27.2 or 27

[H.Frank Beshear]

I just got the Merckx Corsa extra and a 27.2 post seems a bit large. I tried a 26.8 and it fell in. Were the older corsa bult for a 27mm post? Thanks Frank

[stevep]

unlikely.
should be 27.2
needs to be reamed probably.

[swoop]

*bites tongue.

don't we all?

[Big Dan]

My Corsa 01 is 27.2.
fwiw..................
:cool:

[93LegendTG]

My 60cm Corsa takes a 27.0. I have been told that a seat tube built with Columbus SL required a 27.2 post while SP necessitated a 27.0.

[Too Tall]

that's dirty Swoopster...5 hail mary's pal.

27.0 fer sher. Call American Classic and talk to them. Not advertised but prolly avail. I can teach you the drill so you don't harm the adjuster...they are very good and inexpensive posts.

[chrisroph]

that's dirty Swoopster...5 hail mary's pal.

27.0 fer sher. Call American Classic and talk to them. Not advertised but prolly avail. I can teach you the drill so you don't harm the adjuster...they are very good and inexpensive posts.

2d the AC, good cheap posts.

[H.Frank Beshear]

This ones SLX and looks like someone may have over tightened the clamp at some time. 27.2 fits I did a bit of gentle persuasion and opened up the clamp a bit. Thanks all. I'll post some better pics after I get it built. Frank

[fogrider]

american classic is ok, but thomson is the best.

[Frank]

american classic is ok, but thomson is the best.

A few years back I was doing some maintenance on my road bike and found some dimpling on either side of my Thomson Elite seat post where it was clamped in the seat tube. I was concerned about the integrity of the seat post and returned it to Thomson asking them to take a look at it.

A couple of days later I had a phone message on my voice mail at home from Thomson. The fellow told me that the dimpling was not going to cause an issue as far as durabilty, but even so he was going to send me a new one. He mentioned the only time they see this dimpling on either side of the seat post is when a seatpost is the wrong size (trying to use a 27.2 in a 27.4 seattube) or when the seatpost is overly tightened in the seat tube and the seattube binder clamp digs into the seatpost. He asked me to make sure the seattube was indeed 27.2 before he sent me a new seatpost.

I did verify it was a 27.2 seat tube, and called them back and told them I may have tightened the seat tube binder too much causing the damage. They said they were going to send a seat post anyway and that it would not be necessary to crank down on the binder bolt as tightly as it sounds like I did as long as the seat post didn't slip or twist.

I had used them before that incident, but definitely since then I only use Thomson seatposts on my bike because of their strength, relatively light weight, and adjustability. Their excellent customer service gave me even more reason to stay with them.

[stevep]

overtightening seat binders= frequent problem on many posts.

use the tacx grease that introduces some friction into the grease to add a little holding power to keep the post from slipping.
fsa also markets this these days. good for carbon, alloy, any seatpost.

[Too Tall]

Oooo, good call SteveP :) I am a fiend for all sorts of prep. compounds and have a looong shelf, an idyl habit so it goes :rolleyes: Hey, a thumbs up for Thompson in general. I just got an stubby threadless stem from them for the custom stoker stem on our tandem and the design is pretty much over the top. Specs. on it are C.King good!!! Hey, now that's a new standard isn't it? CKworthy.