Advertise on

User Tag List

Results 1 to 2 of 2
  1. #1
    Join Date
    May 2008
    0 Post(s)
    0 Thread(s)

    Cracked paint or aluminum on my seat post? Pics

    I was cleaning up my bike and noticed a hairline "crack" on the tip of my seat post. It's a 2008 Bianchi Pista Concept track frame:

    The crack only appears on the exterior and I don't see any stress marks on the inside of the tube. I only ride this frame in the park and on the track.

    Anyone have any ideas?
    Last edited by lolroflmaoafk; 07-12-09 at 02:30 PM.

  2. #2
    Senior Member
    Join Date
    Apr 2009
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    152 Post(s)
    1 Thread(s)
    It could be simply a stress crack in overly brittle paint, but it looks more like it's in the metal. You might watch carefully to see if it widens when the clamp bolt is cinched, but the only way to know for sure is to remove the paint and check the metal beneath.

    If you're concerned and want decent post holding power with reduced stress, consider using coarse lapping compound (available in auto stores) in lieu of grease in the clamping zone of your post. The grit engages both the post and frame providing lots of holding power without having to tighten the clamp as much. (it's the same principle as throwing sand under tires for traction on ice)

    Good luck.

    BTW, if it is cracked, you can carefully file it down to a standard diameter, and fit a replaceable alloy clamp. It takes a bit of hand skill and patience, but isn't really difficult - a perfect DIY project to save a frame for little or no $$$.
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

Posting Permissions

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