Using smaller seatp...
 

[Closed] Using smaller seatpost in larger seattube.

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I have a carbon frame with a 31.8 seattube and I want to replace the seatpost.

My favorite seatpost that I have is a 31.6 carbon post. Will I have any problems using this in a 31.8 seattube. I have tried it in the frame and it moves about a little bit until the seat collar it nipped up. I am concerned that the small movement may damage the frame/post.

Or do I get a 27.2-31.8 shim and buy a 27.2 post to be on the safe side?


 
Posted : 13/10/2009 8:06 pm
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It's a bad idea.


 
Posted : 13/10/2009 8:08 pm
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make yourself a fizzy drinks can shim? just make sure it's trimmed back enough that you can't cut your legs on it.


 
Posted : 13/10/2009 8:10 pm
 ton
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27.2 in a 30mm frame...it is not a bad idea, it was advised by the designer......... 8)


 
Posted : 13/10/2009 8:10 pm
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Carlosg, I have thought about that and may give it a try but don't want a metal can shim dropping into the frame and not coming out.

ton, please expand on you comment 27.2 in a 30mm frame


 
Posted : 13/10/2009 8:21 pm
 ton
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got a 27.2 thomson in my new mm bop frame which takes a 30mm.
when used with a correct shim a thiner post offers a bit of comfy flex on a harsh stiff frame...


 
Posted : 13/10/2009 8:23 pm
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Time to find a shim then. CRC seem to do some cheap ones.
Thanks all for the help as I was a bit concerned about ruining a great frame but was hoping to be tight and not splash out on a new seatpost.


 
Posted : 13/10/2009 8:27 pm
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Carlosg, I have thought about that and may give it a try but don't want a metal can shim dropping into the frame and not coming out.

fold the top over a couple of times to form a lip?


 
Posted : 13/10/2009 8:32 pm
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or cut it neatly, very slightly trim the corners so that they are rounded and sandpaper all the edges. Have I done this before? . . . ๐Ÿ˜‰

Oh, and a little 3M spray mount adhesive will stop the shim from sliding down the seat tube (easily loosened with GT85 once you can afford a proper sized post).


 
Posted : 13/10/2009 8:34 pm
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"A special shim from the private stock of Baron Alfred Krupp, who had to sell it at a great sacrifice."


 
Posted : 13/10/2009 11:29 pm
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You want a coke can 0.1mm thick?

"It's a bad idea. "
I know I wouldn't, especially being carbon


 
Posted : 13/10/2009 11:34 pm