How to Choose the Right Dropper Post to Fully Enjoy Your Cannondale Topstone

I installed a dropper seatpost on my Cannondale Topstone gravel bike.

For me, a dropper post is essential as I sometimes ride trails on my Topstone. It has made riding even more comfortable and enjoyable.

However, there were several hurdles I encountered when installing a dropper post on the Topstone, especially during the selection process.

Not just any dropper post can be installed, so this time I'll explain the details.

This might be a niche topic, but please bear with me.

By the way, my Topstone is a size S, and the dropper post I chose is the BIKEYOKE REVIVE272.

This information should also be useful for installing dropper posts on smaller frames, not just the Topstone.

 

What is a dropper seatpost?

A dropper seatpost allows you to raise and lower your saddle with a lever operation while riding.

Since it can be operated while riding, there's no need to dismount to adjust the saddle height.

Recently, dropper seatposts designed for gravel bikes have become more common. 

Is it necessary for a gravel bike?

To be honest, it might not be necessary for most people.

But for me, since I sometimes ride trails on my Topstone, it's a must-have.

On flat terrain or climbs, I set the saddle to a height that allows for efficient pedaling. However, riding downhill sections of gravel or trails at that same height can be scary and not enjoyable. A lower saddle height provides more freedom of movement and confidence, making the bike easier to control and providing a greater sense of security. To descend dirt sections more enjoyably and safely, it's better to have the saddle height somewhat lower.

With a regular seatpost, you could stop and lower the saddle when you reach a downhill section, but if you're constantly going up and down, repeatedly dismounting and adjusting the saddle height is a huge hassle. Most importantly, it breaks the flow of the ride, which isn't pleasant. If you can operate it from the handlebars, you can change the height while riding without interrupting the flow of your ride.

If you want to fully enjoy dirt riding, I believe a dropper post is essential, just like for an MTB.

Of course, there are downsides, not just benefits.

1. Increased weight

　I prioritized the enjoyment of riding over the weight.

2. SmartSense rear light becomes unusable

　I love SmartSense, so it's a shame, but I prioritized the enjoyment and safety of dirt riding. I'm still trying to figure out if there's a solution.

Points to consider when choosing a dropper post

The Topstone has its peculiarities

The Topstone has Kingpin suspension in the seat tube, which limits how far a seatpost can be inserted. Therefore, there are size restrictions on the dropper post that can be installed. To avoid choosing a dropper post that doesn't fit and is unusable, here are some key points to remember.

I will use the BIKEYOKE REVIVE272, which I used this time, as an example. I will also explain why I chose this model and its key features.

Measure the necessary dimensions

As a prerequisite, a dropper post is installed by aligning the saddle top (from the top surface of the saddle to the center of the BB) with the fully extended state.

At that time, there are several dimensions that need to be measured for both the bike and the dropper post. Based on these measurements, you can choose a suitable dropper post.

The necessary dimensions are as follows:

Bike dimensions

※The saddle top should be set to your own dimensions.

・Dimension from saddle rail to the top end of the seat clamp (A)

・Maximum seatpost insertion depth (B)

The best way to measure this is by inserting a long seatpost as far as it will go.

・Seatpost size
The Topstone uses a 27.2mm seatpost. Naturally, you cannot use a seatpost of a different size than the frame.

 

Dropper post dimensions

These are the dimensions of the BIKEYOKE REVIVE272 in its fully extended state.

・Overall length (C)
The dimension from the saddle rail to the end of the seatpost. If the cable attachment protrudes, add that amount as well.

・Dimension from saddle rail to the bottom edge of the seal collar (D)
Dimension from the saddle rail to the bottom edge of the seal collar in the fully extended state.

・Lower tube dimension (E)
The maximum length that can be inserted into the frame. The dimension from the bottom edge of the seal collar to the bottom end of the seatpost.
Similar to (C), if the cable attachment protrudes, add that amount as well.

 

Based on the measured dimensions, select a model that meets the following conditions:

(A) + (B) > (C) and (A) > (D)

Furthermore, I wanted to utilize the maximum stroke, so I added the condition (B) > (E) to allow the seatpost to be inserted as far as possible.

Reasons for choosing BIKEYOKE REVIVE272

This time, there were 2-3 models that met my bike's requirements, but I ultimately went with the BIKEYOKE REVIVE272.

The deciding factor was that the overall length could be shortened.

And there are two ways to modify it.

1. The lower tube can be cut.

　You can cut up to 100mm.

2. The stroke length can be reduced.

　Although it requires disassembly, you can shorten the stroke by installing the included spacers.

 

If the dimensions don't match the conditions, you can adjust the overall length by combining either or both of 1 and 2 to meet the conditions.

For example,

・If you simply want to shorten the overall length (C), you can easily do so by cutting the lower tube.
・If the dimension (D) is longer than (A), you can resolve this by shortening the stroke.

This time, I was able to manage just by cutting the lower tube.

With the BIKEYOKE REVIVE272, I think it should be compatible with almost any size.

Furthermore, one major feature of the BIKEYOKE REVIVE272 is that it can quickly resolve air sag, which sometimes occurs, with just one tool. This greatly saves the hassle of disassembly.

Another dilemma

Besides the seatpost itself, another challenging aspect was the remote lever. The BIKEYOKE REVIVE272 unit does not come with a lever, so I had to purchase one separately, which wasn't as straightforward as with an MTB.

My criteria for choosing a lever were:

・It must be operable while holding the brake hoods.

・It must not be bulky.

If the drivetrain were a single front chainring, I could have repurposed the left-hand shifter as the dropper post remote lever, but I wanted to use a double front chainring, so I installed a separate lever this time.

I happened to find the crankbrothers HIGHLINE REMOTE KIT dropper bar lever, which seemed to meet my criteria.

I used this one this time.

I also had to experiment with the mounting position of the remote lever. For now, I've settled on a position slightly away from the brake hoods.

However, there's still room for improvement in the lever's position and feel, so it's likely to change as I continue to use it.

My impressions after using it

On downhill dirt sections, the increased freedom of movement has made riding much more enjoyable and confidence-inspiring. Also, on uphill dirt sections, there are many situations where lowering the saddle slightly makes climbing easier, and the dropper post handles this perfectly.
I am very satisfied with the results, which met my expectations.

Conversely, on paved downhills, lowering the saddle increased instability. While it does reduce wind resistance and makes you faster, it felt a bit scary. This was an unexpected result. On paved roads, it feels safer to keep the saddle high.

I chose to use the maximum stroke (80mm), but in practice, I might only need 30-40mm of travel.

There is still room for improvement in the remote lever's operation feel, so I want to continue using it and make it more user-friendly.

 

I don't know how many people are looking to put a dropper post on their gravel bike, but if you're interested, please feel free to contact us.