I was looking at this:

Race X Lite ACC (Aluminum Core Construction)
https://bontrager.com/model/04052

And I am thinking, besides the obvious bling factor of that carbon look, does that thin carbon layer actually provide a vibration dampening function? Sort of like when you wrap your hand around a vibrating tuning fork, your hand would quiet down the vibrations? I'm not a heavy rider (134 lbs), and am not a weight weenie, am just looking to take some vibration sting out of my aluminum frame road bike. I don't like the idea of a full carbon seatpost, don't want to worry about over-torquing the seat binder and crushing the seatpost. Forgive me for my paranoia, I try to avoid full carbon if I can. My other option would be to fork out twice the money and buy a titanium seatpost. But that's for another discussion thread.

I should add that it's a compact frame, and there's lots of exposed seatpost. Also, I've already improved the ride quality by upgrading to better wheels and using 25c tires. I'm now looking at the seatpost to incrementally better the ride quality. I'm a middle aged recreational rider riding between 50 to 100 miles a week, just so you know where I'm coming from. Much thanks in advance.

Not in my experience.

I dont know for sure but I would say there is virtually no dampening effect and the carbon is for show only. The load is still supported by the alum core. A full carbon post may not absorb road buzz as much as you think.

Velo recently published a test of seat posts, the conclusion reads:

When choosing between aluminum and carbon seatposts, our tests indicate that the carbon seatpost will offer more vibration damping on high-frequency bumpy surfaces and more flex for big bumps, while also being lighter; but they are more expensive.

From the pages of Velo: Getting the most from your post

No, they didn't test combo aluminum/carbon posts.

Much thanks, MegaTom, catonec, terrymorse. I was afraid that might be the case, thin as the carbon layer might be. I'll stick with my OEM aluminum seatpost then. Otherwise, I might just buy it for the bling factor if the urge to put something new on the bike becomes too great to resist. Eye candy, I know. Like seeing a new necklace on one's wife. Thanks again.

but you could get a full carbon seatpost for $100 really

sermour1910, thanks for that information. I just might get over my paranoia and do just that. I'll need to buy a torque wrench too, I haven't got one yet in the house.

Nope. There's no damping either.

Looigi, thanks for sharing your experience.

terrymorse, thanks much for that article link, I just finished reading it. I'm impressed with the thoroughly engineered testing they did. It concluded that there's less than 0.1 G difference in vibration damping between aluminum and carbon materials. And it says that any further vibration damping is due to seatpost design differences.

I also quote the article: "For a long road ride, the FSA K-Force Light SB25 post is our pick, thanks to its excellent vibration damping — it is noticeably more comfortable than an oversized aluminum post, especially on long rides, dirt roads, or concrete or asphalt with lots of small cracks and expansion joints."

Very enlightening. I will certainly reorient my thinking from hereon based on this study. This bike forum amazes me every now and then. Much thanks again.

Leonard Zinn does the testing for Velo. His engineering is pretty good, I subscribe to the print magazine primarily for his reports.

Addendum: Even though nobody asked, I'll reveal my favorite carbon post:

RITCHEY WCS CARBON 1-BOLT

The one-bolt seatpost clamp is the best part: easy to install and adjust, plus you can get adapters for carbon saddle rails. Not cheap, though, about $150 on sale. The Al version is much less expensive, but not as comfy.

see if you can win this one
https://www.ebay.com/itm/New-FSA-K-Fo...item4d08adba9f

My caad came with a full carbon seat post (no, it's not the wrapped one). I upgraded it to a full aluminum zipp and it rides the same or maybe a tad better. Certainly looks better.

which zipp did you get, I was thonking of going with zipp for seatpost, stem, and bars.

Service Course SL for bars, stem and post.

competitivecyclist.com has the ritchey wcs carbon seatpost on sale for $110. That's a really good deal.

Slight derail: My wife's old bike came with a carbon wrapped post.
I know not to put a seat post rack on a carbon post, but would one be safe on her aluminum wrapped post?

Speaking of seat post racks, I've been eyeing this intriguing design: Arkel Randonneur Seat Post Rack.



The problem with most seat post racks is that they cantilever off the seat post, putting some potentially destructive forces into the post. This Arkel design instead hangs off the saddle rails and merely rests against the seat post. That should allow this rack to be used on delicate carbon posts.

My daily commute requires me to carry a laptop and some clothing, which I've been stuffing in an Ortlieb backpack. But this Arkel rack matched with their TailRider Trunk Bag might make that commute a bit more pleasant. Pricey, though.