1. The Helmet
An aero helmet is not just about finding the most aerodynamic helmet, it is about finding the helmet that matches your body shape and riding style best. For me, I move my head up and down often to relieve stress on my neck from the low riding position I utilize. Because of this, I wanted a helmet that would not penalize me when my head was down, but one that also still had a tail on it that would add some weight and pressure behind the head to also help alleviate weight on the neck with the head facing forward. The John Cobb designed Rudy Project Wingspan helmet was designed in the wind tunnel to fit well with many different back structures and the head facing up or down.
The only thing it is missing is a hole on top to more easily dump water in without having to tilt the head in a non-aerodynamic position.
2. The Front Aero Bottle.
For awhile I played around with having an actual bottle here, but found for anything hot or longer than half-Ironman, I just would not drink enough. For me, the effort to get the bottle out of the cage not only kept me from drinking as much as I would like to, it also moved me out of an aero position while I had to tilt my head up to drink. This also prevented the constant sipping technique that is much more efficient for hydration that can be employed with a straw sticking directly in your face. When I went back to the simple, but proven, Profile Design aerodrink, racing in the heat became easy again. However, I might consider upgrading to something that might be a bit more aerodynamic, like this http://www.profile-design.com/profile-design/products/hydration---nutrition/all-hydration/aero-hc-system.html in the future.
3. Front Brake
While upgrading to the TriRig Omega front brake was probably just as much for looks as for time savings, an estimated 2W (from this article here http://www.tririg.com/articles.php?id=2012_07_Omega_Wind_Tunnel_White_Paper) is still 2W. And at my lower level of power production and speeds, quite important.
4. Cable Routing
One thing the Omega front brake allowed, was also a much more efficient cable route that sends the cable right in front of the bike and not out to one side. The other cables have similarly been routed behind the cockpit structure and into the bike frame, thoroughly out of the way.
5. Flat Repair Kit
I wanted a flat repair kit that could tuck up underneath the seat as much as possible and be small and compact. An Ironman race is too long to go without one.
6. Nutrition Storage
For nutrition, I wanted something easy to access, aerodynamic, with strong sidewalls that wouldn't let it fall to one side where my knees would constantly brush it and become irritated, while also holding 4-6 emergency gels (for when I miss grabs at the aid stations) and a cut-up Larabar to keep my stomach from growling. The DarkSpeedWorks Speedpack 483 met these needs perfectly.
While I had to give up the solid TT chainrings to go with the Quarq Sram Red powermeter, the tradeoff was well worth it. At Ironman Texas the course profile is rolling with a tailwind out and a headwind back in. I chose to hold a lower power on the way out with the wind as well and lots of people to pass, and then increased power by about 8% on the way back into a headwind with no one in sight except for a few athletes that had blown up in the heat and were just struggling to make it back in. With no one around to pace off of for a good 40 miles into a headwind on the back stretch, the only way I was able to keep the speed up was to simply keep hitting those numbers on the screen. The powermeter also allowed me to keep from riding over threshold on the few steep hills encountered, as well as to keep the power up a little on downhills with tailwind. All of which help to make for a more efficient ride where a strong run is possible.
8. The Components
Now why would these matter? Well an old chain and worn out components can cost several watts. Leading up to the race, the newest cassette was chosen, the rear derailleur cleaned, and a new chain installed. For the next big race though, I will have my chain stripped and re-lubed with this process here
9. The Saddle
While not directly related to aerodynamics, the John Cobb V-Flow Plus saddle aids in allowing me to comfortably ride in a very forward position (sometimes referred to "on the rivet") where I am powerful and aerodynamic.
10. The Cockpit
While nothing too special from the stock felt cockpit has been done here, it has been lowered with an effectively shorter, horizontal stem to get as close to the top tube as possible for slightly better frame aerodynamics. The most important part here is that I am comfortable and low.
11. The Wheel/Tire Combo
Aside from body position, the wheel/tire combo is the most important piece of aerodynamics. Flo Wheels aren't the lightest, but they are some of the very best aerodynamically, which is what matters most (see this article for weight vs aero http://flocycling.blogspot.com/2014/03/flo-cycling-aero-vs-weight-follow-up.html). Next was matching the correct tire to the wheel for the fastest wheel/tire combination. For this, a 23c Continental GP4000S was chosen for the front tire because of test results from this article http://flocycling.blogspot.com/2013/04/flo-cycling-flo-30-wind-tunnel-results.html that show a much lower drag over the current Vittoria Evo Corsa that was being used. After that, rolling resistance is of primary concern. Rolling resistance test results can be found here https://docs.google.com/file/d/0B-JYBb4ZA401SjJGYmRONTVVeGs/edit with information about why it is so important here http://bikeblather.blogspot.com/2013/04/why-tire-crr-matters.html. With that information on hand, Vittoria latex tubes were ordered and the Vittoria Evo Corsa was left on the rear tire for the lower rolling resistance offered by each. Eventually, the Evo Corsa will be replaced by another GP4000S or Michelin ProRace 4 for the aerodynamics these tires offer on the Flo Wheelsets, but with the leading edge of the rear tire being mostly blocked by the frame of the bike, it is not a current concern. Whatever wheels you use, it is very important that the front tire, at least, matches well aerodynamically with the wheel. Lastly, a wheelbuilder disc cover was also added to make the rear Flo 90 into a similar profile of the Flo Disc, which can lead to a large reduction in drag at higher yaw angles (see above link for Flo wind tunnel results).
12. The Bike
What I wanted here was very simple. A frame that had some aerodynamic testing, simply to ensure it wasn't a relative brick in the end. But, since frame aerodynamics are such a small part of the equation, the most important thing I wanted from the bike was the right stack and reach coordinates to provide the ultra low and comfortable fit I was looking for.
13. The Fit
The fit was designed to be a low, compact position that still allowed good leg turnover without challenging my hip flexibility and kept my chest open to facilitate breathing. I was able to do both of these with a retul fit that first put my hands together at the front, but angled my elbows to align with my hips to open up my chest without losing aerodynamics; and second, utilizing shorter 170mm crank arms to keep my hip flexors and calves from working too hard at the top of each pedal stroke due to a tighter hip angle than optimal with the stock length 175mm crank arms. The cockpit was also designed to be shortened 20mm with a 90mm stem in order to move center of gravity rearwards slightly for better handling characteristics and control.
Front Profile: Here you can see the cables are hidden, the front brake is seemless and the elbows are in line with the hips with the hands generally together.
Side Profile: Here you can see the flat back, the face forward profile of the helmet, the covered Speedpak, the tucked in flat repair kit, and the open hip angle allowing comfortable pedaling.
Head Down Profile: A common position during Ironman to relieve stress on my neck, and why I wanted the short, slanted tail of the Cobb Designed helmet to get optimal aerodynamics here.