Anyone tested an aero seatpost to see if it makes a difference?

Triathlon Forum
1

I’m not going to be buying any new bikes soon, but I’m trying to optmize what I have and that includes a big, long round seatpost. I have about 16cm of post sticking out of my frame. Anyone done any PM field tests to see if the aero post is real or hype?
Chad

2

As I recall, John Cobb tested some in a wind tunnel and round posts had less drag. He theorized that it has to do with the turbulent air from the rider.

3

in most races I do my race number ends up wrapped around my seat tube in airfoil shape anyway. were it round, it wouldn’t matter, as I would still have my airfoil number fairing =)

I’m not going to be buying any new bikes soon, but I’m trying to optmize what I have and that includes a big, long round seatpost. I have about 16cm of post sticking out of my frame. Anyone done any PM field tests to see if the aero post is real or hype?
Chad

4

John Cobb tested them several years ago. His conclusion is that they don’t work if coming out of a round seat tube like the set up on my early model Giant TCR, but do work if they are similiar in shape to the seat tubes as with most aero frames.

5

You are not going to see any noticeable gains from an aftermarket aero seatpost. Most of the time the only difference noticed is an increase in ride harshness.

6

There was also some testing done which showed that when you have an aero post on a beam bike, that it improved the aerodynamics. So the answer to the question originally asked IMHO would be ‘it depends’. Like many of the multivariable issues with aerodynamics, there can be many people who are both right and wrong at the same time, and can show data to support their claims about being right…the devil is in the details.

stephen j

7

This is all from memory of what I read several years ago - so I might be remembering it wrong and/or it may no longer be state of the art knowledge.

Thin bladed seatposts did worse than round or thick aero posts when tested with riders.

I think thicker aero posts may have done better than round seatposts.

I bet the results hinge on how thick one’s thighs are and how much air is diverted or guided around the body up front (hands, arms, shoulders, chin, etc.), how high the seatpost or seamast extends above the top tube…

My personal wild guess is that what you do in the very front and the very rear are more important than what goes on in the middle.

David K

David K