Road Bike Seatposts
The Seatpost is a simple tube that connects your saddle to your Road Bike. Seatposts are made from aluminium or carbon as it need to be strong to support the weight of the rider. It is a very important component: a good seatpost will reduce vibration and increase your comfort.
Which Road Bike Seatpost is right for you
Materials
-Alloy: aluminium seatposts are very common and popular, thanks to their low price. They are commonly found on low to mid range Road Bikes.
-Carbon: carbon seatposts are very strong and light. They are also more comfortable due to its vibration absorbing characteristics. Carbon fibre seatposts are much more expensive than alloy ones but they have a very long lifespan.
Sizing
Diameters vary in increments of 0.2mm. It is very important to choose the correct diameter: a seatpost too big or too small can damage your frame.
Most modern Road Bikes accept a 27.2mm seatpost. An oversized seatpost add stiffness, strength and resistance but a narrower seatpost will be more comfortable.
If you want to use a narrower seatpost on your Road bike, you can use a shim to enable the seatpost to fit into your Road bike frame.
Length
Lengths range from 75mm to 430mm. It is essential to have a minimum amount of post remaining inside the frame to avoid the risk of damage. Always make sure to have at least 10cm of post inside the frame.
In many cases, Road bike seatposts will have a minimum insertion line.
Choose your seatpost length to fit your frame size and geometry and your own dimensions.
Layback
A seatpost shaft can be Inline or Layback.
-Inline seatpost: the saddle clamp is in line with the shaft of the post.
-layback seatpost: the saddle clamp is slightly farther back relative to an inline post.
Clamp
Make sure the clamps will fit the rails of your saddle. Most of the posts feature a clamp designed to fit a twin rails saddle.
Some eavy duty saddles use 8mm rails.
Aero Posts
While most seatposts are circular, some seatposts have an aerodynamic shape.
A full aero seatposts will require a frame with a matching seat tube.
Sometimes, the bottom half is circular with only the top part shaped to a bladed aero profile. In this case, you just need to choose the correct diameter for your frame standard.