[41ants]

Just wondering if any of you have cracked your seat tube from the clamp. I have a thomson seatpost that just keeps on slipping. We are talking about every few miles I have to stop because it slipped a good 1/2 inch to an inch. Well, I cranked that mother F'er down nice and tight and I hear this crack/pop noise. This is a new frame and I am wondering how manufacturers would treat something like this.

 

[davedg]

It sounds like you have the wrong diameter seatpost.

 

[Schmucker]

What frame and what size post are you using?

 

[Bubblan]

...
I have a thomson seatpost that just keeps on slipping.
...

+1 on the Thomson seatpost slipping. Don't know but I've had problems with 3 different Thomson seatposts on 2 different frames. No other seatposts I've tried slips, but Thomson does.

 

[41ants]

+1 on the Thomson seatpost slipping. Don't know but I've had problems with 3 different Thomson seatposts on 2 different frames. No other seatposts I've tried slips, but Thomson does.

No problems when I had on on my Air9, One9, but it slips on my MCR. I have the correct diameter post and clamp. I am using a DKG clamp 29.6. In fact, I think DKG is the only one that makes one for the odd size that is required of the MCR. I am about to JB weld the thing and call it a day.

 

[funboarder1971]

When I bought my GT Peace 29er (new) it had a 26.8 post and it kept slipping. Someone had mentioned that these bikes shipped with the wrong size post.

Thomson 27.0 and problem solved!

 

[shiggy]

No problems when I had on on my Air9, One9, but it slips on my MCR. I have the correct diameter post and clamp. I am using a DKG clamp 29.6. In fact, I think DKG is the only one that makes one for the odd size that is required of the MCR. I am about to JB weld the thing and call it a day.

Get a different brand post. Thomsons tend to slip in some frames. Hopefully the "crack' you heard was the clamp and not the frame.

 

[mattKHS]

ive cracked a carbon post. it kept slipping and i kept tightening.

 

[PB Matrix]

Add a bit of dirt to the seat post, like just place your gloved palm in some dust and then rub it on the seatpost. Thomson's anno is slick so it needs a bit of friction material in between it and the frame.

 

[41ants]

Add a bit of dirt to the seat post, like just place your gloved palm in some dust and then rub it on the seatpost. Thomson's anno is slick so it needs a bit of friction material in between it and the frame.

Will give that a shot. I was a bit worried about Carbon with my weight and the amount of post that I have showing.

Update: It appears that all that broke was the bolt from the clamp and the clamp collar. Luckily the seat tube appears to be fine. Whewww! I was a bit worried.

 

[Megaclocker]

Will give that a shot. I was a bit worried about Carbon with my weight and the amount of post that I have showing.

Carbon paste + 60grit sandpaper on the seatpost.

Be sure to clean the inside of the ST before doing this. (oil or grease will make it slip)