My goal in designing this shoe is not simply to make an aerodynamic shoe. It's to make the best triathlon shoe made, and to include in the design process a real analytical effort to reduce aerodynamic drag, without compromising fit or function. I hope that even if one does not believe the aero data, or tests the shoe themselves and gets different results, they still decide that this is the shoe for them.
I can truly say that this is the most comfortable cycling shoe I have ever worn. I can also say the materials and craftsmanship of the upper are top notch, as one would expect from an Italian factory that's been making shoes for 46 years.
Like aero helmets, the aerodynamics of shoes is individual to the rider and there are lots of complicated non-intuitive things going on. Not everyone will experience the same thing. The results below are what we got for me mounted on a 2020 Felt IA Advanced. All that being said, given that this shoe is the only one in which real analytical tools were used during the design process to reduce aerodynamic drag, I think most riders have a good chance of seeing an improvement if they use this shoe.
Testing was done at 30 mph. A little more geeky discussion about that a little lower down. All shoes were size 44, but that does not mean they are actually the same size. The S-Works shoe was the smallest by quite a bit, giving it the lowest frontal area. It's possible that someone who prefers a 44 in the Bontrager might actually prefer a 44.5 in the S-Works - but maybe not. I was able to wear all shoes comfortably. Every effort was made to keep q-factor identical between shoes.
(photo: Kenny Withrow)
(photo: Kenny Withrow)
The validity of testing at 30mph has been discussed a lot on ST and people question why tests are not done at a speed more representative of an AG athlete. The reason we did not do this is because at 30mph, we can get the CdA and use that to look at the differences in drag at any speed we want much more accurately than if we tested at 20mph. The reason for this is because the signal to noise ratio gets too high as the test speed gets slower and it could easily become impossible to detect differences in positions or equipment. Using the CdA of 30 mph at slower speeds is valid because CdA of a cyclist has low sensitivity to Reynolds number in these ranges of air velocity - in simple terms the behavior of the flow around the cyclist is not going to be sufficiently different at 20mph vs. 30mph, so the analysis is scalable in that range.
An example of using this scalability:
If a cyclist can complete a 40kTT in 1 hour, using the CdA's of the shoes and applying a typical distribution of yaw angles, we can calculate that based on this data, using the VeloVetta prototype that cyclist would complete the 40k 32 seconds faster.
If a triathlete can complete the bike leg of an Ironman in the TR9 in 5 hours, this data suggests using the VeloVetta prototype they could complete it 4 minutes and 20 seconds faster.
The distribution of yaw angles used for these analyses are essentially the one published by Flo (http://flocycling.blogspot.com/...n-series-step-2.html) massaged a bit to fit the data points we took.
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Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook
I can truly say that this is the most comfortable cycling shoe I have ever worn. I can also say the materials and craftsmanship of the upper are top notch, as one would expect from an Italian factory that's been making shoes for 46 years.
Like aero helmets, the aerodynamics of shoes is individual to the rider and there are lots of complicated non-intuitive things going on. Not everyone will experience the same thing. The results below are what we got for me mounted on a 2020 Felt IA Advanced. All that being said, given that this shoe is the only one in which real analytical tools were used during the design process to reduce aerodynamic drag, I think most riders have a good chance of seeing an improvement if they use this shoe.
Testing was done at 30 mph. A little more geeky discussion about that a little lower down. All shoes were size 44, but that does not mean they are actually the same size. The S-Works shoe was the smallest by quite a bit, giving it the lowest frontal area. It's possible that someone who prefers a 44 in the Bontrager might actually prefer a 44.5 in the S-Works - but maybe not. I was able to wear all shoes comfortably. Every effort was made to keep q-factor identical between shoes.
(photo: Kenny Withrow)
(photo: Kenny Withrow)
The validity of testing at 30mph has been discussed a lot on ST and people question why tests are not done at a speed more representative of an AG athlete. The reason we did not do this is because at 30mph, we can get the CdA and use that to look at the differences in drag at any speed we want much more accurately than if we tested at 20mph. The reason for this is because the signal to noise ratio gets too high as the test speed gets slower and it could easily become impossible to detect differences in positions or equipment. Using the CdA of 30 mph at slower speeds is valid because CdA of a cyclist has low sensitivity to Reynolds number in these ranges of air velocity - in simple terms the behavior of the flow around the cyclist is not going to be sufficiently different at 20mph vs. 30mph, so the analysis is scalable in that range.
An example of using this scalability:
If a cyclist can complete a 40kTT in 1 hour, using the CdA's of the shoes and applying a typical distribution of yaw angles, we can calculate that based on this data, using the VeloVetta prototype that cyclist would complete the 40k 32 seconds faster.
If a triathlete can complete the bike leg of an Ironman in the TR9 in 5 hours, this data suggests using the VeloVetta prototype they could complete it 4 minutes and 20 seconds faster.
The distribution of yaw angles used for these analyses are essentially the one published by Flo (http://flocycling.blogspot.com/...n-series-step-2.html) massaged a bit to fit the data points we took.
-------------
Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook