American Classic Seatpost: please educate me.
 

I have used AC seat posts before and had good results. The clamp is not the most sturdy design I've seen but it's not horrable either. In the grand scheme of things I would not let the seat post brand be a deciding factor in the purchase decision of a bike.

I weigh 210# and have AC's on two bikes. No issues. Gotta get the screws tight, though.

I've got two versions of the American Classic post.
For simplicity, I've referred to one as the 1st generation and the latter one as 2nd generation. There may have been a design change somewhere else within the life, and I know that the last version underwent a huge change and looked like a candy cane.


a shot of the 1st gen and 2nd gen, showing the tops of the plates. 1st gen on the left, 2nd gen on the right.
The 1st gen uses a single piece tube and head assembly, while the 2nd gen machines a separate head which is then attached to the tube.
Both use a single bolt that clamps the two halves of the clamp assembly down to the head. The 1st gen bolt has a hemispherical brass-ish washer to allow the bolt to pivot. The 2nd gen bolt has the hemisphere machined into the bolt.
Both use a set screw to set the saddle's tilt angle. The 1st gen set screw has a flat end on it that fits into a hemispherical recess in the bottom of the plate. The 2nd gen set screw has a bevel on the end.
The lower plates both have a hemispherical recess for the set screw. The 1st gen has a lateral stiffening rib on the upper side, while the 2nd gen has a smaller one on the bottom. Both have channels for the saddle rails to sit in, but the 2nd gen has shallower channels.
The upper half of the clamp didn't change a lot between 1st and 2nd gen.

https://live.staticflickr.com/4823/4...3b35ba_c_d.jpg


https://live.staticflickr.com/4902/4...e27326_c_d.jpg


in this shot, the 1st gen is on the right, and you can see a rubber plug that seals up the hole of the tube portion.
https://live.staticflickr.com/1964/3...9b675a_c_d.jpg


https://live.staticflickr.com/4823/4...724d93_c_d.jpg


https://live.staticflickr.com/4905/3...b082ca_c_d.jpg


The only issue I've experienced that that the set screw will cause a bit of deformation where it hits the lower plate. This reduces the tension on the clamp bolt, which then allows it to loosen.
The fix is to check the bolt tension regularly for the first xxx rides.

Will it handle a 220 pound rider? I'm 155 pounds, so I cannot offer any useful info on this.

I use a Brooks Swift saddle with titanium rails, and don't have any problems with bending. Not what will happen with a heavier rider.

I have 30 years of experience on these and am very happy with them. I've also heard that others have had problems. In fact, I asked for people's experiences on the I-Bob list nearly 20 years ago. Let me insert the text of the summary of that informal survey....

rider: 1 wt: 190 miles: 3000
saddle: "Brooks B17, Specialized Pro, WTB"
off -road alu or ti?: ti broken? No

rider: 2 wt:175 miles: 10000
saddle: "Flite, Terry Liberator, B17"
on-road alu or ti?: alu broken? no

rider: 3 wt: 140
post #1 miles: 50000
saddle: "Richey Vector, B17"
on-road alu or ti?: alu broken? no
post #2 miles: ?? saddle: ??
off-road alu or ti?: ti broken? No
comment: post is 12 to 13 yrs old

rider: 4 wt: 170
post #1 miles: 33000
saddle: "Turbo, Lepper, asst. Brooks"
on-road alu or ti?: ti broken? no
post #2 miles: 5000
saddle: "Turbo, Lepper, asst. Brooks"
on-road alu or ti?: alu broken? No

rider: 5 wt: 170
post #1 miles: 15000
saddle: "Fizik, B17, Specialized BG Pro"
on-road alu or ti?: alu broken? no
post #2 miles: 10000
saddle: "Fizik, B17, Specialized BG Pro"
on-road alu or ti?: alu broken? No

rider: 6 wt: 210
post #1 miles: 10000
saddle: Fizik Pave
on-road alu or ti?: alu broken? No
comment: racing.
Post #2 miles: 20000
saddle: "IscaSelle Dakar, Flite"
on-road alu or ti?: alu broken? no
post #3 miles: ??
saddle: Flite
use: track alu or ti?: alu
broken? bent cradle
comment: bent at same time saddle rail broke during seated sprint

rider: 7 wt: 155
post #1 miles: 45000
saddle: Turbo, Brooks Pro and B.17
on-road alu or ti?: alu broken? No
post #2 miles: 14000
saddle: B.17
on-road alu or ti?: alu broken? no



That ought to be enough to either inspire many questions, or shut down discussion entirely! ;)


Steve in Peoria

AC seatposts weren't anything special, in terms of aesthetics. They are very plain, without any flutes or any other details on them like found on other sestpost. What I think they were really known for is their strength, while at the same time, being quite lightweight.

I have one on my 1993 Trek 5900. It appears to be version 1, per steelbikeguy 's post. I think the post is titanium, if I'm remembering Trek's specs correctly. I've mostly used it with a Selle Italia SLS Kit Carbonio saddle. No problems. I weigh 150 lbs.

Thanks for taking the time to post that info, Steve in Peoria. That's a great record of use!

Thanks everyone for the help. There won't be much post exposed, so there's that going for me...

I'll post photos if it happens.

Let me just say that I did crack the lower part of the clamp/cradle on a first generation post. It was the "stamped" cradle that I believe was eventually recalled. I never weighed over 142 lbs.

In '93, I bought a C-dale T1000 for touring. The adjusting bolt (rear?) broke within a month (before trip) and the bike shop replaced it with a nice Syncros. Gary Duke (Dukes Cycle in Toronto) told me this early post was known to have this problem and AC were coming out with a revision, which they did. I was a heavy and hard rider at that time.

