Dura Ace 7410 Seatpost cracked

[Foreigner]

Hi all,

resto project going on the 1992 TVT92 Carbone HM. Many issues, but progressing steadily

One of the pain points is the seatpost, which has two issues

No1 is stuck secondary seat pin at the back of the seat tube, I guess still and alu made permanent bond, so need to drill it out I guess, unless someone has other opinion?

No2 is a crack that split the top of the seatpost as per pics - guess has nowhere else to go or progress and kind of held together by a cradle, but still, your opinion is needed - change or keep? Can it be welded at all? Pitty as such a nice piece and also part of complete groupset.

 

[Nob]

For piece of mind & to be safe I’d be getting a new replacement.

Alloy welding is tricky business & you want to get it NDT dye pen or MPI after welding has been done...
Seek advice from properly certified alloy welders to see your options on your seatpost. Remember you will be sitting on it so need to know the weld won’t come unstuck when tearing downhill at 50mph++

 

[Foreigner]

Thanks Nob. I kind of guessed this will be the case but hope is always there

Why this has happened and if known issue is perhaps more important

 

[mdvineng]

Re:

Either caused by over tightening and or expansion due to corrosion.

 

[SimonJC]

Definitely change the seapost; consider that it is a component that is taking all of your weight, it is not something you want to use if any part of it has been compromised.
I have had issues with the Dura-Ace seatposts; I have a Dura-Ace 25th anniversary groupset, and have found the seatpost to be the only weak point with it.
The groupset is the 7700 series (9 speed) however as far as I know, and comparing it your pictures, it proves the seatpost is very similar in design.
My seatpost failed on the main post section, where it sort of 'detached' from the clamp section.
What I did was replace it with a Thompson Masterpiece, the name of the seatpost is a bit pretentious, but it really is of immense quality. The finish is perfect, and looks the part as well. I definitely recommend this post as a replacement.

 

[dyna-ti]

Anything cracked on a seatpost and it best consign it to the bin.

You understand the principle of an apple corer

 

[spitball]

Is that not just a 7400 seatpost? I thought Easton did the 7410 which has its own problems.

 

[Foreigner]

Is that not just a 7400 seatpost? I thought Easton did the 7410 which has its own problems.

Yes sorry 7400, have 7410 too and not same issue, well not same design either