Seatpost diameter - reduce (machining) down?

anyone had any experience with reducing the seatpost diameter.?
i.e.machining a 27mm post down to 26.4mm?
I'm after a campag twin-bolt 26.4mm post....but I have a 27.2 (or 27.0)..
I s'pose it depends upon the wall thickness; are 26.4's simply a reduced 27.0 when originally manufactured, etc.

Markyp

I wouldn't do it.

There isn't a great deal of material in a seat post, you'd be removing almost a third of it to reduce it down.

There's also no guaranteeing that your machining would be up to the task... you might introduce flaws that create weak spots, such that even if the material that remained was enough the structural integrity of the material was compromised.

Just spend longer on eBay waiting for the right part to come up

25.0 are easier to get....so there's always the option of a 25 with a shim I s'pose...

As Velocio says it can be dangerous to alter a seatpost thickness. You would have to turn it down on a lathe and this would also ruin the finish of a campagnolo post, also it would depend alot on the weight of the rider and the type of riding you were doing. I have taken .2 of a post in the past but would not want to go any further.

Wall thickness should be the same on all sizes and if anything thicker on the smaller diameter post. Also i think campagnolo posts are forged and the process of the manufacturing of the post is what makes the strength.

I would sell your 27.2 and get the 26.4

thanks for the advice....think I'll search for 26.4mm.
I have the saddle right back...so there would be quite a bit of leverage on the post.

What about 27.2 to 27.0?

If you can't force it in, then it doesn't go in.

if it doesn't slide in easily with a bit of greasing, then it doesn't go in.

ftfy

I'm fairly sure that's what I said.

Now where's my rubber mallet.

If you can't force it in, then it doesn't go in.

I've had a seatpost break. Notfun. Don't do it.