncompressing the air (when it goes up). That knock appears in the top position of uncompression. So, i can reproduce that knocking by hitting breaks and compressing-uncompressing fork for 1cm.
    I've done reset but it doesn't solved the issue.
    Pressure in the fork is 115 psi. my weight is 75kg (pressure was chosen by measuring the sag in the sitting position).
    It seems not normal for new fork.. anybody knows what can it be and how can i fix it?

  2. #2
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    Lefty's are notoriously noisy, but I've owned several and usually the noises go away. (I realize that's not what you ant to hear). Do you have a 2Spring sticker on your fork? If not, you maybe broke the wavewasher, like all the rest of us have.


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  3. #3
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    Quote Originally Posted by Scott In MD View Post
    Lefty's are notoriously noisy, but I've owned several and usually the noises go away. (I realize that's not what you ant to hear). Do you have a 2Spring sticker on your fork? If not, you maybe broke the wavewasher, like all the rest of us have.


    Sent from my iPad using Tapatalk
    Yeah, all 2017 F-SI forks already with 2Spring update) (Interesting fact: i had problem with sag just after i bought my bicycle. You can read it here Lefty 2.0 (with 2Spring update) problem)

    Oh, i see, as long as it is within the norm - i'm cool with that (apparently, because there isn't much i can do about it ). Just want to be sure (understanding that to be 100% sure I need to SHOW the fork to a specialist) that it's not some kind of defect, which can lead to unforeseen consequences.

    Thank you for the reply)

  4. #4
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    The knocking noise at full extension is actually the solo air spring working! It's the noise the valve makes as it opens to balance the two chambers at full extension. It clicks when the valve closes as you compress the fork, too.

    If it stops making the noise at full extension...then you might have a problem

  5. #5
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    Quote Originally Posted by Howards View Post
    The knocking noise at full extension is actually the solo air spring working! It's the noise the valve makes as it opens to balance the two chambers at full extension. It clicks when the valve closes as you compress the fork, too.

    If it stops making the noise at full extension...then you might have a problem
    )) Strange fact is that from the beginning it was completely silent.

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