Bianchi P.U.S.S. Seatpost Problem?!?!?!?- Mtbr.com
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  1. #1
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    Bonking ... not feelin' well Bianchi P.U.S.S. Seatpost Problem?!?!?!?

    I have a Bianchi PUSS and a 27.2 seatpost.

    I am able to 'wiggle' the post a bit when it is in the seat tube. While riding, it will make a creaking noise. I put in a beer can shim, but it still wiggled a bit and creaked. It does not slip at all in the seat tube. Also, it will move no matter how far the post is inserted, so I don't think the seat tube had expanded just where the end of the post is. It is almost like I should try a larger diameter post, but I'm 99% sure this frame takes a 27.2.

    Anyone else ever have this problem with their aluminum Bianchi SS? Very annoying and I only have this one bike!

  2. #2
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    I had a similar problem with my BUSS and a Thompson seatpost. I was using a Salsa seatpost Flick-Lock, and switching to a Hope seat clamp keeps the seatpost completely tight now. The Hope seat clamp has a taller collar and seems to have more leverage than the Salsa.

  3. #3
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    i actually cracked my seat tube right at the weld where it meets the top tube on my PUSS. Had it welded temporarily till my Siren gets built, but i did try to have it replaced and they were less than helpful. They only make 29ers now anyways, and i prefer 26".

  4. #4
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    Instead of a shim you might want to try a Thomson 27.4 seat post. Its just a bit bigger then the 27.2 and made for sloppy fits.

    Tim

  5. #5
    CB2
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    Take a micrometer to the seat post and the .i.d of the seat tube. Buy the appropriate shim or seat post.

  6. #6
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    Thanks for the suggestions.

    I was thinking about getting a Thomson 27.4. The beer can shim I tried should have added about .2mm making my current post a 27.4. It still wiggled a tiny bit before I tightened the seat clamp down. Then I went for a ride. Didn't hear anything for 10 or 15 minutes, but then it started creaking again for the rest of the ride.

    Regarding the micrometer, I'm not able to measure down inside the seat tube with the tools I have. I will try something.

    Econoline: I'm curious about your BUSS - before you have the hope clamp tightened, are you able to move the seatpost a bit side to side in the seat tube? I already have a Hope Q/R.

    I just got this frame used a couple of months ago and am wondering if it was made like this or if there is something wrong with it from use.

  7. #7
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    What length seat post are you using? If the ST is flexing, you might have stressed/cracked the weld. A longer 420mm(?) seat post is good insurance against this.

  8. #8
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    Itís definitely 27.2, and I also had slippage on my MUSS when I used a Salsa Flip Off Seatpost Skewer. I went to a Dimension Seatpost Binder Bolt and never had a problem since. Although I do get comments since I have mine so tight itís slightly bent, but it does the job nonetheless.

    On the subject of seatposts, recently mine started creaking but I think my old Easton EA70 post is fractured. I am about to purchase a Thomson seatpost and should be done with it (I use these on my other bikes and they are solid Ė the 2 bolt mounts are better than the one bolt Eastons IMO).

    So reverting to the subject of clamp, what are you using? Maybe with the beer shim and a binder bolt will solve your problem. Plus the Thomson post as previously suggested.

  9. #9
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    I don't have any up or down slipping whatsoever. Just the wobbling inside the seat tube. I can move it side to side and front to back in the tube. It doesn't matter if the post is inserted 50mm or the full 400mm - there is still some play.

    I've tried all combinations with a 27.2 x 410, a 27.2 x 330 thomson, a hope Q/R, a bolt on clamp, and the beer can shim.

    I need to try a 27.4 seatpost just for fun. This is driving me nuts!

  10. #10
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    fyi,
    The creaking on mine was the crack in the seat tube. after i had it welded, the creak went away. Not saying any of yours are cracked, but it's something to look at. My crack was microscopic, but it was definitely there (disturbing image, i know).

  11. #11
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    Quote Originally Posted by AZJP

    Econoline: I'm curious about your BUSS - before you have the hope clamp tightened, are you able to move the seatpost a bit side to side in the seat tube? I already have a Hope Q/R.
    My seatpost is 26.8mm, and yes, with the Hope clamp opened there is slight side to side movement of the seatpost within the seat tube. I have found that Thompson seatposts tend to run slightly small, and a 26.8mm Ritchey seatpost stays tight with the Salsa clamp. A Thompson 27.2mm seatpost on my road bike was so loose that I could not use it at all, but a Campy 27.2mm works perfectly. You might try another brand of seatpost and see how that fits.

  12. #12
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    Quote Originally Posted by Econoline
    My seatpost is 26.8mm, and yes, with the Hope clamp opened there is slight side to side movement of the seatpost within the seat tube.
    That is good to hear about your side-to-side movement. I've already had a few different 27.2's in there and they all wiggle a bit. Weird.

    I will also recheck very carefully for any microscopic cracks!

    Thanks for all of the replies.

    And here's the bike in question w/ 650b wheels and the kalloy seatpost:
    Bianchi P.U.S.S. Seatpost Problem?!?!?!?-img_0682_edit2.jpg

  13. #13
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    On the SASS steel models, what is the length of the seatpost binding bolt? I'm getting 1" outside edge to outside edge integrated clamp on the frame. Is what I'm looking for a binding bolt measuring 8 x 25mm closed?
    Creative Producer, Will of the Sun, Platform Pedal Shootout 1M+ views WoS

  14. #14
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    That's a nice bike not only because it's pink.

  15. #15
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    Quote Originally Posted by illnacord
    On the SASS steel models, what is the length of the seatpost binding bolt? I'm getting 1" outside edge to outside edge integrated clamp on the frame. Is what I'm looking for a binding bolt measuring 8 x 25mm closed?
    Nope, not 25mm you want a 22mm.
    Just one more rep and I get the toaster!

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