Forum home Mountain biking forum MTB workshop & tech

Pivot bolt spinning, can't tighten or loosen it

xiudxiud Posts: 6
edited June 2018 in MTB workshop & tech
Hi!

I have a specialized camber evo 2014, and one of the pivot bolt is spinning freely. I cannot tighten it nor loosen it and I can see the end of the bolt on the other side spinning also. And since the bolt is not quite tight, there is a small gap between the rear triangle and the main frame.

Is there anything I can do? Local bike shop was kind of clueless about what to do with this.

Thanks!

The photo to show which bolt i'm talking about.
bottom_pivot_bolt.jpg

Posts

  • thistle_thistle_ Posts: 4,595
    xiud wrote:
    Is there anything I can do? Local bike shop was kind of clueless about what to do with this.
    On my bike the pivot bolts were installed with Loctite, although I was able to undo them.
    Is it causing problems? (e.g. play at the joint). If not don't worry about it.
    Don't force the bolt if it's aluminium - it will crack and will be a right PITA to get out and probably just as difficult to find a replacement.
  • xiudxiud Posts: 6
    The thing is that the bolt is moving, it is not stuck. It is as if the threads were damaged which cause me to be unable to remove it or tight it up (there is a small play)
  • 02GF7402GF74 Posts: 1,294
    Have you checked the bolt on the other side, usually the pair form one assembly, on one side there is a bolt that screws into a threaded tube which makes up the bolt on the other side.
  • xiudxiud Posts: 6
    02GF74 wrote:
    Have you checked the bolt on the other side, usually the pair form one assembly, on one side there is a bolt that screws into a threaded tube which makes up the bolt on the other side.

    No sadly there is nothing on the other side, only the end of the bolt that goes through!
  • kirkymtbkirkymtb Posts: 31
    Here's a useful schematic which, if not your exact bike, will be very similar.
    https://media.specialized.com/support/c ... 6_revB.pdf
    It might be useful. It looks to me as if 2 parts of the pivot bolt screw together but it's not absolutely clear.
    My MTB blog...https://wordpress.com/view/mountainbiker.home.blog
    Boardman FS Pro 2016. Whyte PRST 4 2004, Whyte JW 4 2004 :D
  • kirkymtbkirkymtb Posts: 31
    If I absolutely had to get it out I might drill into the spinning "bolt end" and screw a stud extractor into it. This would allow you to stop it spinning and unscrew the allen bolt from the other side. I'd want a good look at it and a long think before I did anything, though. Wouldn't want to wreck it!
    My MTB blog...https://wordpress.com/view/mountainbiker.home.blog
    Boardman FS Pro 2016. Whyte PRST 4 2004, Whyte JW 4 2004 :D
  • JBAJBA Posts: 2,707
    Both bolts screw in to a threaded tube to form the pivot.
    You need to hold the bolt on one side in order to tighten ir loosen the other side.
    From memory I think one is 5mm and the other is 6mm.
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Bird Zero Mk1 ¦ Giant Revolt Advanced 2 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • 02GF7402GF74 Posts: 1,294
    xiud wrote:
    02GF74 wrote:
    Have you checked the bolt on the other side, usually the pair form one assembly, on one side there is a bolt that screws into a threaded tube which makes up the bolt on the other side.

    No sadly there is nothing on the other side, only the end of the bolt that goes through!


    Hmmm, really? can you post photo of the other side.
  • JGTRJGTR Posts: 1,404
    The bolt screws into the swing arm, if it’s spinning the thread has stripped. I’d try unscrewing it whilst applying pressure on the opposite side, hopefully it will wind out.

    It’s quite clearly a single bolt that goes through the frame and screws into the swing arm on the other side, plus I’ve changed these bearings before on my old Camber.
  • 02GF7402GF74 Posts: 1,294
    It has to be single bolt to ensure the swing arm pivots on the frame, when frame is made, both parts are aligned then one hole is drilled. One bolt ensures the arts are aligned.
  • kirkymtbkirkymtb Posts: 31
    If you refer to the link to a schematic that I posted above it is actually clear that it cannot be a single bolt and thread in the frame. Look at the bottom right hand box. The pivot bolt varies in diameter so if it was a single bolt it would be impossible to remove (or fit in the first place). It must surely have an allen screw socket at both ends???? Is one of them blocked with cack? It just needs a professional bodger like me to have a go at it.
    My MTB blog...https://wordpress.com/view/mountainbiker.home.blog
    Boardman FS Pro 2016. Whyte PRST 4 2004, Whyte JW 4 2004 :D
  • JGTRJGTR Posts: 1,404
    kirkymtb wrote:
    If you refer to the link to a schematic that I posted above it is actually clear that it cannot be a single bolt and thread in the frame. Look at the bottom right hand box. The pivot bolt varies in diameter so if it was a single bolt it would be impossible to remove (or fit in the first place). It must surely have an allen screw socket at both ends???? Is one of them blocked with cack? It just needs a professional bodger like me to have a go at it.

    It’s a hollow bolt, it’s the hole in the middle that varies in diameter. Plus I’ve owned the same bike and having removed that bolt, I can confirm it is a single bolt.
  • JBAJBA Posts: 2,707
    Ah, yes. It looks like the design has changed since the last FSR we had in our house.
    The bolt (2A in the schematic) screws in to the right hand (drive side) chain stay.

    Apologies for any confusion my earlier post may have caused.
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Bird Zero Mk1 ¦ Giant Revolt Advanced 2 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • xiudxiud Posts: 6
    Thanks for your help guys. Managed to get the bolt out by inserting a rod on the other side and tapping on it. The bolt came out without much resistance. The threads of the bolt and my frame are in really poor shape. I'll see what I will do with that.
  • xiudxiud Posts: 6
    Just to close this post, I had to change the lower swing arm of my bike, the bolt and the bearings. The threads on the frame were too damaged to do anything that would have lasted.
Sign In or Register to comment.