Found in the new VN issue, but some pics from the online article. Sorry, doesn't look like I can pull up bigger ones. 2nd pic is most troublesome, but you can maybe squint the key points. Added key notes. Maybe you "know all the answers", but if you're ever curious about quantitative data like me,,,
The winners in the vibration damping test, and the only ones under 0.6 G of acceleration, were the FSA K-Force Light SB25 carbon seatpost and the Specialized S-Works FACT Carbon post...
The poorest performer in this test, with more than twice the amount of Gs as the top three performers, was the Ritchey WCS carbon straight post.
How Seatpost Material Affects Vibration
The Ritchey WCS setback seatposts in carbon and aluminum share the same design and are both very lightweight relative to others in their class. When it comes to vibration damping, the carbon version outshines its aluminum cousin, albeit not by a huge margin—less than 0.1 G. Bottom Line: Carbon seatposts absorb road vibration better. Five of the top six posts in this test were carbon; the only aluminum post in the top six is built with pivots and an elastomer.
Damping: Setback vs. Straight
...Our test showed that having the saddle pushed back on a straight seatpost resulted in the rider being bounced around more than on a setback seatpost with the saddle pushed forward....Bottom Line: Setback posts offer more vibration damping than straight posts; how much more will vary by manufacturer.
Damping: Seatposts with Suspension Features
The Specialized S-Works FACT Carbon seatpost almost won the overall test, with the Cane Creek Thudbuster/ST and Cannondale SAVE both coming in the top 1/3 overall. Bottom Line: Suspension can save your ass. Of the top five seatposts for vibration damping, three of them incorporate suspension designs.
As you might expect, the Cane Creek Thudbuster/ST far exceeded the flex, both horizontally and vertically, of any of the other seatposts...Interestingly, the seatpost with the worst high-frequency vibration performance, the Ritchey WCS Carbon straight post, had the second-highest vertical flex reading, behind only the Thudbuster/ST...
Due to the fact that we measured flex at the tail of the saddle, the seatposts with the lowest flex numbers were all setback seatposts:
The stiffest seatpost, and the only one to register under 0.15 inch flex in either direction (and it did it in both) was the Thomson Masterpiece setback...
How Seatpost Material Affects Saddle Flex
We tested only one model in both aluminum and carbon, the Ritchey WCS. Comparing the two — both with 25mm setback — we find that the flex of the carbon model is greater in both the horizontal and vertical directions than that of the aluminum one. Bottom Line: Carbon posts deflect more than similar aluminum posts, which is good for big hits.
Flex: Setback vs. Straight
In all cases except one, both the vertical and horizontal flex on the setback posts were less than on the straight posts of the same make and model. That one exception was the Ritchey WCS Carbon: The vertical flex with the straight WCS post was indeed greater than that of the setback version, but the horizontal flex of the straight WCS was slightly less than that of the setback WCS, breaking an otherwise straight flush of straight over setback...
Flex: Seatposts with Suspension Features
As noted and expected, the flex of the Cane Creek Thudbuster/ST greatly exceeded that of all of the other seatposts. It is the only one in this test with pivots; it is designed to move a long way while others can only flex along their length. The movement of the Specialized post with the Zertz elastomer plug is quite modest; it finished in fifth in horizontal movement and seventh in vertical flex.
Ease of Saddle Installation and Adjustment
This was not intended to be a test of the ease of setup of the various seatposts, but given that we had to swap and quickly set up saddle positions on 14 seatposts many times over two days of testing, we learned some things about that as well. The Ritchey single-bolt design, once you figured out how to avoid dropping all of the little separate pieces, was by far the easiest and fastest to install and adjust.
Pretty much the only thing standing out to me is the Specialized post. That Zertz insert the real deal or is this a shill? Wonder how the post would perform is that insert was removed and just left the gap.Conclusion
In general, when choosing between a straight or setback post (if your frame seat angle doesn’t already dictate which one you must use to achieve your desired position), a setback post will give you greater pedaling efficiency and more high-frequency vibration damping, while a straight post will give you more flex on big bumps, lower weight, and a more jarring ride on high-frequency small bumps.
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.
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