Aerodynamics on a roadbike: how do different grip positions have an influence on your performance?
Integrated hydration systems, individual cockpits out of a 3D printer and aerodynamically hidden brakes – aerodynamic aspects are currently the driving factor in timetrial cycling and triathlon. There’s probably no pro out there who hasn’t been testing in a wind tunnel or velodrome.
A trend which more and more amateur and agegroup athletes have been picking up on. A fact which makes perfectly sense in the fight against the clock, since wind resistance in relation to speed increases to the second power. Therefore in triathlon or time trailing I can massively gain a time benefit by being aerodynamically optimized.
But are these findings transferable to a road race? What is the role of aerodynamics within the peloton? And how much energy or power can I actually save on a roadbike? By starting this new series we want to tackle the following questions:
Which influence do arm position, seating position and equipment have on your roadbike?
The likelihood to be able to stay inside a box during the entire stretch of a race is pretty low. In most occasions the dynamics of a race will require that we have to close gaps or conduct the working part in the lead and of course there are always the hotshots who calculate the chance by breaking away.
As a start: Aerodynamic optimization on a roadbike starts with the position. So before your first step should be to go to a bikefitter before you start investing in expensive equipment and gadgets. The basic for conducting aerodynamic tests should be the balance between most comfortable position and most power generating position in regards to your racing characteristics (duration, type etc.).
Now we can start with working on optimization. In road cycling there are more limitations compared to triathlon, since the UCI Regulations are strict in regards to what you are allowed to do and what you can add or change. Your bike geometry and handlebar type is basically set and does not give any room for creativity. However, there are still many things you can do to save some watts, and still be legal.
In this first test I took a look at the effects different handlebar positions have. The most amateur cyclists ride with their hands on the top of the bars, the breaks or the bottoms part. That’s why in this test I took a look at these three positions and to maintain a comparable result I maintained my arms completely stretch in all three runs.
At a first glance my results should not look to surprising: I achieved the best aerodynamic results while cycling on the lower ends of the bars and my worst with my hands on the top. These could mainly be a result of the hip angle since the seating position is more upright compared to the bottom ends or the brakes. The effective frontal area standing in the wind is significantly larger.
But what surprised me was the large amount of saving potential there is by being more dynamic with the hands on the bottom ends. The difference in my test between the top end break ends was relatively small while keeping my arms stretched. My CdA with the hands on the top was at 0.424 sqm and was reduced by 0.01 to 0.414 sqm with the hands on the breaks.
Looking at this from a time point of view by using the aeroCAST tool however gives a more transparent light. I used the 180km Challenge course in Roth with an average power at 200w as my calculation baseline. By riding this completely in Position 1 it would result in 5:45:09 hrs. By changing to the Breaks I would improve by three minutes.
But changing to the bottom ends has a large impact. Just by changing to this position my CdA dropped to 0.366 sqm. Taking this on the Roth course would result in a time advantage of 14:55 min, meaning that with 200w I would now arrive after 5:30;31 hrs. The bottom ends make a huge difference.
In the next post we will show you more optimization possibilities by doing some changes to your arms position.
Follow the link to my testsuite!