Advertise on Bikeforums.net



User Tag List

Results 1 to 24 of 24
  1. #1
    Member
    Join Date
    Feb 2014
    My Bikes
    Specialized Langster and Cannondale CAAD10
    Posts
    37
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    How do I keep my seatpost from slipping?

    I was doing my first track race of the season, the cool ass mike race at encino velodrome. We were seated by flying 200. Coming out of turn 2 my seatpost slips and the nose points severely downward, i finished in 12.1. Throughout the matches it continues to slip. It is annoying me since it already has red loctite on it. The seatpost is one from the langster pro. How can I keep it from slipping because this can't happen at nationals.

  2. #2
    aka mattio queerpunk's Avatar
    Join Date
    May 2005
    Posts
    5,416
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Why is there loctite on it? Loctite is mainly for threading. Carbon installation paste would be a much better idea. Also, grease the bolts and torque them to spec. Try that and report back.

    I have a Langster Pro. No issues with the post - though I'm a featherweight.
    the hipster myth.

    i practice vagabondery.

  3. #3
    JMR
    JMR is offline
    Senior Member
    Join Date
    Feb 2008
    Location
    Australia
    Posts
    252
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Zero Talent View Post
    I was doing my first track race of the season, the cool ass mike race at encino velodrome. We were seated by flying 200. Coming out of turn 2 my seatpost slips and the nose points severely downward, i finished in 12.1. Throughout the matches it continues to slip. It is annoying me since it already has red loctite on it. The seatpost is one from the langster pro. How can I keep it from slipping because this can't happen at nationals.
    Carbon assembly paste and a torque wrench.

    Park Tool Co. » SAC-2 : SuperGrip? Carbon and Alloy Assembly Compound : Cleaning & Lube

    JMR

  4. #4
    Elitist carleton's Avatar
    Join Date
    Jul 2005
    Location
    Atlanta, GA
    Posts
    11,030
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    What bike and/or seatpost are we talking about?

  5. #5
    Member
    Join Date
    Feb 2014
    My Bikes
    Specialized Langster and Cannondale CAAD10
    Posts
    37
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Specialized Langster Pro. Venge seatpost. It's not the seatpost thats slipping downward its the nose of the saddle that is slipping. The problem is the single bolt holding it is not strong enough.

  6. #6
    Elitist carleton's Avatar
    Join Date
    Jul 2005
    Location
    Atlanta, GA
    Posts
    11,030
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Zero Talent View Post
    Specialized Langster Pro. Venge seatpost. It's not the seatpost thats slipping downward its the nose of the saddle that is slipping. The problem is the single bolt holding it is not strong enough.


    I hate those 1-bolt seatposts. I don't know if there is a good solution, but here's something that's worth a try: It's my understanding that the seatpost is reversible. Maybe put it in the forward position then jam your saddle all the way back in the rails, this will decrease the leverage the saddle has which is making it tilt. Hopefully, you can achieve the same setback.

  7. #7
    aka mattio queerpunk's Avatar
    Join Date
    May 2005
    Posts
    5,416
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Ah.
    Well, in which case, I blame the loctite you put on it - it is supposed to add resistance to threads turning, and may make it hard to tighten adequately!
    Disassemble the whole thing, and put carbon installation paste around the whole inner cylinder of the saddle clamp assembly.
    Remove the loctite from the threads of the bolt. Replace with honest, old-fashioned grease.
    Torque to spec.
    Live happily ever after.
    the hipster myth.

    i practice vagabondery.

  8. #8
    Senior Member Brian Ratliff's Avatar
    Join Date
    May 2002
    Location
    Near Portland, OR
    My Bikes
    Three road bikes. Two track bikes.
    Posts
    9,527
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Red loctite was a mistake. If you can get the bolt out again, find a new bolt and just use grease. Never use anything other than blue loctite if you ever want the bolt to move again.
    Cat 2 Track, Cat 3 Road.
    "If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter

  9. #9
    Senior Member Impreza_aL's Avatar
    Join Date
    May 2009
    My Bikes
    yellow tricycle di2 grip shifters
    Posts
    369
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    hairspray.

  10. #10
    Senior Member
    Join Date
    Sep 2012
    Location
    England, Great Britain
    My Bikes
    Tarmac/LangsterPro/Epic
    Posts
    259
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You guys do know that the 'saddle holding part'* of the post is alloy, not carbon?
    My Langster Pro slipped once, but after that (when I started tightening it properly), it's been fine. I was too gentle with it as I thought it looked a bit brittle.

    *If that thing does have a name, I can't think of it. The closest I can think of is 'saddle clamp'.
    Epic/Tarmac/Langster Pro

  11. #11
    Member
    Join Date
    Feb 2014
    My Bikes
    Specialized Langster and Cannondale CAAD10
    Posts
    37
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I can still tighten the bolt super tight ie 50nm. I will try the carbon paste and flipping it though. Thanks everyone.

  12. #12
    JMR
    JMR is offline
    Senior Member
    Join Date
    Feb 2008
    Location
    Australia
    Posts
    252
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Lew. View Post
    You guys do know that the 'saddle holding part'* of the post is alloy, not carbon?
    Yep, most assembly pastes will work on alloy too... the Park stuff I linked above specifies that it is for carbon or alloy.

    JMR

  13. #13
    Elitist carleton's Avatar
    Join Date
    Jul 2005
    Location
    Atlanta, GA
    Posts
    11,030
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    By the way, this is a known issue with that type of seatpost. I've know the Felt TK1 (older Ritchey) seatposts and the Serenity seatposts to have that problem. I've seen this design tilt under the smallest of riders.

