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bigger seat post, smaller seat tube

Old 01-14-22, 08:55 PM
  #1  
madi4
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bigger seat post, smaller seat tube

I bought a wrong seat post size, itís 31.6 seat post. Is there any chance that I can use it on my 27.2 seat tube?
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Old 01-14-22, 08:56 PM
  #2  
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No
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Old 01-14-22, 09:09 PM
  #3  
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No
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Old 01-14-22, 09:57 PM
  #4  
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Just kidding.
You need a 27.2mm seatpost.
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Old 01-15-22, 06:22 AM
  #5  
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No
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Old 01-15-22, 09:07 AM
  #6  
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In case you missed it, No.
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Old 01-15-22, 09:57 AM
  #7  
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Just to make sure you didn't miss anything so far...NO.
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Old 01-15-22, 10:06 AM
  #8  
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Homina x3
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Old 01-15-22, 10:09 AM
  #9  
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You might be able to slide the 31.6mm post over a 27.2mm post but that would be silly.



But, again, no.
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Old 01-15-22, 10:40 AM
  #10  
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Sure. Just lube it up and push really hard.
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Old 01-15-22, 10:57 AM
  #11  
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Originally Posted by Kapusta View Post
Sure. Just lube it up and push really hard.
Nope, not going anywhere near that.
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Old 01-15-22, 12:35 PM
  #12  
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Originally Posted by Kapusta View Post
Sure. Just lube it up and push really hard.
A post like this makes it soooo hard for me to NOT get banned.
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Old 01-15-22, 12:50 PM
  #13  
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If this is something you bought new from a retailer, just return it for a refund or correct size. As you just learned, with bicycles, the general standard is there are no general standards. Confirm measurements for everything. Chains, tires, handlebars, etc.
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Old 01-15-22, 01:29 PM
  #14  
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by the way,

Welcome to BF!


To answer your question, No!

Get the right size and don't cause yourself future grief.
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Old 01-15-22, 01:44 PM
  #15  
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Go visit a plumber, they will make it fit.
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Old 01-15-22, 01:57 PM
  #16  
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Originally Posted by Kapusta View Post
Sure. Just lube it up and push really hard.
Oh boy...
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Old 01-15-22, 02:06 PM
  #17  
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I am going to disagree with everyone in this post and say YES but not in it's current form. You will want to melt it down to a more liquidious state and then use a funnel (one that can handle melted aluminum) and pour it in to your seat tube. Now of course you will need to pour carefully so you can still insert a proper 27.2 seatpost above should want to ride the bike.
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Old 01-15-22, 09:07 PM
  #18  
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If it's aluminum, OP could buy a $3000 lathe and cut it down to the right diameter.
It will then fit, although the wall thickness might make it too weak.
Originally Posted by veganbikes View Post
I am going to disagree with everyone in this post and say YES but not in it's current form. You will want to melt it down to a more liquidious state and then use a funnel (one that can handle melted aluminum) and pour it in to your seat tube. Now of course you will need to pour carefully so you can still insert a proper 27.2 seatpost above should want to ride the bike.
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Old 01-15-22, 09:27 PM
  #19  
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Originally Posted by madi4 View Post
I bought a wrong seat post size, it’s 31.6 seat post. Is there any chance that I can use it on my 27.2 seat tube?
The way to use it is to post it here as a trade for a 27.2mm. I have several new and nice vintage 27.2mm posts but only need a 30.8mm with a setback, so I am out but you never know and if you find one all it will cost is shipping. Over on the Classic and Vintage forum there is a trade thread that might catch someone like me with too many bikes and needs a big post for some reason. Welcome.
Almost forgot ,there is a long shot over on the Mountain Biking Forum there is a Mountain Bike Marketplace with a trade thread.

Last edited by easyupbug; 01-15-22 at 09:40 PM.
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Old 01-16-22, 04:12 AM
  #20  
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Originally Posted by Homebrew01 View Post
If it's aluminum, OP could buy a $3000 lathe and cut it down to the right diameter.
It will then fit, although the wall thickness might make it too weak.
ding, ding, ding we have the CORRECT ANSWER!!!
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Old 01-16-22, 09:32 AM
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Originally Posted by madi4 View Post
I bought a wrong seat post size, itís 31.6 seat post. Is there any chance that I can use it on my 27.2 seat tube?
As EVERYONE else said, NO. I once hand sanded a 27.2 post to 27.0 and it took forever. No way even 0.2 mm oversized would fit, let alone 4.4 mm oversized.
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Old 01-16-22, 10:26 AM
  #22  
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Don't listen to everyone else here! Go out and buy a tube expander from Harbor Freight. Seat tubes usually have enough material that they can safely be expanded by 4.5 mm.

OTOH, I don't expect even a newbie to buy that. The answer is still NO. Welcome aboard!
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Old 01-16-22, 10:49 AM
  #23  
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I think the OP has received a few great suggestions how to make this work.
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Old 01-16-22, 11:21 AM
  #24  
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Eddy could do it
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Old 01-16-22, 12:40 PM
  #25  
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If you return the seatpost to where you got it, especially with the saddle attached, your karma will be restored.
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