Cycling Aerodynamics – How Much Can It Really Help?
There are two ways to get faster on a bike; increase power or increase aerodynamic efficiency.
For most of us it is very difficult to make 5% power gains, it takes lots of work and dedication; however, many of us are able make immediate 10-20% aerodynamic gains. Aerodynamics is one of the simplest and fastest ways to gain free speed.
Biggest Drags in Cycling Aerodynamics
Aerodynamic drag accounts for approximately 80-90% of the resistance felt while pedaling. Of that 80-90%, 70-75% of that drag comes from your body and the remainder from your bike. So it stands to reason that the biggest gain can be from changes in your body. I am not talking about weight loss, (although that would help) I am talking about body position.
Getting into the “aero” position as opposed to being on the hoods can save 3 – 6 minutes in a 40 km time trial. That is a ridiculous difference. Lets look at some other factors and costs.
Comparing Different Situations Related to Cycling Aerodynamics
Approximate savings over a 40km time trial:
- Aero Helmet vs non aero helmet – 1 to 1.5 minutes – $150 +
- Aero bars vs upright position – 3 to 6 minutes – $50 ++
- Shoe covers vs non shoe covers – 30 to 60 seconds – $50 +
- Rear disc wheel + front deep dish vs spoke wheels – 1 – 2 minutes – $1000+++
- Skin suit vs Normal Jersey – 1 – 2 minutes – $250 +
As you can see some aero purchases can save you a significant amount of time, but the largest aerodynamic gains are from your body position. Don’t go out and buy the most expensive gear before you dial in your body position.
Try to keep things in perspective, a $200 helmet can save you almost as much time as $3000 wheel set.
Above it basically says drop your body to make your torso as flat as possible. The flip side is knowing how far is too far. Flexibility plays a huge role in being able to get in the most aerodynamic position. As luck would have it, flexibility is my weakest area, so I am like a sail out there.
My hips, glutes and hamstrings are my limiters when it comes to a more aero position. I can’t even come close to touching my toes… my focus over the winter… foam roller and stretching.
There is a sweet spot in dropping low enough to be aero and being upright enough to be comfortable and produce power.
Roll Down a Hill
Test how slippery you have become with the small tweaks you have made.
Before you make any changes find a hill that resembles a ski jump and roll down it from a complete stand still and see how far up the other side of the hill you make it. Mark the spot where you have come to a stop and repeat this a few times.
After you make a change redo the test… did you go further up the hill