Suspension seatposts are… controversial.
Depending on who you ask seatpost suspension can be either a crafty solution for riding comfort or a waste of money which can cause you injury.
Why is the humble bike seat suspension system so divisive? Well, your experience with a suspension seatpost can vary wildly depending on your riding style and priorities.
So in this article, we’re commencing court, allowing both sides to have their say in a balanced evaluation, as well as recommending the best suspension seatposts available. So read on, we’ll be covering:
- What Is A Suspension Seatpost?
- How Does A Suspension Seatpost Work?
- The Pros Of A Suspension Seatpost
- The Cons Of A Suspension Seatpost
- Should I Buy A Suspension Seatpost?
Let’s dive in!
What Is A Suspension Seatpost?
A suspension seatpost is a shock absorption system that is mounted between your seatpost and saddle.
Like any suspension system, seatpost suspension partially absorbs forces from the point of contact carried through your bike into your body.
Research tells us that a cyclist places roughly 60% of their total body weight on the saddle, and a suspension seatpost dampens high-frequency vibrations and partially absorbs impacts carried through the saddle when riding.
How Does A Suspension Seatpost Work?
Suspension seatposts create travel below the seat by employing various systems of shock absorption that allow the seatpost to compress along its own axis.
There are two types of bike seat suspension designs: Parallelogram (or Linkage Driven), and Teloscopic.
Telescopic systems are fairly simple, usually using compressed air to allow the seatpost to compress along its own direction.
Parallelogram seatposts are more complex, using a flexible joint to allow the seatpost to arc against the direction of forces carried through the bike, which is better for absorption.
Parallelogram seatposts are more effective than Telescopic seatposts.
Parallelograms are more expensive, but their arcing design allows them to better absorb forces, while also maintaining a more consistent saddle height in compression, which is better for a few reasons which we’ll talk about in seatpost suspension pros.
Teloscopics are cheaper and lighter than parallelograms, however, they are less effective at absorbing forces and also create greater travel in the saddle, which is a problem we’ll talk about in suspension seatpost cons.
There are three types of damping systems that suspension seatposts use to absorb forces: springs, elastomers, and compressed air.
Spring damping systems are good for off-road as they offer the most amount of bounce when absorbing impact, but they tend to bob more on flatter surfaces.
Elastomers are better for the high-frequency vibrations you’ll experience when riding over bumpy surfaces at speed, such as gravel riding, and they feel more “natural” with less bob.
Elastomer systems can, however, freeze up in the cold, so consider this if you like to ride in cold weather.
Air damping systems are mostly used in telescopic seatposts, whilst an advantage is that they can be tuned more precisely, as we said telescopic systems generally aren’t considered to be as effective.
The Pros Of A Suspension Seatpost
The most obvious positive of a suspension seatpost is that they do subtly increase comfort, (when used correctly!)
By absorbing forces transferred into the body through the saddle the suspension seatpost counteracts exhaustion and soreness, allowing you to ride for longer and recover quicker.
We know from studies that managing vibrational forces is vital for good riding technique, personally, I’m open to accepting a little mechanical assistance.
Just know that the amount of absorption is fairly minimal versus actual bike suspension, seatpost suspensions can make for a slightly smoother cruise but don’t rely on them to absorb large bumps and bounces.
Suspension seatpost critics will point out that absorbing forces yourself is part of good riding technique.
It’s true that benefits will be felt most by beginners and heavier riders who might still be developing their strength and technique.
- Check out our guide to standing out of the saddle here for effective shock absorption.
Slipping off the saddle to absorb impact through the legs isn’t always an option, however, and a suspension seatpost can be good for the stoker on a tandem bike, who can’t stand or see and anticipate upcoming bumps as well.
Suspension seatposts are also much lighter and cheaper than a full suspension bike and could be mounted to a hardtail for a little bounce in the back.
In summary, seatpost suspension can offer a modest benefit, probably best for smoothing out casual rides, and shouldn’t be relied upon for more than that.
The Cons Of A Suspension Seatpost
The benefits of suspension seatposts are counterbalanced by some drawbacks which you need to understand should you choose to ride them.
In short, they’re essentially stiff shock absorbers; no replacement for proper suspension. Furthermore, their travel can diminish your peddling power.
Let’s explain:
A suspension bike, or wide, soft tires, will absorb all of the forces a seatpost suspension is designed for, so they’re redundant if you have rear suspension, or tires wider than 4 inches.
Next, let’s talk about whether a saddle that moves is something you’d want.
To ride correctly your saddle should be set to the correct height, i.e. the height which allows you to pedal correctly with proper leg extension, without causing injury.
Bike seat suspension negates this, meaning you’re not consistently pedaling from the correct saddle position, and unlike the dropper post, you can’t correct this as you ride.
Improper saddle height will make your peddling less efficient, the seatpost’s travel will absorb some of your pedaling energy, and a variable height caused by the bob will interrupt your cadence, frustrating your speed and power.
In my experience, these little annoyances can add up quickly, and it’s not something I like to have to think about whilst I ride.
Another important point is wear and tear on suspension seatposts at lower price points can cause them to move side to side during use which is especially bad for your hips and back, so it’s worth splashing out a little when purchasing.
These inconsistencies will also interfere with proper biomechanics which hold you on the bike and so this can make you more injury prone. These risks should be taken seriously.
Weight is another consideration, less grave than but still worth thinking about. Suspension seatposts can weigh anywhere from 100-500 grams, so make sure you really need it before taking on the weight penalty.
They can also creak during use, so if a perfectly maintained, silent setup is important to you, I’d personally find a creaky suspension seatpost distastefully noisy, but I acknowledge that this could be considered pedantic.
In summary, serious riders might look to their tires or frames for the suspension benefits, instead of suspension seatposts which will impede proper peddling, as well as add some weight and noise to your bike.
When optimizing your setup simpler can often be better, so consider if the suspension seatpost will give you what you’re looking for, or represents yet another part to maintain.
Should I buy A Suspension Seatpost?
Whether a suspension seatpost is right for you is entirely a matter of personal needs and preference.
Whilst it certainly won’t give you a comparable amount of suspension to proper suspension systems, they can add a welcome little extra comfort to your rides.
With all the information we’ve laid out here about the different styles, the pros, the cons, and a few recommendations, you’re ready to make an informed decision about where you stand in the debate.
Interesting …thought I’d mention the seating mods added to my Specialized Sirrus 6.0 which seems compatible with the standard non hydraulic ‘Future-Shock’.
First I added a Specialized MY17 Roubiax CG-R seat posted and topped it with an SQLab 610 Active.
Both saddle and bars. Seem si.ilaly damped and take the edge off sharp irregularities. Most of my riding is street and trails and my 80 yr old frame appreciates the reduced harsh inputs.
Nice article, thks, Retrogreg