I’ve gotten a few requests for a recommendation for dropper posts for gravel bikes. For anyone who has looked into this, there aren’t many choices out there because the great majority are made for mountain bikes and the seat tube in mountain bikes tends to be in the 31mm range, not 27.2mm, which is what most drop bar bikes have.
My recommendation is the Crank Brothers Highline XC/gravel post. It has a 27.2mm diameter and comes in four lengths: 60, 80, 100 and 125mm and the 60mm version also comes in a short edition for use in smaller frames. This is the sort of upgrade I do advocate having your shop install. Getting the housing length correct is a bit of a logic puzzle but because the cable is trimmed at the remote it’s not insane.
The reason I recommend the Crank Brothers over any of the other options is because of its remote. It mounts on the bar below the left lever and can be released from the drops with your thumb or from the hoods with middle and ring fingers. None of the other remotes have quite this design and some of them mount on the bar top, which is awful. Even if you don’t buy this one, don’t buy one with a remote that mounts to the top of the bar. By the time I decide I need the saddle down I’m already in the drops, so moving my hand back up requires some otherwise unnecessary braking.
The post goes for $249.99. Crank Brothers offers a detailed installation guide but I recommend before ordering looking at their web site and taking some measurements on your bike, particularly the distance from the top of the seat tube or seat collar to the top of the saddle. That will tell you how long a post you can order and I recommend ordering the longest post you can.
This might sound daft, but my experience is that now that I have a gravel bike with a dropper post, I don’t like to ride a gravel bike without one. Further, once I got used to descending with the seat down on a gravel bike, I found that I no longer only lowered it on the steep stuff where it was absolutely necessary; I found I was lowering the seat for every significant descent. A lower center of gravity always feels better. Trust me.