Fierte Seatpost Shim-Call Me Stupid

[Hawker]

I removed the seat post from my Fierte trying to figure out what type of carbon seat post I actually have (a Bontrager model I can't find on-line) and then realized there was a spacer so that the 27.2 post would fit a much larger seat tube. 30.9 I think. But now I can't remember how the spacer goes back in.

Would it be; spacer in seat tube and then the seat clamp over that OR seat clamp over seat tube and then the spacer inserted? Either option looks right but I have a feeling only one way is correct?

Thanks.

[bjf]

I would have thought that the Fierte was made for a 27.2 seatpost.

[Hawker]

Originally Posted by bjf

I would have thought that the Fierte was made for a 27.2 seatpost.

Nope, the seat post is quite a bit larger.

[weisan]

Originally Posted by Hawker

Nope, the seat post is quite a bit larger.

My Fierte uses the standard 27.2.
uh-oh, you got a counterfeit!

[DfCas]

Clamp goes first, then the shim, then the seatpost.

[Hawker]

Originally Posted by weisan

My Fierte uses the standard 27.2.
uh-oh, you got a counterfeit!

An entire counterfeit Fierte or just a counterfeit seat post? Thanks Buddy.

[Hawker]

Originally Posted by DfCas

Clamp goes first, then the shim, then the seatpost.

Hmm, frankly if I had to guess I would have thought the reverse. Thanks.

[rwsaunders]

From the way back machine with good old Pete...

https://forums.thepaceline.net/showthread.php?t=54428

[weisan]

Originally Posted by rwsaunders

From the way back machine with good old Pete...

https://forums.thepaceline.net/showthread.php?t=54428

Originally Posted by Cinci Jim

My 2006 Fierte IT is a 30.9 seatpost.

Just sayin' - maybe it changed...

Interesting...
https://forums.thepaceline.net/showp...82&postcount=3

[happycampyer]

Iirc the ti and iT Fiertes (as well as other ti and iT Serottas that didn’t have swaged tubes) used the same 34.9 mm diameter seat tube as a Legend or Ottrott but, because the the tube wasn’t swaged to reduce the diameter at the seatstay/toptube junction, one needed a shim to step the ID down to 27.2 mm. 30.9 mm seatposts weren’t as common in the early to mid 2000’s as they became later, e.g., with Moots’ introduction of the RSL in 2010. 30.9 mm seatposts tend to be stiffer than 27.2 seatposts, so while one could use one on a Fierte, I would have thought Serotta would have spec’d a 27.2 seatpost (and included a shim as oem).

[tv_vt]

I have a very early Fierte IT. Came with a metal shim in seat tube to downsize opening to 27.2. It sits right on top of the seat tube, underneath the seat post collar. To remove it and put it back in, the collar has to be off the frame.

After a few years, I took it out. I realized that a larger post would fit directly into the frame without need for the shim. Can't remember that diameter, whether it was 30.9 or 31.8 or whatever. If I pulled my seatpost, I could find out fast, obviously.

[Peter P.]

Originally Posted by tv_vt

I have a very early Fierte IT. Came with a metal shim in seat tube to downsize opening to 27.2. It sits right on top of the seat tube, underneath the seat post collar. To remove it and put it back in, the collar has to be off the frame.

This is how it's done with my Soulcraft, and I imagine is the correct way for the Fierte.

The spacer has a flange which rests against the top of the seat tube but doesn't overhang the O.D. of the seat tube. You slip the collar over both. And ideally, you offset the slot of the shim with relation to the slot in the seat tube so the slots do not align. It helps prevent road grime from entering the seat tube and is less likely to cut into carbon seatposts.

[pdmtong]

is the sequence in this discussion based on the fierte design or would apply generically to any shim in any frame for using a different post?

specifically I am wondering the applicability (or not) as to the 30.0 my peg requires and the aftermarket shim I am using to accommodate a more readily available 27.2 post. FWIW the clamp is on the frame then the shim inserted into the clamp then the carbon post post installed with carbon paste

[Brian Smith]

Originally Posted by happycampyer

Iirc the ti and iT Fiertes (as well as other ti and iT Serottas that didn’t have swaged tubes) used the same 34.9 mm diameter seat tube as a Legend or Ottrott but, because the the tube wasn’t swaged to reduce the diameter at the seatstay/toptube junction, one needed a shim to step the ID down to 27.2 mm. 30.9 mm seatposts weren’t as common in the early to mid 2000’s as they became later, e.g., with Moots’ introduction of the RSL in 2010. 30.9 mm seatposts tend to be stiffer than 27.2 seatposts, so while one could use one on a Fierte, I would have thought Serotta would have spec’d a 27.2 seatpost (and included a shim as oem).

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.

[Hawker]

As the OP, just wanted to say thanks and I've learned a lot. Bottom line for me is; my Fierte appears to be one with the factory spacer installed so I can use a 27.2 seat post. And even though both variations of how to actually install the shim seem to work (I've tried), looks like the way Serotta MEANT it to work is with the clamp on first and then the shim over top. That is not the way I would have thought was best...but I'm taking their word for it over my limited mechanical skills.

So, thanks again and hope I didn't open up to large a can of worms. And now I wait...for my Shimano C24 clincher wheels to arrive that I just purchased off Ebay. I believe they will serve the bike better than the entry level Bontrager set that it came with. I'm also keeping my eye out for a used 7900 compact groupset with 170mm cranks.