Help! Slipping Seatopst!- Mtbr.com
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  1. #1
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    Help! Slipping Seatopst!

    So I just built up a beater/commuter bike. Its an old nishiki road frame, pretty low end. It has an old chromed steel seatpost.
    enter problem.
    No matter how hard I tighten the seat binder bolt, I cannot keep the post from slipping. Any suggestions?

    Its a steel seatpost on a steel fame, could this be causing the problem?

    thanks for any help.

  2. #2
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    2 worth of thought....

    Quote Originally Posted by gspot
    So I just built up a beater/commuter bike. Its an old nishiki road frame, pretty low end. It has an old chromed steel seatpost.
    enter problem.
    No matter how hard I tighten the seat binder bolt, I cannot keep the post from slipping. Any suggestions?

    Its a steel seatpost on a steel fame, could this be causing the problem?

    thanks for any help.
    1. It's not the original seatpost and isn't sized correctly.
    2. The seatpost binder is the wrong size (unless of course, it's part of the seat tube).
    3. You can shim the seatpost with a cut up PBR can.

    Ken

  3. #3
    Am I getting too bulky?
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    Did you remember to grease it?
    I gotta roll, can't stand still, got a flame in my heart, can't get my fill.

  4. #4
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    I am 95% positive that it is the right size. The seat post fits fine, but slips when any wieght is added to it. (my arse) There is no room in the frame for a larger post, and the post firts fine without any play between the post and frame
    It is not currently greased, will that help it not slip? I would think that grease would make it slip more.
    thanks for your time

  5. #5
    Whiskey Tango Foxtrot
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    Surly's thoughts on the topic:
    http://www.surlybikes.com/spew4.html

    Entertaining, but let's hope it's nothing you didn't already know. Sometimes my nice Thomson post slips in my brand-new Santa Cruz, but then I just grease the threads on the QR bolt, tighten it a bit & I'm good to go.

    Surly's rant suggests you might need a new clamp; they also happen to sell them. Look closely at your clamp and draw the appropriate conclusion.

    Good luck.

  6. #6
    [email protected] da dumb
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    I used to have this problem with a steel frame and an aluminum (Thomson) seatpost. I got a surly constrictor binder and it seemed to help. Wipe off the grease on the seatpost shaft and clean the inside of the seat-tube.

  7. #7
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    Quote Originally Posted by gspot
    So I just built up a beater/commuter bike. Its an old nishiki road frame, pretty low end. It has an old chromed steel seatpost.
    enter problem.
    I had an old nishiki road frame Any way, I think it had a 26.8 seatpost (I will dig it out later and check) If that is the case, try getting a cheap alu-post (a kalloy comes to mind, I think I got mine at nashbar). The seat tube may be able to get a better bite on the aluminum post.

    edit: just dug it out of the bin, and it is a 26.6. The frame was from '85/'86
    Last edited by gpsser; 06-09-2004 at 07:30 PM. Reason: I checked
    "Life is a [email protected]#^ing story problem, get used to it - my son.

  8. #8
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    Quote Originally Posted by gspot
    It has an old chromed steel seatpost.
    Replace it with an aluminum post. Chrome is slippery - especially if greased.

  9. #9
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    Quote Originally Posted by eSSq
    Sometimes my nice Thomson post slips in my brand-new Santa Cruz, but then I just grease the threads on the QR bolt, tighten it a bit & I'm good to go.
    eSSq - careful not to go too tight. I've pinched in the back of a couple of T h o m s o n posts (thin walls) giving the clamp the old "tighten it a bit" move. Could cause the post to buckle back there if it gets pinched too tight.

  10. #10
    Medium?
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    Score it a little with a file.

    Make a scored pattern on the post in a diamondy kinda shape. Not deep or anything, just scuff up the chrome. Also, I'd <b>de</b>grease the seat tube.

    Aluminum posts are evil, and should be banned.

  11. #11
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    Make sure the binder bolt is greased. If it's not it might bind in the threads and then you wont be tightening it as much as you think you are.

    T

  12. #12
    KMA
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    I had the same problem with a carbon post and ti frame. The following worked for me and hopefully will fix your problem:

    1.) Clean the seatpost and inside the seat tube of the frame.
    2.) Put some chalk on the seatpost. I no longer have any seatpost slippage.

    Every couple months, loosen the seat binder and seatpost so it doesn't bind. Good Luck!

  13. #13
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    Pbr

    I like the PBR idea. I had the same problem with my bike. I was using a 27mm seatpost with a shim until I discovered my wife's bike had a 27.2mm seat post. I promptly swapped them out. Now she is asking why her seatpost is suddenly slipping and I tell her I have no idea why that is happening.

