Ergon CF3 Pro flexing seatpost review

stay on the saddle all the time

Ergon CF3 Pro carbon seatpost has a very unique two leafs construction. This allows a lot of flex from the seatpost itself. And you can really feel it even when pedalling on a flat sections. For many this is a huge disadvantage but for me it is not a problem and you can really get use to it. Especially when advantages of having this kind of seatpost are so apparent.

Ergon CF3 Pro flexing seatpost (just like Canyon VCLS seatpost)

First thing you will notice while riding on Ergon CF3 Pro Carbon (or it’s Canyon VCLS 2.0 equivalent) is the somehow muted feeling of the road. As if you had a puncture. But after few more metres on a more challenging ground you will also notice that you don’t have to any more rise your butt to avoid bigger hits. You don’t need to do it because there is no more big hits. So you can stay seated almost all the time and focus on pedalling and finding the best route possible. This is a ground-breaking change that allows you to go faster for longer periods of time. Of course the more exposed the seatpost the more flex you will get. Also a variant with 25 mm setback (as I have) will offer you more flex than no setback version.

But the question is how much more comfort the flexing Ergon seatpost really provide? To find out I tested it alongside a more traditional FSA K-Force carbon seatpost which is famous for mitigating road vibration even in zero setback version (that I have). Riding on FSA K-Force subjectively is noticeably worse than on Ergon CF3 Pro. You can no longer stay seated and you can definitely feel the bigger hits on your butt.

Yet to my surprise the objective measurements showed that with tires at 40 psi (higher pressure of the tires allows the rest of the bike, especially seatpost to show its flexing abilities) Ergon post was in the forest better only by 9%. On the fast gravel route the difference was even less substantial – only 2,9% with 40 psi tire air pressure. When I lowered down the tire pressure to 20 psi the difference was bigger but still only 6,4%. Interestingly both times when tire air pressure was lowered the comfort improvement offered by Ergon flexing seatpost was bigger – it looks like it needs more travel to show it strenghts (which tire with lower air pressure provided).

Is this mean that a pricey CF3 Pro carbon seatpost is not that great addition to your bike when you want to improve the overall comfort? Not exactly. The case is much more complicated than that. First let’s check the Cervelo’s official chart describing what contributes to the overall ride quality at the rear of a drop bar bike  (https://www.cervelo.com/en/ride-quality). It’s tires. On the second place is saddle and only third is a seatpost. When you add another parts like shorts and frame (my bike is made from steel which adds a lot of comfort itself) you will notice that we can’t expect a miracles from changing just the seatpost itself. Especially on my test bike where I also use a very comfortable Brooks C17 saddle (which according to Cervelo is more important to overall comfort than seatpost and for sure I will try to verify this in near future).

Ergon CF3 Pro flexing seatpost (just like Canyon VCLS seatpost)

So can I recommend Ergon CF3 Pro carbon? Yes! Especially when your frame is not so forgiving (like stiff aluminium one). Just don’t expect miracles and still think of other factors that can contribute to the overall comfort – like lowering the tire air pressure.