    This is why I think Felt went with the 3T seatmast topper.

  14. #14
    Senior Member
    Join Date
    Jan 2006
    Location
    LI, NY
    My Bikes
    A little of each
    Posts
    317
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Those one piece bolts do require a higher torque than normal (usually 12-16 N*m), but I'm going to venture a guess if it's been torqued up to 50Nm, you'll probably want to replace that bolt. It's also possible that the conical wedge(s) slipping a few times has worn or smoothed down the mating area on the seatpost, which is making problems worse. If your shop is nearby, I would try to get them to warranty the seatpost assembly, and the next go around re-assemble with friction paste on those two surfaces and grease on the bolt threads.

  15. #15
    Senior Member Quinn8it's Avatar
    Join Date
    Jan 2008
    Location
    Hollywood
    My Bikes
    Bianchi Pista, Bianchi Vigorelli
    Posts
    673
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Currently every bike I own is built up with a Thomson post- and it's for a very good reason. There is nothing more annoying than seat post/saddle issues, and once you think they are fixed its always in the back of your head that it still is going to happen.. And it probably will.

    i wish more companies used standard post on track frames

  16. #16
    Elitist carleton's Avatar
    Join Date
    Jul 2005
    Location
    Atlanta, GA
    Posts
    11,030
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Quinn8it View Post
    Currently every bike I own is built up with a Thomson post- and it's for a very good reason. There is nothing more annoying than seat post/saddle issues, and once you think they are fixed its always in the back of your head that it still is going to happen.. And it probably will.

    i wish more companies used standard post on track frames
    You know I agree. The bike that I'm commissioning will also use a standard post (Thompson 30.9).

    It pains me to see that Dolan went away from this with the DF4.

  17. #17
    Senior Member Brian Ratliff's Avatar
    Join Date
    May 2002
    Location
    Near Portland, OR
    My Bikes
    Three road bikes. Two track bikes.
    Posts
    9,527
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by carleton View Post
    You know I agree. The bike that I'm commissioning will also use a standard post (Thompson 30.9).

    It pains me to see that Dolan went away from this with the DF4.
    The Dolan seatpost has a clamp based on the Thompson design. It is two bolts in a rocker pattern and doesn't rely on friction in any way. Since I got my Dolan Forza (similar seatpost as the new DF4 and identical clamp), I have been pleasantly surprised at the quality of the seatpost interface and the clamp. It is extremely well thought out. After two track sessions, no signs of slipping at all.
    Cat 2 Track, Cat 3 Road.
    "If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --the tiniest sprinter

  18. #18
    Elitist carleton's Avatar
    Join Date
    Jul 2005
    Location
    Atlanta, GA
    Posts
    11,030
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Brian Ratliff View Post
    The Dolan seatpost has a clamp based on the Thompson design. It is two bolts in a rocker pattern and doesn't rely on friction in any way. Since I got my Dolan Forza (similar seatpost as the new DF4 and identical clamp), I have been pleasantly surprised at the quality of the seatpost interface and the clamp. It is extremely well thought out. After two track sessions, no signs of slipping at all.
    Sorry. I was referring to using a non-round shaft.

  19. #19
    JMR
    JMR is offline
    Senior Member
    Join Date
    Feb 2008
    Location
    Australia
    Posts
    252
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I know that they tend to work better, but seeing a beautifully shaped, aerodynamic track frame with a standard round seatpost just breaks my heart.



    JMR

  20. #20
    Senior Member Velocirapture's Avatar
    Join Date
    Dec 2012
    Location
    South Africa
    My Bikes
    S-1 :-D
    Posts
    219
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Zero Talent View Post
    I can still tighten the bolt super tight ie 50nm. I will try the carbon paste and flipping it though. Thanks everyone.
    Are you sure you are actually tightening the bolt to that enormous torque,? Maybe the torque you are applying to the bolt is possibly still not actually moving/ tightening it, due to the red loctite? Your torque wrench will show as much torque as you apply..
    Last edited by Velocirapture; 04-01-14 at 12:21 AM.
    "All this talk of climbing is making me feel kinda queasy..." -- Baby Puke

  21. #21
    aka mattio queerpunk's Avatar
    Join Date
    May 2005
    Posts
    5,416
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Velocirapture View Post
    Are you sure you are actually tightening the bolt to that enormous torque,? Maybe the torque you are applying to the bolt is possibly still not actually moving/ tightening it, due to the red loctite? Your torque wrench will show as much torque as you apply..
    exactly my thought. instead of actually bringing the pieces together, those 50nm could just be grinding through the loctite.

    that's why we use grease on bolts. when there's a greased interface it allows pieces to move against each other, which lets them get tight enough to hold.
    the hipster myth.

    i practice vagabondery.

  22. #22
    Senior Member Quinn8it's Avatar
    Join Date
    Jan 2008
    Location
    Hollywood
    My Bikes
    Bianchi Pista, Bianchi Vigorelli
    Posts
    673
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Pretty sure that's how babies get made also

  23. #23
    aka mattio queerpunk's Avatar
    Join Date
    May 2005
    Posts
    5,416
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Depends on the interface used.
    the hipster myth.

    i practice vagabondery.

  24. #24
    A little North of Hell
    Join Date
    Mar 2006
    Posts
    4,363
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Specialized post

    Zero issues with my Specialized seatpost.
    Make sure it is assembled correctly.
    [SIGPIC][/SIGPIC]
    XXXI

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •