No. Domane bed R.

Well said and completely agree. If you think of the lunacy of the design. One bolt...a compression bolt uses friction laterally to control saddle tilt against rider forces in the same plane as the rider putting pressure on either end of the saddle. Plus and to your point this single bolt also is responsible for retaining the fore/aft position of the saddle rails and the very high torque...10 full ft-lbs on most puts a tremendous load on the seat seat rails...many carbon or hollow Ti. Simply an awful design. A ubiquitous 2 bolt is the opposite. Much lower torque with more reasonable saddle rail pressure for retention and a 2 bolt can't slip by design.
This isn't just a problem with Trek but with all manufacturers with single bolt.
If you look for a company with some discretion when it comes to frame design other than Specialized which has their carbon OSBB debacle they finally discontinued...look no further than Pinarello. They get it. All their frames with proprietary posts are 2 bolt. And they have dropped all press fit BB's for 2016 and gone with Italian threaded BB's which are rock solid.

In some ways Campy's old serrated single bolt post which were ubiquitous in the peloton decades back...I owned them and still have a Bianchi post of the same design....are better than a modern single bolt because the plane of the bolt is in opposition to saddle tilt unlike modern designs. Single bolt seatposts and on higher end bikes with proprietary post designs are pretty inexcusable.

Yep

Those old serrated clamps work great

Most modern ones I've found very fiddly

But then again it's almost set it and forget it

Well, all I can say is that the single bolt design on my Madone 5.9 never gave me an issue after I figured it out. Many years and thousands of miles on rough roads with no slipping at all. Even during the times I weighed north of 200 lbs. So that's straight truth from an owner, not Internet rumor or someone's opinion of the design. That said, the single bolt design enve seat post on my Lynskey was slipping pretty much on ever other ride on the same roads my Trek never gave me issues on. Go figure...

The Domane 4.3, the bike the Op is looking at, doesn't have the seat mast/seat clamp that everybody seems to be discussing. It's a normal seatpost.

I'm another owner and have had this discussion with my LBS who would tell me if they were having problems with Trek's seat mast....they just aren't a problem if you don't tighten the seat mast clamp too much. Use a torque wrench (which you should be using on a carbon bike anyway).

I love the bike industry. My 2004 Look KG386 has a 25mm post. The only downside (other than limited options at that exact size) is that typical saddle bag velcro is too long for such a small post diameter. I'm happy to see 25.4mm posts because that means with a quick ream from 25 to 25.4mm (frame uses an aluminum insert in the seat tube) I could have some really nice new seatpost options for my 'vintage' frame. I always wanted to justify the Look carbon 25mm seatpost but it was so much heavier than the American Classic post available back then.

The go figure part is the nuance behind of the design difference in single bolt post designs from different manufactures. Some are more prone to slip. In fact, Trek's may be prone to slip less than Specialized or Cervelo's or Giants. They are not identical. On a particular stretch of rough road that I would bomb on a fast group ride, my Specialized single bolt used to slip as well when torqued to 10 ft-lbs which is torque spec and hard to even achieve with an allen key.

The whole of bringing it up...is the design along with type of BB plays heavily into the enjoyment of the bike for some and not all but the overarching lesson is if you choose a bike without these features there is NO issue. It would be different if a better mousetrap didn't exist. There is a reason when the world champion Sagan rides a 2 bolt post..and Boonen who came in second in the rough road Paris Roubaix. Both could be on Specialized single bolt post but the reason why they opt for a 2 bolt are obvious...its much better.

Etixx and Tinkoff teams are using FSA seatposts because FSA is their sponsor for those components. They only use Specialized parts for proprietary stuff such as aero seatposts.

I ride the 2 bolt seatpost those guys ride. It is about the best in the industry in terms of weight, saddle retention with friendly flex. Many riders go off the grid if a given product isn't up to standard. FSA makes great posts, stems and handlebars...I ride their handlebars as well. Btw, FSA's SLK post isn't nearly as good as their Kforce light post...completely different clamp design and FWIW both are 2 bolt.

And I haven't said anything that contradicts that. But Etixx ang Tinkoff still use the FSA components due to contractual obligations. Whether they'd go with off-sponsor posts and masking tape if FSA didn't provide the two bolt design, that's anyone's guess. Personally, I don't think they would, as it's primarily a problem for the mechanics, not the star riders (unlike wrong saddle or bar shape, or a flexy stem, for example).

Yeah, because all I ever hear about in post race reports is how much Trek Factory Racing has problems with saddles slipping in races.

Yep, I honestly prefer a classic seat post over mast design but in fairness it didn't cause me a problem on the Trek, nor did the single bolt. And when I was testing a Domane for possible purchase it didn't worry me. But them I'm not trying to be like ol' Petey boy or any other pro. Enve told me to use friction paste on their seat post to solve the slipping. I just haven't got around to it.

