Marking seat post for height adjustment.

Concorde wrote:

yeehaamcgee wrote:

You reckon seatposts don't snap? or frames, or handlebars or stems, or cranks?
REALLY?

No just no evidence for them snapping as a result of sanding a mark on the SP. Far morelikely to be a weakness in the making of the thing in the first place.

I don't know, I really don't. Because I haven't checked them all, and neither have you.
It's what's called an "unknown". And being unknown means that making assumptions may or may not be correct.

It's a case of "Just believing something to be so, does not MAKE it so".

Concorde wrote:

Yes but you can make educated guesses. Or to put it another way, be open minded but not so open minded that our brains fall out.

Riiiight. So. We KNOW that scoring metal (well, most materials) can start a crack propogating.
Yet you are arguing that even though we KNOW that, it doesn't happen?

I'm sorry, I just don't get your point. At all.

Concorde wrote:

No it happens. But scratching some paint off is hardly scoring metal. For god sake don't let that chain hit the chainstay on your ride will you, how many cracks is that going to start propogating??!?!?! Hundreds per ride maybe?!?!?!

Oh for the love of. Have you had a serious head injury recently?

What we're saying is that scratching your seatposts can have consequences. That's all.
It's not opinion, or hearsay, it's just a fact.

and how many Seat post are painted?

very very few they are anodised after bead blasting to remove any stress risers and area that may propagate cracks.

"sanding" a mark is a whole lot better as it is smooth and does not leave any stress points.

As this seems to be going round in circles.

Topic closed.