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  1. #1
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    Listen to my carbon mountain bike frame

    https://youtu.be/_2om1umYsaM

    Take a listen to that video and tell me what you think. Here is some background - new BH lynx 6 bike this year. Its been noisy the entire time I've owned it. Taken if down some pretty rough terrain and is riding really well, just a very noisy bike.

    I've tried all the low hanging fruit - torqued the seatpost to 4.5 nm, the handlebar/head tube clamp up to spec. Put carbon paste in seat tube and on handlebar clamp.

    I can hear it "pop" coming right from the frame about 1/2 way between handlebars and saddle on the horizontal piece of the frame. I can feel the pop right there when I put my hands on it. It always happens after I compress the rear shock and as it goes back into the resting position something seems to cause this pop right there.

    I pulled off the fork and looked inside the frame in the area where I think the pop is coming form and I dont see any cracking or delamination. There are no signs of delamination of the outside of the bike or other signs that the frame is failing.

    Everything that I read says that this pop is not normal and needs to be taken care of - is there anything else on the bike that I can rule out besides the frame itself and is there still a chance the bike/frame is OK?

    THANKS!!!!

  2. #2
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    I had a headset that got some sand in it that sounded much like your event. Perhaps....
    AKA: G-wat

  3. #3
    Interplanetary Poultry
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    Well, you could get a mechanics stethoscope and find the source of the sound that way.
    Editor In Chief, "Internet Tough Guy Magazine"
    "Home of Chuck Norris' Keyboard"

  4. #4
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    Since you bought it new it seems like a warranty issue.
    Warranty and Service: 949-206-8151, x135

  5. #5
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    Not sure I could hear what you described. I heard what sounds like a ratchet system when the bike goes back to normal position after the suspension is compressed. If you are saying there is a pop sound when you press down then I did not hear it.

    Anyway, as posted above, take it in for warranty.


    Sent from my iPad using Tapatalk

  6. #6
    because GIANT
    Reputation: 127.0.0.1's Avatar
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    yank seatpost out

    bounce frame , same issue ?
    "Put your seatbelt back on or get out and sit in the middle of that circle of death." - Johnny Scoot

  7. #7
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    Look at the shock pivots. They could be making a noise in that area. That's what's moving when the noise happens.

  8. #8
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    Quote Originally Posted by Len Baird View Post
    Look at the shock pivots. They could be making a noise in that area. That's what's moving when the noise happens.
    What should I be looking at on the pivots?

  9. #9
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    I’d be looking at interface between pivot bearings and pivot bolts. if any preload fasteners on your pivot bearings, check those. id also check cables. sometimes they are getting pulled or pushed through attachments points on frame which can make that sound or if internally routed they can be hitting inside of frame.

  10. #10
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    I think it's the shock pivots. I'd hose them down thoroughly with some sort of spray lube and see if goes away, if it does then go ahead and fix them right.
    I brake for stinkbugs

  11. #11
    ol' dusty lungs
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    Quote Originally Posted by attaboy View Post
    I’d be looking at interface between pivot bearings and pivot bolts. if any preload fasteners on your pivot bearings, check those. id also check cables. sometimes they are getting pulled or pushed through attachments points on frame which can make that sound or if internally routed they can be hitting inside of frame.
    ^ This. Pull your rear suspension apart. Make sure your linkage bearings are smooth and pivot bolts are tight. Also check your internally routed cables - place a few drops of dry lube like Triflow at entry/exit points and pull the cable back and forth a bit to distribute.

  12. #12
    Mr. Buck E. Fikes
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    Take the seat off the post and do it again. I'm putting my money that it's the rails where they interface with the carcass of the saddle. Just diagnosed the identical sounding issue on a friends bike I had in the shop here. Seat replaced, creak gone.

  13. #13
    All fat, all the time.
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    Quote Originally Posted by Oh My Sack! View Post
    Take the seat off the post and do it again. I'm putting my money that it's the rails where they interface with the carcass of the saddle. Just diagnosed the identical sounding issue on a friends bike I had in the shop here. Seat replaced, creak gone.
    X2 I've had similar noises from seat rail or even grit inside the frame

  14. #14
    Mr. Buck E. Fikes
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    WELL?!! Come on, OP! What's the skinny?

  15. #15
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    Sounds like a loose something. Start by methodically pulling apart and greasing/tightening each bolt/part. Eventually you will find the creak.

  16. #16
    Barely in control
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    Suspension bushings over tightened or in need of lube.

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