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I just bought an NOS Ritchey Road Logic frameset. I have found that this frame takes a 27.0 seatpost. I have a Chorus titianium seatpost that I would really like to put on this bike. I wanted to get some opinions on whether it would be a bad idea to mill out the top of the seat tube 0.2 mm so the Chorus post will fit.
I actually did this on a lugged frame I built about 14 years ago. I don't remember the details, but on that frame I just milled the seat tube out untill the seatpost I wanted to use fit nicely. I've been riding that bike ever since with no problems.
But I'm not sure about doing this on a tig-welded frame such as the Ritchey. Any Ideas?
 

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Mahatma Kane said:
I just bought an NOS Ritchey Road Logic frameset. I have found that this frame takes a 27.0 seatpost. I have a Chorus titianium seatpost that I would really like to put on this bike. I wanted to get some opinions on whether it would be a bad idea to mill out the top of the seat tube 0.2 mm so the Chorus post will fit.
I actually did this on a lugged frame I built about 14 years ago. I don't remember the details, but on that frame I just milled the seat tube out untill the seatpost I wanted to use fit nicely. I've been riding that bike ever since with no problems.
But I'm not sure about doing this on a tig-welded frame such as the Ritchey. Any Ideas?
yeah, you might weaken the seat tube and that would be a bad idea. Thomson makes seatposts in a very wide range of diameters, I'm sure they have a 27.0. or you can find an NOS 27.0 somewhere. second best option: get a 26.8 (a relatively more common seatpost diameter) and get a thin shim.
 

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That's 0.00784" difference. I'd bet that if it's an older frame that has had the seatpost moved about a dozen or so times the 27.2mm post will slide in without a problem & would be as good a fit for the frame as a 27.0mm post would be.

If it doesn't fit, don't force it - you can have your LBS ream the frame with a hand reamer to accept the marginally larger post. That small of a difference in sizes is not going to significantly affect the frame.
 

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Dr. Paul Proteus said:
That's 0.00784" difference. I'd bet that if it's an older frame that has had the seatpost moved about a dozen or so times the 27.2mm post will slide in without a problem & would be as good a fit for the frame as a 27.0mm post would be.

If it doesn't fit, don't force it - you can have your LBS ream the frame with a hand reamer to accept the marginally larger post. That small of a difference in sizes is not going to significantly affect the frame.
If you don't want to alter the frame, how about just turning down the seatpost in the lathe? Or better yet, get the right size seatpost.
 
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