Sometimes cycling is a real pain in the ass, literally. Especially for those of us who enjoy the path less travelled.
You’re probably thinking that you need a steel frame to smoothen out those uneven roads you want to travel, because steel frames are comfortable, right?
Frame materials and their design are actually relatively minor in the comfort equation. Road vibrations and hits are mostly absorbed through your tyres, seatpost and saddle. We’re talking millimetres to centimetres of shock dissipation for each of those components, far more than a frame alone can possibly offer your body.
Seatpost Choice Is Critical For Comfort
Seatposts are without doubt, the most overlooked component on a bicycle. I don’t know anybody who has ever picked a seatpost because of its riding qualities; instead people often look at how cheap, lightweight, reliable or how well it matches their bike. But if you’re selecting a component for its comfort, the humble seatpost should be the first place you look. A stiff seatpost tends to negate ALL benefits of a steel/titanium frame or slightly wider tyres!
Seatposts vary greatly with how well they handle both vibrations from the road, and bigger hits. Road cyclists have the most to gain from a well-designed seatpost given the reduced damping of their narrow tyres and harder saddles, but really, every cyclist can achieve a substantial comfort gain from a seatpost swap out.
Velo Magazine did some seatpost testing back in 2012, data which I will draw upon when making any conclusions in this piece. Click HERE if you’d like to read about their testing protocol.
The Different Types of Seatpost
Carbon, Aluminium, Titanium Seatposts
Seatposts can be manufactured with different materials. Most seatposts are made out of aluminium as they are cheap to manufacture, are lightweight and are reliable. Carbon seatposts are more expensive, but are the lightest in weight and offer an exceptional ride quality. Titanium seatposts are generally only used in conjunction with titanium frames for aesthetic purposes.
There are a handful of suspension seatpost manufacturers around the world, perhaps the most common is the Cane Creek Thudbuster. The advantage of a suspension seatpost is that it will take the jarring out of big hits, far more so than any rigid seatpost. The main disadvantage is the increase in weight.
Specialized insert an elastomer into their two comfort seatposts to achieve their desired ride characteristics. Using elastomers and carbon is a lightweight and reliable way to make an effective seatpost.
Straight and Setback Seatposts
Seatposts are available in different offsets. A setback seatpost puts you further behind your crankset and a straight seatpost moves you closer. The amount of offset on your seatpost is best determined through a bicycle ‘fit’ at a specialist shop. They will measure the relationship between your knee and pedal axle to optimise your cycling efficiency. You can read more on bike geometry and fitting HERE.
Damping is the speed at which seatposts flex. It’s the most important seatpost characteristic for cyclists riding on roads, which realistically is all of us. Seatposts with high-damping qualities insulate riders from the harshness of any road by reducing the vibrations coming up through the bike. A high-damping seatpost can be TWICE as good at absorbing vibrations than one that performs poorly!
Velo Magazine’s Damping Test Results
Straight seatposts of any material (carbon, titanium, aluminium) are the worst at damping shock. The best are often setback and made using carbon fibre. Almost all of the carbon seatposts in the Velo test outshone their aluminium and titanium counterparts, reaffirming the brilliant damping qualities of carbon as a construction material.
For those of us spending time exclusively on rough tracks and trails, damping bares little relevance. Enter seatpost flex…
Flex is the total movement that a seatpost will move after a hit. Seatpost flex protects a rider from potentially damaging jolts like unexpected pot holes or corrugations. A vertical and horizontal measurement can be made, ranging between 3-6mm of movement in each direction. When comparing rigid seatposts, some offer over almost 50% more flex than others (eg. the Thomson Setback flexes half as much as a Ritchey Carbon Setback). On a rough road or trail, that will make a lot of difference!
The best seatpost for rough roads, which is in another league altogether, is the suspended Cane Creek Thudbuster. It offers 3-4x MORE flex than the best rigid seatpost. The Thudbuster has been tested to move around 14mm vertically and 20mm horizontally. You can read my review of it HERE.
Velo Magazine’s Deflection Test Results
In general, carbon seatposts deflect more than similar aluminium ones, which is good for the bigger hits. Setback seatposts tended to flex more than their straight counterparts too. That makes a setback carbon seatpost the best all-round option for off-road comfort.
Horses for Courses
There is no seatpost that is the best for every road. Instead, you will have to compromise in some way. Do you need lots of flex in your seatpost, or are you just after the vibration damping? According to the Velo testing, you’d be best off with an FSA K-Force Light seatpost if you need damping, and a Ritchey WCS Carbon seatpost if you need the flex. The Cannondale and Specialized seatposts are great for all-round use.
The closest seatpost to comfort perfection would have to be the Cane Creek Thudbuster. The built-in elastomer allows both exceptional vibration damping on smooth roads and incomparable flex for the bigger hits on dirt roads. I review mine HERE.
The Most Comfortable Seatposts
Cane Creek Thudbuster ST – The best seatpost for bigger hits and one of the top for vibration damping. US$149.
Cannondale SAVE – A great all-round seatpost for both vibration and big hits. US$180.
Canyon VCLS 2.0 – This post receives excellent reviews for it’s unique design. US$299.
Ergon CF3 – Using Canyon’s technology, Ergon have produced a reputable comfort seatpost. US$299.
FSA K-Force Light – The best-tested seatpost for minimising vibrations. US$220.
Ritchey WCS Carbon – Great all-round seatposts for both vibration and big hits. US$209.
Specialized CG-R or S-Works SL Pave – According to Specialized the CG-R has the most vertical compliance of any non-suspended seatpost. The Pave tested very well for vibration damping in Velo’s testing. US$149 to US$199.
Syntace P6 Carbon Hi-Flex – This highly-reputable seatpost is light and is said to flex up to 20mm. That would rank it highly for both vibration and bigger hits. US$199.