Fierte Seatpost Shim-Call Me Stupid

[happycampyer]

Originally Posted by Brian Smith

That's close, but not exactly correct. While the Fierte IT (and the Nove) used 1 3/8" seat tubes (close to 34.9mm) and the Fierte Ti did use constant diameter seat tubes and not swaged seat tubes, the Fierte Ti mostly used 1 1/4" (close to 31.8mm) seat tubes. On all Fierte IT with 1 3/8" seat tubes, the shim for use with a 27.2mm seat post was included with each frame. The aluminum shims worked well enough, but the most reliable part is no part, and I'd recommend a 30.9mm seat post if your frame will accept it, rather than the 27.2mm seat post plus the shim. Your seat tube slot will deform less after installation with the correctly-sized 30.9mm post and no shim than it will with the correctly-sized 27.2mm post plus the shim.

Thanks, Brian! It’s always great to get info from folks who were on the inside. I figured the tubes were all straight, but didn’t realize that some models would get a skinnier tube.

Regarding the idea of using a 30.9 mm seatpost, I would just note that, while that avoids the use of the shim, it could have an effect on ride quality. I believe VeloNews did a test of the stiffness of a bunch of different seatposts, and in general the larger diameter ones were stiffer. Whether one can feel the difference is an eternal debate, but it is something to consider.

Fwiw, I’m having Firefly make a 1” (25.4 mm) seatpost for my bike specifically for the extra compliance.