Seat post bulge in seat tube.
Recently I read on sheldon brown's page that if a seat tube is improperly installed or too big that there would be a visible bulge at the top of the seat tube where the seat post penetrates the seat tube. Shortly After reading this I checked my bike and found a very slight warp (like sheldon the one was talking about) on the surface. This warp exists with the bikes stock seatpost. When purchasing my new shimano ultrega I made sure that it was the same size obv, but now I am feeling slightly reluctant to install my new saddle and seat post because I'm scared of the wear that it might cause to the frame. Is it possible that a manufacturer was stupid enough to shove a part to large into their own tubing? Is this a mistake on sheldons part? I feel a bit stupid posting this since I would consider my bike a beater, but it's just hard finding 64 cm frames, shes my behbey!
partly metal, partly real
Originally Posted by bonechilling
That sort of thing can also be caused by having your seat post over extended.
By and large, if it has been compromised, you can probably get away with running a seatpost that is long enough to engage the tube for a few inches below the damage.