Post contributed by Karleen Scase

As triathletes we always wonder about our race times and if there are ways to make us faster. If we hear “free speed” it definitely peaks our interest.  Being in an aero position while biking has large savings in both watts and increasing speed. STAC virtual wind tunnel can help find the speed.

Going to a wind tunnel isn’t readily available to most of us as athletes however a new scan is in place to gain this knowledge. STAC Virtual Wind Tunnel out of Toronto Ontario, and now calls Alberta home as part of 4iiii, has developed a program to analyze our position with a scanner so we can find our most aero position in a matter of minutes.

After the scan is done you are provided analysis-based feedback and recommendations to your most aero positions. They consider helmet, head position and nutrition and hydration location. By manipulating a 3D model of you on your bike, STAC can run comparisons of a number of configurations and positions, providing alternative solutions for your set up.

I recently had my scan done and here are some of the 3D images from it.


After reviewing my results I can see where watts can be saved and turned into speed.

By adjusting a couple of centimetres my position can add a few kilometres per hour with the same power. Not a huge difference you might think but over 180km it adds up.

Then we notice the helmet. Easy pickings. But most of use look at an aero helmet and think the fish bowl on our heads is just for the pros. But look at the blue turbulence below. I don’t even need to go to a full aero helmet. Just something a little more rounded would help.

Anyone notice something strange ? My shirt !! I never really thought about it. But a poor fitting jersey saps watts!  Now most of you think I am stretching here. But first it is enough that is shows on a scan but also keep in mind water is 784 times more dense than air. What drag is that adding in the water? Or even pooling it inside my wetsuit. Making sure we find proper fits is not only important for drag but also for comfort. Hard to hold an aero position if something doesn’t feel right.

That nice low pressure zone behind me is a perfect place to put some bottles. But this does raise the question about reaching back for water.

We spend a lot of time and money on aero bikes. Once we get them we assume we are faster. Along with a bike fit we have to ask is this the most aero position I can be in ? What about how I setup my cockpit?  Did I help or just add drag? Maybe skip the electric shifters and invest in an aero helmet. Is the sub second shift going to help over distance or saving watts from drag?

Coach Karleen