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| Testing @ A2 Windtunnel |
in Mooresville, NC. Although costly, I knew this was something I had to do to continue to improve as a professional triathlete. Unlike physical training, which focuses on building a bigger engine to go faster, this trip focused on making me more efficient by helping my cut thru the air like a knife.
While I had been familiar with the wind tunnel based on the reports of others, actually going to a wind tunnel gave me an entirely different perspective. This perspective will not only make future trips more efficient in my own planning, goals, and expectations, but it also gives me better insight to ask better questions of others. While aerodynamics seems like something of a dark art, it represents an opportunity for improvement for those that are willing to spend the time, money, and effort.
Given the complicated nature of aerodynamics I will be displaying numbers in two different formats. The geeks prefer to see results in CdA. I will also present the numbers in a simple 'watts' format. In this format, I will show the number of watts needed to go 26.0 mph. 26.0 mph is my typical Ironman 70.3 speed which equates to a 2:09:13 bike split.
For those people who are not experts at aerodynamics, please note the watts showed only include aerodynamic drag, it does not take into account the energy it takes to overcome rolling resistance nor does it take into account drivetrain losses. In addition, I tested at different wind angles referred as yaw. I don't want to get overly complex and discuss yaw. The important thing to know is that the real-world wind angles a rider experiences while cycling vary moment to moment. I chose to test at 0° and 10° degrees. This represents the majority of wind angles that I am going to experience in my races.
1. Baseline - the first thing I did was establish my baseline numbers. This represent the starting point which I hope to improve thru further refinement.
0° = .246 .CdA
0° = 238.1 Watts (Watts to go 26.0 mph)
10° = .215 .CdA
10° = 207.8 Watts
2. Position Changes - I then moved to making various position changes. I narrowed elbows, moved the saddle back and forth, the aero bar up and down. The data and pictures below represent the final position changes that I accepted. The changes were raising my front end up 1cm and along with narrowing my elbow pads by 2cm (1 cm each side) .
0° = .240 .CdA
0° = 231.8 Watts
10° = .211 .CdA
10° = 203.6 Watts
3. Helmet Changes - I then moved to testing helmets. I had already been using a helmet that had proven to be fast on a high number of riders - that helmet was the LG P9 Helmet. I also tested a Kask Bambino, Catlike, Specialized S-Works TT, POC Cerebel, and Wasp Air. Often times some big changes can be found with helmets but for me the LG P9 was already the fastest. Pictures below show the second fastest helmet choice for me - the Kask Bambino.
Please note that I went to the tunnel before the Giro Aerohead MIPS came out. I now use the Aerohead MIPS and I did a short write-up on why that is here.
0° = .240 .CdA
0° = 231.8 Watts
10° = .211 .CdA
10° = 203.6 Watts
3. Race Kit Changes - I then moved to testing clothing. I started in a 2XU one-piece sleeveless kit that I raced in for years and was a size small. I also tested the 2XU sleeved kit that I had that was size small, a Cuore small sleeved suit, and a Cuore extra small sleeve suited. The Cuore extra small kit tested fastest and the results and pictures below reflect that.
0° = .235 .CdA
0° = 226.9 Watts
10° = .207 .CdA
10° = 200.4 Watts
4. Compression Sleeves - Given my large calves, I thought that adding some compression sleeves might help reduce drag. In the end, I had some 2XU MCS Compression Leg Sleeves (Amazon) (eBay) (Trisports). They were faster and the results and pictures reflect the change.
0° = .232 .CdA
0° = 224.3 Watts
10° = .208 .CdA
10° = 200.5 Watts
5. Shoe Change - One last change was shoes. I moved from some Pearl Izumi Octanes to Giro Empire SLX. The end results was the Giro Empire SLX were faster. The below reflects the final accepted change. For those interested, I did a full write-up of my Giro Empire SLX shoes with elastic laces.
0° = .229 .CdA
0° = 221.5 Watts
10° = .200 .CdA
10° = 192.8 Watts
Final Analysis - Looking at where I started and where I finished you can see that I made some considerable improvements in reducing aerodynamic drag despite already having the optimal helmet.
0° .246 => .229 .CdA
0° 238.1 => 221.5 Watts (16.6 watts decrease)
10° .211 => .200 .CdA
10° 203.6 => 192.8 Watts (10.8 watts decrease)
What this means in the real world is that it would take less watts to go 26.0 mph. Or I could keep putting out the same watts and go even faster. Overall I was satisfied with my experience and certainly recommend the process for anyone that really cares about their race time.
Feel free to ask any questions you might have in the comments section below. Also, I will be writing a lot of good stuff in the next year. If you haven't followed me please do so. Links on the right side of the page include: Facebook, Twitter, Instagram, Youtube, RSS, and Google+. You can also follow the blog by email as well.
My Links:
- Spreadsheet with all data
- Post: Fastest Ironman Bike Shoes - Aerodynamics + Weight - Cycling
- Post: Giro Aerohead MIPS Triathlon Aero Helmet Review
Product Links
- 2XU Elite MCS Compression Sleeves (Amazon) (eBay) (Trisports)
- Giro Empire SLX Review (Amazon) (eBay)
Lastly if you are triathlete or endurance athlete, I am setting up a FREE Q&A group on Facebook. It will always be FREE. As a long-time age-grouper I spent way too long determining what information I could trust and what I couldn't. As a TRUE student of the sport I have learned a lot, remain open-minded, and realize that so many people disseminate information blindly and then myths become lore. Hoping to shed some light and simplify things for people.
