question about carbon seatposts.... I think I want one :)

[luckeeesmom]

So my aluminum bike rides a bit rough. From what I've read a carbon seatpost will probably help. What's the difference between the cheaper models vs. more expensive? Is carbon carbon or do the well known name brands make a better quality product? Also how do you know how much setback to purchase?

Thanks for any help I can get with this!

[DirtDiva]

The more expensive posts tend to be lighter. If you're after one for comfort's sake only, then you will probably be fine with a cheaper one. If your positioning on your bike is comfortable, then look for a seatpost with the same setback as the one you already have.

[luckeeesmom]

I took my current seatpost out and from the bike specs I know its 27.2 mm abd 350mm length but no details on the setback. I do know the there is setback but it appears to be a little less than the width in diameter of the seatpost so I assume that maybe it is approx 25mm or so. Is there any way to tell for sure? Thanks for your help! As for price, I'd like to get something on the lower range pricewise but the best quality I can get. I'm hoping I can catch a good deal!

[luckeeesmom]

Also are carbon seatposts likely to crack? what is their lifespan?

[Starfish]

Also are carbon seatposts likely to crack? what is their lifespan?

I would like to hear about this, too. I did read something on another thread where someone cracked their carbon post by over tightening it? I am thinking of getting one, too, but want to learn about how to keep it happy!

[OakLeaf]

I would like to hear about this, too. I did read something on another thread where someone cracked their carbon post by over tightening it? I am thinking of getting one, too, but want to learn about how to keep it happy!

Well, DH bought me a beautiful Snap-On torque wrench for Christmas. But I'll be able to use it when I get inside my m/c engine for a valve adjustment. I don't know if I'd spend that kind of money just for seatpost and stem adjustments (considering the number of seatposts you could buy for the price of the wrench)

Really, I would just trust that the shop got it right (probably too much to ask with some shops, but generally OK) - count the turns of the Allen wrench when you loosen it, then re-tighten by the same amount.

[Trekhawk]

I have carbon seatposts on both of my road bikes and I have not had any problems with them so far. My oldest would be coming up to 3 years of age.

Just remember that if you decide to buy anything that clips onto the seatpost read carefully if it can be mounted to carbon. I got myself a lovely hightail bag from Terry Bicycles for overnight trips on the bike but it can not be used with carbon. So I have an aluminium seatpost that I use for those rides.

[aicabsolut]

You probably have a standard setback seatpost already, so just stick with that. Use a torque wrench. Be sure the collar for the seatpost is the right size and that the post you buy is the right size for the frame (go with standard, standard, standard---no aero seatposts).

Don't attach anything heavy to the seatpost (like racks).

Otherwise, the only thing to worry about with carbon is that very heavy riders probably shouldn't use carbon.

[ehirsch83]

I just want to add a little thought here. I have had carbon and aluminum seat posts(I am one of the odd people who went from aluminum seat posts and bars to carbon, and now back to aluminum b/c I haven't upgraded those parts on the new bike yet).

Anyways, I don't notice the difference between the aluminum and the carbon seat post, where I do notice the difference is with the bars and vibration.
So before looking into a seatpost, I would weigh your options on handlebars(which I know can be more expensive) and a front fork if yours isn't carbon(definitaly way more expensive but makes all the difference).
A comfortable seat makes a 10x more noticable difference then a carbon seat post.

[VeloVT]

Also, before you invest $$$ in a carbon post, make sure you've done a good job researching both weight and adjustment mech on your chosen post. Some of the carbon posts are not all that light (over 200g) but are still $$$$ because they are CARBON. IMO don't spend the $$$ unless it's lighter. Regarding adjustment mechanisms -- it seems like the majority of carbon posts use one-bolt systems. There are well-designed and easy to adjust one-bolt systems out there, but the majority of them leave something to be desired as far as tilt-adjustment is concerned (and sometimes other things -- I once had a one-bolt seatpost for which you could ONLY adjust tilt by simultaneously adjusting fore-aft. BAD!). Make sure you either see the post before you buy it, or at least order something from LBS that they have seen & used. If you can find a two-bolt, light carbon seatpost that's in the budget, go for it (a lot of these are $$$$$$$$$$$$$$$$$ -- I think the Campy Record post meets all of these criteria, for instance).

Personally I'm a big fan of Thomson (aluminum) posts. Super easy to adjust and in the weight range of a lot of carbon posts. And no worries about over-tightening. But bf has a Bontrager carbon post (not sure what grade, race x-lite maybe?) that came stock on his 2007 Madone 5.2, and the one-bolt mechanism is very elegant and easy to use... No idea what it weighs or how much it costs though, and this would affect my decision if I were buying it after market.

[Mr. SR500]

I think they can make a slight difference, but not night and day. Torque wrench is highly recommended. Park makes a couple nice ones, also check Sears Craftsman.

Watch out for cheaper post, as they area carbon wrapped aluminum - so no benefit. The Bontrager (Trek) post are very nice, I run a Race XXX Lite on my Madone, and I've been very pleased. I also use a Campy Chorus on my Bianchi and it's an excellent post as well. I'm pushing 200 lbs, but don't have any problems.

[Duck on Wheels]

Also are carbon seatposts likely to crack? what is their lifespan?

Yep. Carbon seat posts do crack. I had one that lasted a year, riding moderate distances on mostly fairly smooth roads. I did hit one pothole a couple weeks before the seatpost snapped. That may have been a trigger. I've replaced the seatpost now. Not carbon, although the carbon post did make for a smoother ride.

[Trek420]

I was told not to get carbon on a steel frame. Is this true?

Something about it being more likely to crack. My steel road bike, all Campy Record has a Chorus seatpost because Record post is carbon. Oh the shame, the horror of non matching parts

But I like it fine.

[aicabsolut]

+1 for some carbon posts being a big pain in the ***, even for 2-bolt. Be sure you can get infinite tilt adjustment. As for 2-bolt systems, be sure that the 2nd bolt is easy access if you don't have a cut-out saddle design.

+1 for Thompson aluminum seatposts. Plenty of carbon devotees love Thompson posts. Probably the best seatposts out there really.

If you don't have a torque wrench (I don't yet..ooops), my LBS gave me a good rule of thumb. Wrench until it's fairly tight and then back it off a bit. There's no need to really crank the clamp on there, ever. It's got to be pretty loose for the post to do any slipping. I used the same rule of thumb when I had to move my FD as the shop had it set up all wrong and even if I had a torque wrench I don't know what the torque ought to be at that part of the seat tube.