That list of problems you have with the design indicates to me that you suck at using tools. This whole bit about the clamp sliding out of alignment on one side? That would only happen if the clamps were wide open enough for one clamp to slide off the rail. So only when changing/installing a new saddle, and again that would only happen if you really sucked at using tools. During fine tuning adjustments, that just doesn't happen. Saddle tilts when you tighten the bolt? Hold the flipping saddle with your left hand and tighten using the torque wrench in your right hand. And I've never had to bang on a saddle to get it to budge for fine tuning adjustments. Every single single bolt assembly on a Trek I've ever touched has not had any of the issues you mention. Over two years of building, working on, and selling Treks it comes to quite a bit. Just how many of these have you worked on?

And you guys say there are just TONS of posts online. I googled it and barely found any. Most posts are actually slipping saddles on the seattube, not the clamp assembly itself. And I'm pretty sure 90+% of the related threads on this forum are just Campag4life *****ing about a seatmast designed he's never even owned or used.

Yeah, I noted that in my first tirade, but I'm just taking the opportunity to call out Campag on his BS because I'm tired of it.

Who cares about the OP though, it's all about us!

[MENTION=88222]Campag4life[/MENTION], still waiting on you to clarify your "voice of the industry" tag beneath your username.

Understandable.

It's a weird thing to complain about, IMHO, because it really does seem to work fine.

I don't have problems with slipping, I have problems with setup and adjusting. It's pretty much impossible to get the same angle twice, or to get the angle you're shooting for, or to get the SAME angle on both sides. It's just terrible. Maybe if I had a team mechanic to fiddle it, I wouldn't have a problem with the clamp, either. (But the team mechanic would.)

Oh! Ad hominem! The last resort of the moron. Yes, I've only built houses and cars and synthesizers for the last 40 years, I clearly "suck at tools."

I get the feeling you've never actually seen, let alone worked on, one of these clamps, and you're literally just talking out your ass. If you were actually even vaguely familiar with the design you'd understand why the "simple" procedure you're describing simply wouldn't work with the clamp. Even TREK instructs you to "use a mallet to tap through the clamp with a 4mm hex wrench" to get the clamp to release. Yeah, that's precision. You're a weird kind of Trek Fanboi.

Worst. Clamp. Ever.

I've sufficiently explained my experience and background (including the fact that I OWN a Domane 5.9 and have posted pictures of the thing here). I could offer more, but you know what? You're not worth it.

Go ahead and continue to suck at using tools if you like.

EDIT: You know what? It's really not nice of me to say you suck at using tools. It's really childish, and I'll admit to that. However, I do not appreciate being called a liar.

It is still my considered opinion that you are simply lying so as to make an argument. You are one sad fella, buddy.

If you feel so inclined to out me as a charlatan, please feel free to look me up on Instagram under the same user name WalksOn2Wheels or Jonathan Whitney in Denton, TX on facebook. I'm fully transparent here. No hiding behind keyboards for me. We can even go on a ride sometime if you ever make it down to North Texas. I can even show you how to work on a Trek seatmast.

Alright guys, let's simmer down in here. This baby is on the verge of closure if we can't get back on topic.

Jeez, so unnecessary.

I will freely and openly admit to going too far by directly telling a forum member that he "sucks at using tools" was over the line. I apologize. In the end, I'm worrying way too much about someone else's opinion, but only because they present it as fact, especially when one particular member finds it necessary to drag it up every time someone types the word "Trek."

It's ok if you do not prefer the design and would avoid the purchase of said bicycle because of it. That makes perfect sense. It is not, however, a fact that it is the worst seat clamp ever (please stop the hackneyed Simpsons comic book guy impersonation). It is dragged up in nearly every Trek thread as if buying said Trek will nearly guarantee a slipping saddle. Just because a handful of people whine on the internet does not account for the thousands of satisfied end users who don't complain at every turn. If it was even half as bad as you guys make it out to be, the design would have disappeared years ago. Just look at the Emonda thread. Lots of happy Trek users and I don't think a single one has mentioned a slipping saddle (EDIT: Whoops, no. Campag already struck in that thread. So no owners of said design have complained in that thread). And going back to Trek factory racing: if it was nearly as bad you say it is, they wouldn't make it past the first cobbled section without having to fall back to the team car for an adjustment.

But hey, that's all fine and dandy. If you want to close yourself off to some great bikes, go right ahead. I have no vested interest. But please do not peddle your opinion as fact when people are seeking legitimate advice (though they probably made a mistake asking the 41 in the first place).

Again, anyone is free to look me up. My open invitation to go on a ride stands, thought I should warn you I suck at riding.