My verdict is that perhaps suspension seatposts are better suited for MTB/shorter rides where the constant variance in saddle position isn't such a big deal. Perhaps when seated and pedalling for long distances on a road-oriented gravel bike, the bobbing and movement just puts extra strain on knees?

Given that cyclists often have 60 to 70% of their body weight on their saddle, I don’t know if there is any other component that offers as much of an improvement in ride comfort (assuming you’ve already optimised your tyre width and pressure). Disfunctional_Threshold : I have the Syntace P6 Carbon Hi-Flex seatpost. I've never been able to detect any flex in it at all. Some riders, especially long distance racers, gravel riders and even tandem stokers like a bit of a suspension seatpost. Redshift makes one of those right now, which gives 35mm of parallelogram travel with a steel spring. (Apparently steel gives a smoother ride than elastomers in this situation, it uses elastomers for its suspension stem…) Regular dropper seatposts have very little vertical flex, which is an unfortunate consequence of their telescoping design. The seatpost offers the ability to switch the head around, offering more fit flexibility. Russell Burton / Our MediaThe Brooks C17 is a very comfy saddle that can flex a lot while you ride. But in combination with the Redshift seatpost, the Brooks shell was moving a bit too much for my liking. So I swapped it for a firmer saddle (Prologo Scratch RS) and it felt a lot better. Perhaps, spring-based seatposts work better with firmer saddles… The saddle installation is not easy due to the fact that access to the screws is difficult. I tried two different wrenches and still had a hard time accessing the bolts, and ended up scratching the seatpost near the screws. So choose your tools carefully! I also ran a suspension fork for this year’s event, and having a bit of front and rear compliance kept me fresh and comfortable, and allowed me to pedal through rough terrain.

I don't think d-shaped seatposts are standardised, so you'd need to look if there's anything specific for your bike.Here’s where it gets interesting though. I’ve been suffering from some knee pain recently from a noncycling incident, and thus have been spending a little more time seated while pedalling than I may have liked.

Then I built up a new gravel beast and thought, hey, why not upgrade the seatpost as well. I retired the Thudbuster and sprung for a Redshift (pun intended). I’ve been on it for a month now and there are no downsides. I’m 175# and this post is perfect. I run it slightly soft and it keeps me planted through the big hits and eliminates most of the medium chatter. Small stuttery garbage is gone. The return rate is immediate and so I’ve had no issues taking this bike on the concrete. Yesterday, on a whim, I took this bike on a group road ride and was in the front the whole time. I’ve experienced no penalty for running the Redshift post on the road! I used to laugh at people with suspension seatposts. Like a couple of commenters here, I felt it was an issue of proper seat adjustment and tire pressure. As a KOM-chasing, overly competitive maniac that frequently destroys equipment, I felt I was NOT the use case for these items. And what about long-term durability? Well, those elastomers definitely won’t last forever, although several years of regular use should be expected at the very least – and hopefully Redshift will keep replacements on hand for a long, long time. A bigger question mark is the pivots since they’re wholly exposed to the elements and much more difficult to replace, although Ahnert says that really hasn’t been an issue.The weight chart runs from 50-110kg, with riders over 90kg advised to use both springs, the smaller sitting inside the main spring when fitted. The system feels well-damped and there’s no noteworthy ‘bounce’ at any cadence. The saddle bottomed out a couple of times over bigger bumps; more spring compression might be useful off-road. I’ve only gotten four or five rides in with the new Thudbuster, but I’m quite impressed. The redesigned seat clamp is fantastic, and I found the new elastomer system to work very well. Unlike some of the softer, coil-sprung posts, the new Thudbuster offers a nice mix of chatter dampening and medium-hit suspension to take the edge off of sharper bumps. And, it doesn’t feel as if it has as much of an effect on pedaling efficiency as other, longer travel posts do. As we just saw in the test, if you’re riding on rougher terrain with larger forces coming from the rear wheel, you will benefit from more suspension travel as it can dampen more vibrations. I’d say most rough roads can be comfortably cycled with just 35mm of travel, but 50mm+ may be required if you’re hitting bumps at a higher speed (on an eBike, for example).