  14. #14
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    Quote Originally Posted by Chainwhipped
    I was using a 27mm seatpost with a shim until I discovered my wife's bike had a 27.2mm seat post. I promptly swapped them out. Now she is asking why her seatpost is suddenly slipping and I tell her I have no idea why that is happening.
    Low, man, low.
    "Life is a [email protected]#^ing story problem, get used to it - my son.

  15. #15
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    Quote Originally Posted by KMA
    2.) Put some chalk on the seatpost. I no longer have any seatpost slippage.
    Like climbing chalk? Sounds like a good idea. Thanks.

  16. #16
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    That would suck, but:

    1) My post is a big fat 30.9, and
    2) The fore and aft on my post is reinforced and thicker than the sides.

    Although, I am a fatass so maybe it will break anyway!

  17. #17
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    Quote Originally Posted by eSSq
    That would suck, but:

    1) My post is a big fat 30.9, and
    2) The fore and aft on my post is reinforced and thicker than the sides.

    Although, I am a fatass so maybe it will break anyway!
    Mine was too (31.6). It's thicker fore/aft, but I still managed to pinch a crimp in the post.

  18. #18
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    Wow. That would be annoying beyond words. You expect a thinwalled Ti post to fail eventually (except on a road bike), but a beefy T h o m s o n? Dang.

  19. #19
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    Quote Originally Posted by eSSq
    Wow. That would be annoying beyond words. You expect a thinwalled Ti post to fail eventually (except on a road bike), but a beefy T h o m s o n? Dang.
    Aye laddie, a beefy T h o m s o n. It's thicker fore/aft than the sides. However, I would reclassify that as it is thinner on the sides. Hope this turns out. It's not crimped big time, but enough for me to take my 170 lb hiney off it.
    Last edited by ssmike; 08-19-2006 at 08:04 AM.

  20. #20
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    New question here. Does your seat tube have a clamp?

    Quote Originally Posted by gspot
    I am 95% positive that it is the right size. The seat post fits fine, but slips when any wieght is added to it. (my arse) There is no room in the frame for a larger post, and the post firts fine without any play between the post and frame
    It is not currently greased, will that help it not slip? I would think that grease would make it slip more.
    thanks for your time
    Or is there just a couple of bosses welded on the tube that squeeze the top of the tube together. It sounds like a a combination of the chrome seat post and a weak clamp. If you don't have a clamp, many times the bosses will bend the seat clamp bolt and prevent the bolt from properly tightening the seatpost (a lot of time you run out of thread) . You may want to replace the bolt (try and find one with a big head); I like the chalk idea and ruffing up the post with a file. First make sure everything is clean; clean out the inside of the seat tube real good. A little good grease is good; old grease (remember grease if just oil suspended in wax) is bad. See if you can post a picture.

    1G1G, Brad

  21. #21
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    Here are some pics...

    Here they are.
    Attached Images Attached Images

  22. #22
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    Quote Originally Posted by gspot
    Here they are.
    Try a Campag seat binder bolt. You've got an excuse to use the best binder bolt. Try your local old roadie shop. There are several vintage road web sites that also sell them.

  23. #23
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    looks to me like the binder bolt is pinched together - ie: you've tightened it down so it's "hit the stops". Which would happen if the lugs on the frame sort of stretched a bit with age, or if the binder bolt was a bit too long.

    You could cut a little bit off the "nut" side of things, find a new shorter binder bolt, or use a bolt, nut and washers to clamp the post instead.

  24. #24
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    Quote Originally Posted by [email protected]
    looks to me like the binder bolt is pinched together - ie: you've tightened it down so it's "hit the stops". Which would happen if the lugs on the frame sort of stretched a bit with age, or if the binder bolt was a bit too long.

    You could cut a little bit off the "nut" side of things, find a new shorter binder bolt, or use a bolt, nut and washers to clamp the post instead.
    Good eyes Brant. Common modification as the width of the "ears" varies from frame to frame.

  25. #25
    KMA
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    Quote Originally Posted by eSSq
    Like climbing chalk? Sounds like a good idea. Thanks.
    eSSq - I used just regular chalk board chalk. Rubbed it on the post. It worked for my situation. However, I think Brant at On-One is right on about the binder bottoming out. He does indeed have a good eye.

  26. #26
    try driving your car less
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    Quote Originally Posted by aka brad
    (remember grease if just oil suspended in wax)

    1G1G, Brad
    really? wow, you learn something new everyday!
    gives me something to think about next time i eat greasy food.
    Only boring people get bored.

  27. #27
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    I had the same problem...

    ...on a recently built Ti SS with a 27.2mm Thomson post. I went to my LBS and they kept the bike for a day and brought in a special tool and notched my seatpost. It looks like little grooves in the post, much larger than the Thomson grooves and in a perpendicular direction.

    If needed, I can take pics and post one here. Let me know.

    It fixed the problem.

  28. #28
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    Please - take pics and post them. I'd love to see this!

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