Yeah, I figured this would be the response I'd receive. Thanks for the input.

I plan on getting the CAAD9 1 then immediately swapping out the 7900 drivetrain for some used 7800 stuff I got reallll cheap. Anyone looking to build up a bike with 7900 this winter and looking for a deal, drop me a PM.

My .02 worth.

I am a 200 pound rider and very fit at that weight. Just a big guy. I swear by my carbon post on my Aluminum Felt F-75. It has a carbon fork and carbon seat stays too. I first replaced the stock Al with an Easton EC70 but it cracked after a about a thousand miles.

Now I am running an Alpha Q carbon seatpost and have over 6000 miles on it with no problems.
I do think it helps dampen vibration on those long rides. I do lots of Centuries, sometimes 3 in a month and sometimes I throw in a Double Century.

Like most carbon components, the significant difference in weight comes with a group set. In other words, as far as weight is concerned, the 50 or whatever grams you lose by switching from aluminum to carbon is most likely going to be unnoticeable.

However, as far as I am concerned, there is a big plus side to the mental part of cycling when you upgrade components. One, knowing that you just spent a ridiculous amount of money for a new bike part is good motivation to ride. Two, knowing that you just <i>upgraded</i> your part is good in convincing yourself to turn that crank a bit faster!

I bought a Thomson Elite seatpost in 2008. I cant explain what it is, but my ride is more comfortable with the Thomson than with my stock carbon (probably carbon wrapped) seatpost which was a single clamp design and made the saddle come loose a number of times (including one sheared off bolt).

Expensive but recommended.

The benefits of carbon (if any) usually only apply to high-end components. Cheap carbon is often heavier and/or more fragile than similarly priced aluminum components.

See, that pucker in my rear was right!!! I really dont want a sharp broken carbon post stuck anywhere it shouldnt be stuck...................................



RD

On my old ti bike I had a Thomson. My new ti bike came with a Ritchey carbon seat post. I tried it for a few hundred miles and then swapped it for the Thomson on my old bike. The Thomson stayed because it gave a unitary feeling to my frame and seatpost.

Thanks for the feedback. I'm going to look into a Thomson.

Question - how do you measure seatpost setback (centre of post to centre of clamp)? It's not indicated on the post that's on my bike, but I think it's the correct amount of setback in that the clamp is in about the middle of my saddle.

I've broken two Thomson seatposts. TWO
I have also broken Easton EA50s, Easton EC90 and a few others.

That is the standard measure - center of post to center of clamp, but the real measure of maximum setback potential on a post is determined by the distance from the front of the clamp to the centerline of the post. The clamp length might be 3cm on one model and 4cm on another. The one with the shorter clamp could have the same setback value, but actually allow another 5mm of rearward movment. None of the Thomson models has as much setback as most traditional post.

One of the oldest standards places the front of the clamp close the seatpost centerline, so a 4cm long clamp would have 20mm of setback. My FSA posts have 5-12mm more setback than that.

Thanks for the info. I attached a photo of the bike with the post I'll be swapping out. I believe c-c is about 20mm. The Thomson setback is 16mm. Would you say these posts have comparible setback? I'm hoping that if I go to the Thomson setback I'll be able to dial in the saddle so my reach is the same, and the saddle sits nicely between the limit marks.

Good thing is that I should be able to sort this out at the LBS before getting the new post, but thought I would ask here to get an early indication if this is possible.

Dave, do you think setback is the way to go on all frames or just the compact/sloping TT bikes?

I have an Italian steel bike that is traditional geometry and it has a Thomson post. I'm wondering if I should use it or get a post with setback. Do they offer Al posts in setback or just mainly carbon ones? Seems silly to put a carbon post on a steel bike. (yes, I do know they make the Thomson with the odd angle, but I don't like the looks of those)

A carbon post alone is not a spectacular addition to a bike, or a big weight loss, etc. Its the sum of the parts that add up.

My bike is not light because it has a carbon post, its light because it has a carbon post and SLR saddle, Record Ti, carbon cranks, etc, etc. My bike doesn't have good vibration absorption from the carbon post, but it does have it from the post, the saddle, carbon and ti frame, tire choice, etc., etc.

The post is one part in achieving the whole.

The need for a setback post has nothing to so with compact geometry, it's all about the seat tube angle and that has not changed much over many years. I've got aluminum posts that are 25 years old and they all have setback. It's the little or no setback models that are relatively new and they are usually aimed at the MTB market, not for road bikes. The only exception would be the rare frame brand that uses an extremely slack STA. LOOK used to produce all of their frame with a slack 72.5 degree STA, but they gave that up about 5 years ago. Even back then it was common to use a 20mm setback with the slack STA.

I'm a firm believer in getting your weight back far enough to produce a proper balance over the saddle, that results in little weight on the hands and better use of your leg muscles, not just the quads. I know people hate to hear this, but you don't see many pro riders using posts with no setback. You're most likely to see a nonsetback post on a small frame with a 73 degree STA. There are a few brands with that STA, even in the small sizes.