[QUOTE=Fredo76;23168148]What do your calipers tell you about the ID of the seat tube? If it is 25mm as well, I'd believe them.

Thank you. I didn't measure the ID of the seat tube. I'll do that tonight. But I measured the diameter of the post itself, which came to 25mm. I used two types of calipers. I'll look on the post itself to see if it's marked with a measurement. I think I may be incorrect about the age of the frame. The link I provided was from a 2009 model. I think that I may have gotten the bike a year or two prior to that. It was likely made somewhere around 2006-2007. The frame specs probably stayed the same. As for the Thompson Elite, I think the smallest diameter is 27.2.