Sanding a seatpost to size?

[Gartenmeister]

Originally Posted by mtechnica

I've fit a greasy 27.2 post in a 27.0 frame without even doing anything to it but YMMV

Well, believe it or not this is actually the correct answer. Turns out the height markings on the post are a really thick paint, and the clampy part of the seat tube shaved this (paint) a bit, but otherwise its good to go.

Thanks to all.

[fogrider]

Originally Posted by Gartenmeister

Well, believe it or not this is actually the correct answer. Turns out the height markings on the post are a really thick paint, and the clampy part of the seat tube shaved this (paint) a bit, but otherwise its good to go.

Thanks to all.

Typically, a greasy carbon seatpost is not a good idea as it tends to slip. carbon paste is a good idea all the time, http://www.velonews.com/2014/12/vide...n-paste_355755

Additionally the idea of sanding a carbon seatpost is such a bad idea, I just don't know what to say.

[spinarelli]

On carbon I would not do it. It cannot end well.
Just buy a new post and sell the old one in the classifieds.
Maybe on aluminum post if you had access to a lathe, maybe, if you are in a pinch.

[onekgguy]

Not related necessarily but interesting nonetheless.

https://youtu.be/4TkjA41tJ78

Kevin g

[David Kirk]

I apologize if i missed it but........what material is the frame?

dave

[Gartenmeister]

It's steel, an old Bridgestone RB-2.

Question is answered and the post is in guys, thanks. It went into place with no sanding or scraping required. Did not grease it either, although there was a light coating in the tube. It is very, very snug- not exactly easily adjustable- but it should work fine. If it slips I'll add paste later- quite familiar with its use.

It is interesting that I got this carbon post in w/o modification as the frame in question will absolutely not accept any alloy 27.2 post (with good reason, its a 27.0 tube).

[ultraman6970]

Erased.

[Gartenmeister]

Originally Posted by ultraman6970

Erased.

Too bad; good comments-I can see the original in my e-mail. Thanks.

[FriarQuade]

The biggest problem is keeping the seatpost round and a consistent OD throughout it's length. Best to do this kind of a thing on a lathe.

[jumphigher]

I'm planning on doing the exact same thing in the next day or two, OP - 27.2 to 27. Will post my results. I think done carefully it will work just fine.

[ultraman6970]

Sorry, noticed the dude fixed the problem so why to left it there hehehe... either way it can be done but depends a lot of the seatpost, and since carbon seatposts are never 100% accurate to wet sand 0.1 out of the clear coat is not like a lot, the other way is just sand the seat tube using a exhaust pipe expander or a car cyclinder reamer tool thingy, 3 blades and not super expensive either... well gonna stop right there.

Originally Posted by Gartenmeister

Too bad; good comments-I can see the original in my e-mail. Thanks.

[Red Tornado]

I once had my LBS ream a seat tube out 0,1mm (0.004") so I could go from 30,8 to 30,9. I wanted a certain make/model but the mfr didn't have 30,8 available at the time and didn't want to force an oversized post in there. Seems like you got it figured out, but if the shop has a reamer or a hone it's easier to go that route than removing material from the post provided you're not opening it up too much to. Maybe 0,1 to 0,3mm IMO.

[firemanj92]

I've sanded a seat post as it was just a shy larger than the I.D. of the seat tube. It took a lot of trial and error to finally get it right. As someone else stated, "patience". But in the end it was a feeling of accomplishment.

-J

[jumphigher]

Well as promised I'm updating how my own seat post sanding project went. I did it this evening on an older Richey carbon () post I had. Basically I took several sheets of med grit sandpaper and sanded the post in a circular motion, below the portion that sticks out of the frame. It worked well, after I reached the required size I greased the post and inserted it into the frame. Alls good so far. I'll be riding the bike tomorrow and will report if anything gets weird.

[JWDR]

Originally Posted by jumphigher

I'll be riding the bike tomorrow and will report if anything gets weird.

Good luck and be careful sitting on that ticking time bomb. Why wont you just listen to all the experts here that this will end badly? I advise calling ahead to your local hospital to ensure they have your blood type on hand.