How to Install a Dropper Post

Getting Started

Many dropper posts are cable-actuated, meaning the raising and lowering of the post is controlled by a cable that is pulled by a controller found at the handlebar. Some newer dropper posts are electronically controlled and are controlled wirelessly; for these styles, skip to the final section of this article.

Insert the post to the preferred ride height. For dropper posts this is typically measured from the top of the seat collar to the rails of the post. Mark the post at this height. A few wraps of tape allows the post to stay in place without tightening the collar.

Remove the post.

Next, install the controller at the bar. There are a few different styles of dropper controllers, including rocker levers and electronic remotes. The most common style is a lever that is very similar to a shift lever. 

Cable-actuated dropper posts use standard shift cable to actuate. It’s important to know how the lever and post are designed in order to orient the cable. Some systems are designed with the cable end at the lever, and some with the cable end at the post. Consult the dropper post’s literature if you’re not sure.

No matter the style and orientation, most find it best to mount their dropper lever on the left side of the bar. Stand over the bike; test out the lever placement to make sure it does not interfere with your riding.

Some levers feature multiple bolt holes that allow for adjustment of lever position. Those may help you find a more comfortable position. 

Routing and Sizing the Housing

Droppers use compression-less shift housing or in some cases dropper-specific housing. Droppers do not use helically-wound housing as often found on brakes.

To determine the appropriate housing length, hold up the housing to the frame beginning at the lever and measure it against the frame section by section. Add about about 12″/30 cm to the end. This will give you more than you need, which will help with routing.

Once you have an appropriate piece of housing, route the housing through the frame, or outside the frame if you have an externally-routed dropper and/or frame.

If internally routed, the frame may have a sleeve that allows you to push the housing in one side and it will pop out the other. For bikes with open internal routing, it can help to use the IR-1.3. The most important tool for this procedure is patience.

Install a ferrule onto the dropper side of the housing and insert it into the mounting location on the post. Insert the post to the desired saddle height, keeping slight pressure on the housing at the front of the bike to keep it engaged. This is a balancing act between pulling the housing and pushing the post.

At the handlebar, hold the housing to the bar to mock up the correct length. Make sure there is enough housing to allow for sufficient rotational travel of the handlebars — ideally, as far as they will go if interrupted or 180 degrees if uninterrupted. You’ll also want to consider future changes to the bike like handlebar height, stem length or handlebar width. Be sure to leave some extra housing length if you anticipate the possibility of changing these components in the future.

Cut the housing at the appropriate length with a sharp cable cutting pliers like the CN-10. Hold the housing perpendicular to the jaws and squeeze levers quickly for a clean cut. Often the housing will deform from being cut — use a pick or awl to open the liner up. Install a ferrule on the end of the housing.

Before installing the cable, pull the post out of the frame while gently pushing on the housing. This will help keep it engaged in the post so it comes out nicely.

Installing the Cable (Clamps At the Lever)

Cable installation location varies by dropper post model. For systems where the cable installs through the lever and is clamped at the post, skip to the next section.

For systems that install at the post and clamp at the lever:

1. Some posts have a small adapter that needs to be installed below the head. Install this now.
2. Insert the cable into the housing at the seatpost and push/pull it all the way through.
3. Install the cable end into the seatpost. Pull the cable at the lever to seat the housing into the post.
4. Insert the seatpost into the seat tube to the desired height. Keep pressure on the cable and housing as you push the seatpost into the seat tube so that it does not come unseated.
5. Insert the cable into the dropper lever. Be sure the barrel adjuster is turned fully clockwise so that you have as much adjustment as possible.
6. Tighten the cable fixing bolt at the lever. Do not cut the cable just yet.
7. Tighten the seat collar to the recommended torque.
8. Test the system: actuate the lever and push down on the post. Check that the post drops, and release the lever. Then, push the lever, and be sure the post pops back up. Repeat this a few times.
9. Check for any deadband (movement in the lever prior to actuation of the dropper) in the lever throw.
   • If there is deadband present, loosen the fixing bolt, pull the cable and re-fasten the fixing bolt.
   • If a very small amount of deadband is present, use the barrel adjuster to take up cable slack.
10. Cut the cable (fairly short so it does not stick out) and install a cable end cap. An EP-1 can be a very handy tool here.

The post is now fully installed.

Installing the Cable (Clamps At the Post)

For systems where the cable installs through the lever and is clamped at the post,

1. Install the cable through the lever at the bar and then through the housing.
2. Pull the cable at the post to seat the housing into the lever.
3. Slip the seatpost’s cable clamp over the cable. Set the cable clamp’s distance from the housing end cap to roughly 15 mm. Some manufactureres include a gauge for this. Another method without measuring is to push the lever fully and hold the cable clamp as close to the housing end as possible and tighten.  If this distance is too short, the post will be actuated all of the time, and will not stay up. If this distance is too long, the post will not drop when the lever is pushed, and there will be deadband in the lever. Keep in mind that there is a barrel adjuster to accommodate some of the deadband. These can be found on the end of a noodle or on the actuation lever.
4. Tighten the cable clamp to manufacturer specified torque — typically 2 Nm.
5. Once you are confident with the length, cut the cable below the cable clamp using a diagonal cutter, leaving a very small amount sticking out. If left too long, the tail can interfere with the actuator’s function.
6. Apply grease or assembly compound to the inside of the seat tube. This makes for a cleaner install of the post compared to applying it to the post itself.
7. Slip the post back into the bike. While reinstalling the post, pull the housing at the nearest accessible section while pushing the post down to the appropriate height. This will prevent kinking of the housing. 
8. Once the post is at the preferred ride height, tighten the seat collar.
9. Test the system: actuate the lever and push down on the post. Check that the post drops, and release the lever. Then, push the lever, and be sure the post pops back up. Repeat this a few times.
10. Check for any deadband (movement in the lever prior to actuation of the dropper) in the lever throw.
    1. If there is deadband present, remove the post and adjust the spacing of the cable clamp.
    2. If a very small amount of deadband is present, use the barrel adjuster to take up cable slack.
11. When you are confident in the adjustment, tighten the seat collar to the recommended torque.

Wirelessly-Controlled Post Installation

The process for installing an wirelessly-controlled dropper is very similar to installing a standard seatpost. 

1. Prep the seat tube with grease or assembly compound.
2. Install post to desired ride height.
3. Tighten seat collar to the appropriate torque specification.
4. Charge the post’s battery. You may need to either remove the battery or plug the post into the charger directly.
5. Once the battery is charged, install the controller at the bar.
   • On a flat bar setup, these are typically installed on the bar like a shift lever.
   • On a drop bar setup, you may be able to use your shift levers to control your dropper or you may have a standalone controller/buttons.

You may need to sync the dropper with the controller. You may also need to make adjustments for your preferences using the manufacturer’s app.