I have a later Ti version that I don't ride much and it's been just fine. Data points.

I have several in use on bikes in the fleet, mostly because they're quite lightweight and can usually be found for small money. That said, almost all have had the problem of the saddle rail bolt suddenly loosening up mid-ride. So make sure you bring a 4mm allen wrench with enough reach to get to that bolt! Actually, I usually just apply thread locker and call it a day.

The only Ti AC posts that I've seen are two piece - the shaft is Ti and the head is aluminum. You can see the color difference of the material in the post on this Ciöcc..

http://cycle.ciocctoo.com/cousins.jpg

.
...fwiw, I've never experienced a problem with them, and have used them on two or three bicycles that I bought used, that came with them. And I weigh more like 240#-250#.
But I have to wonder, if you can afford a Flite saddle, even at the used prices for those, why wouldn't you just replace the post with something a little heavier and more solid ?

I have no useful information to add to this thread, but...

Great Ghu, that Pelizzoli is jaw-dropping. Even next to that gorgeous Ciocc, it's a Sophia-Loren-level knockout.

And running Challenge 27s under Croce D'Aune Delta brakes, no less...

--Shannon

I remember installing a bunch and never being impressed with them, found them slightly annoying. But, they usually only popped up or were installed on fairly decent bikes to begin with. Worst case, toss the post and get something better, plenty of options available for not a lot.

@steelbikeguy Thanks for the great, informative post. I wasn't aware of the 1st/2nd gen differences. Any idea when the 2nd gen was introduced?

I've used them on a few bikes--only 1st gen I believe. The lightweight was definitely a big part of the appeal of these posts BITD, but I also like the relatively sleek and unusual design. They polish up nicely, too. I'm currently using one on my Merlin with a Flite saddle, and I weigh not much less than you. That said, I also had an AC on my race bike back in the 80s, and that one did eventually needed to be replaced due to loosening and, as I vaguely recall, some issue with the tension bolt.

Is this a show your American Classic seatpost thread? ;)
https://live.staticflickr.com/1722/4...fb60e5c3_k.jpgIMG_4125 by gaucho777, on Flickr

Yup, mine has slightly different tones between the shaft and head, which appear to be pressed together. The seat post shaft is very thin, much thinner than a practical aluminum seat post would be.

I'll try to photograph it in daylight, where the tone differences would show better.

Dude, that Merlin is a time capsule. That's the OG fork, right? I remember that long crown, but forget what it was. Vitus 992? S/R Litage? And a Merlin Ti stem. And what look like Superbe Pro "hidden spring" calipers on an otherwise D/A bike.

You are an individual of discriminating taste.

--Shannon

Thanks, @ShannonM :) The brakes are DA 7400, too, just not a great view. And yes, fork is original. As far as I can tell, the Merlin fork is nearly identical to the Tange Fusion fork on my Park Pre also from the same period.

I currently have them on two bikes, both were NOS ebay finds and had another one in the 90's with a Flite saddle. Not sure which generation. I never had problems and they are my favorite design, if they were still being made it's the only post I'd buy. I like how you can remove/reinstall the saddle and don't have to readjust the tilt.

https://i.postimg.cc/xdxP26Gh/004.jpg

My first AC seat post was purchased around 1990 for a new frame, and is what I call a 1st gen.
The second was probably purchased in the year 2000, also for a new frame, and is what I call a 2nd gen.
I bought another around 2003, when I needed a 27.4mm post for a 753 frame.
The last was purchased around 2007 when I needed another 27.4mm post for a frame that had some work done and the seat tube got a bit over-reamed, I think. It had taken a 27.2mm prior to the work.
Both of the 27.4mm posts were of the 2nd gen style with the separate post head.

I think there might have been a version prior to my "1st gen" version, at least based on discussions in the past. I don't recall any details, though.


Steve in Peoria

I have two (bought used from ebay). One on the Vitus and one on my Trek. My friends in the Cambridge Vitus Club have another that sorta circulates among them. Excellent ratio of cost to lightness. They're likeable just for that. But maybe more important, the two-bolt design makes it easy-ish to adjust saddle angle in small degrees. So for me they've got everything I need: lightness, low cost, and micro-adjustment. I will be happy if they do have a reputation for breakage - that will keep them cheap on the used market.

First time I saw one was on the Pinarello I purchased. it looked low cost but after checking it out and doing a query here, I gained some respect for it. I now have two. I don't remember on which bike the second showed up. It has a black head.
I was using on on the De Rosa but replaced it with a Chorus aero post. It was too short so replaced that with a Miche.

Just weighed the following on a scale that may be in error.
Campagnolo two bolt NR - 280g
Campagnolo Chorus Aero - 250g
AC - 200g

The AC has the longest post at 220mm head to end
NR - 180
Chorus - 160 but usable distance is 95 from the Campagnolo band to the end.

So the AC is lightest and the longest post.

Nice photo comparison and explanations, Steve!

Yes, there is an even earlier version with the top plate being silver and “curvy”, almost like a bare aluminum stamping rather than a machined part with paint/powder coat. I’d offer a photo, but that would require waking my wife, which would NOT be acceptable!

I’ve loved ‘em but realize that my frames (bike and body) need more setback than these. No problems, however, in over 38,000 miles with one-piece aluminum and a 2-piece TI shaft versions. I’ve never been over 180# so that data isn’t much help to the OP.

I've had several of them, and on two of them the bottom rail bracket had been reassembled backwards!
Instead of the angle set screw going into the dimple, the dimple was up front and the angle screw just pushed against (and put slide scratches in) the flat part.
I think that gave them a reputation for being unstable, but I liked it because the used seat posts came real cheap!