Why a dropper post at all?

Gone are the days when you had to dismount and manually lower the saddle before every trail section. The dropper post allows you to adjust the saddle height at the touch of a button while riding:

• Saddle down: More freedom of movement and control downhill.

• Saddle high: efficient power transmission when riding uphill.

Especially in technically demanding terrain, a dropper makes the difference – it is not a luxury, but a real safety feature.

Requirements for retrofitting

Before you buy a dropper post, you should check whether your bike is suitable for it:

1. Seatpost diameter

The dropper post must fit into the seat tube. Common diameters are:

• 27.2 mm

• 30.9 mm

• 31.6 mm

• 34.9 mm

Measure the inner diameter or look at the old support – the value is usually engraved there.

2. Installation height and stroke

Not every dropper fits every bike. Important:

• Total length and minimum insertion depth

• Stroke (how much the support can be lowered – usually between 100 mm and 200 mm)

Body size, frame shape and the interior of the seat tube play a role here.

3. Internal or external train routing

• Internal (Stealth Routing): The cable runs inside the frame – elegant, but the frame must be prepared for this.

• External routing: The cable is routed along the outside of the frame – easier to install and ideal for older frames.

Which dropper post is the right one?

Here is an overview of common models and what you should pay attention to:

Remote lever: operation on the handlebar

A dropper post is operated via a handlebar lever, similar to a shift lever. Modern triggers can be integrated ergonomically. Keep in mind:

• Compatibility with handlebar diameter

• Easily accessible position, preferably on the left side (if single drive)

Step-by-step: Retrofitting a dropper post

1. Remove old support
Take off the saddle, take out the seat post – done.

2. Install new droppers
Before inserting: apply some grease to the end of the pipe.

3. Install cable routing / cable
External: Route the cable along the frame and secure it.
Internal: Lead the cable through the frame – sometimes a bit fiddly, magnetic tools may be helpful.

4. Install the remote lever
Place on the handlebar and adjust to your own ergonomics.

5. Adjust & Test
Align the saddle, tighten everything, test the function – done!

Conclusion: Is retrofitting worthwhile?

Definitely!
A dropper post is one of the most useful upgrades for your mountain bike. It offers more control, more flow, and more safety – especially on challenging terrain. Retrofitting is easily done with a little DIY skill. And there's a solution to suit every budget – from €100 to over €400.

Bonus tip 💡

If your frame doesn't support internal cable routing, that's no problem! Many good dropper posts can be routed externally — ideal for older or classic hardtails.