Cycling, Gear & Technology, Podcast

The Hour record and aerodynamics with Dan Bigham | EP#368

 December 12, 2022

By  Bernardo Gonçalves


Dan Bigham - That Triathlon Show

Dan Bigham is a performance engineer at INEOS Grenadiers, founder of Wattshop, and former World Hour Record holder (with 55.548 km). In this interview, we discuss the hour record, the Sub7 project that he was heavily involved in, and the latest and greatest in the world of aerodynamics.  

In this episode you'll learn about:

  • Dan's training, testing, and overall preparation leading into the Hour Record
  • Pacing strategies and dealing with the heat
  • Dan's estimated power and CdA for the Hour, and could he go even faster?
  • The Sub7/Sub8 project
  • Do's and don'ts (or what works and what doesn't) in aerodynamics based on Dan's current knowledge
  • Aero-impact of trisuits, calf guards, shoes, camelbacks, Anemoi Sailfish hydration system, and rolling resistance impact of tires
  • Listener questions on aerodynamics (shaved legs, craziest thing Dan has ever done in the name of aero, and more)

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Dan's background

03:17 -

  • I am the performance engineer at Ineos Grenadiers, founder of Wattshop and former hour record holder.
  • Alex Dowsett experienced the same as I did when Bradley beat his hour record a month later.
  • I held the hour record for longer than Liz Truss being a Prime Minister.
  • I took the hour record on the 19th of August 2022, where I did 55.548 km, and Filippo took it from me with 56.792 km.

The decision to take on the hour record

05:03 -

  • The decision to do came soon after taking the British hour record in 2021, where I did 54.723 km to take Bradley Wiggins' hour record.
  • It solidified that it was possible to beat the hour record, so we started the process of being in the whereabouts program and finding that extra distance.
  • It was a fun process. The key was joining Ineos and the support they gave me.
  • Filippo and I wanted to go for the hour record, so connecting everyone within Ineos Grenadiers became an excellent project.
  • Concerning finding the distance, it is what I do day in and day out, thinking of things like this.
  • In some respect, it is a formal process where you have brainstorming sessions and discussions, but most are about informal research (internet, books, speaking with people).
  • Then, we look at checking where my losses are and move those forward.
  • I am always thinking energy-wise: how can I reduce my drag, rolling resistance, and drivetrain drag...?
  • Joining Ineos opened many doors to the other side of the equation. (putting more energy in)
  • I train as best as possible but have experts in nutrition and physiology coming to help with ideas for increasing power output in extreme conditions.
  • We looked at thermal physiology because it is a critical determinant for the hour record.
  • My goal for the year was the hour record, so everything was tailored to that.
  • After the Sub-7/Sub-8, I went to Grenchen to do a full rehearsal.
  • Everything at that point was optimal. (pre-cooling strategies, nutrition, pacing strategies, equipment)
  • There I broke Victor's hour record in training by half a lap.
  • It cemented that we would do it but emphasised that preparation could be better.
  • Between June and August, we found 300 meters in many ways.
  • Looking back to my October record for this year, the 800 meters I found were in 50 % drag and 50 % energy.

The numbers from the hour attempt

09:46 -

  • I cannot give you the numbers because I do not have them.
  • I did not ride with a power meter in either of the attempts.
  • The power meter options increased my drag, and I would prefer to go further and achieve the goal without knowing how I did it.
  • All I can give you is the watts per CdA.
  • My power output did not improve significantly from October 2021 to August 2022.
  • We could create a lower drag scenario by putting temperature, high humidity, and the same power in a more extreme condition.
  • We trained to increase power output, but the preparation focused on tolerating the more extreme conditions.
  • It was around 350-355 W in power terms, which puts my CdA in the low 0.15s.
  • It was lower than that for the first 30-40 min, but CdA started to drift up in the last 5-15min of the attempt.
  • Our pacing strategy focused on delaying that dropoff and keeping core temperature and general fatigue as low as possible.
  • The end-of-the-hour record focuses on getting good lines and everything out of the tank without exploding or falling apart.
  • When you fall apart, your power decreases, and your position worsens. You may be 5-10 W down and have a 5-10 W aero penalty.
  • Your speed slows down, and your optimal cadence is not what it should be, quickly becoming grim.
  • You worked on pushing that breaking point as far as possible.

Temperature and humidity

12:45 -

  • Victor struggled because the velodrome where he did had drastic temperature variations.
  • He started early, and he saw a 3ºC temperature increase.
  • You cannot control the temperature in that velodrome.
  • Grenchen is well-isolated, and the issue is when it becomes too hot.
  • We were on the safer side compared to Bradly Wiggins.
  • They had a high-pressure wave in London and compensated by increasing temperature.
  • However, you see a drop in gross efficiency as your Core temperature increases, so there is a balance that we need to consider there.
  • We pushed the temperature as high as possible and did training to adapt to it.
  • On my hour attempt, we had a 27.3 ºC average and 53% humidity.
  • Last year, I had 25ºC and 40-45 % humidity.

Heat optimisation

14:44 -

  • From a training perspective, I was doing a considerable amount of pantsuits works.
  • It was an idea that came from Core. They developed cool models describing where all the cooling capacities come from and how you can influence those parameters and impact performance. (e.g. how much ice you eat and your performance increase)
  • You want to keep as cool as possible before the effort. You want a warm-up for the psychological side, but also muscle temperature needs to be slightly elevated, so we try to do it without raising the core temperature.
  • Moreover, having a negative split strategy means you do not need to worry about having an intense start because you will roll out and be 20-30 W below the threshold.
  • Even if it is at the "sweet spot area", it is manageable, and you can roll and build the effort.
  • Beyond that, we need more details, like putting the helmet in the freezer or using menthol. (it will not have a physiological effect, psychologically you will feel cooler)
  • The body responds to how it perceives it to be and not how it is. If you feel cooler, you will behave accordingly.


17:26 -

  • The negative split might be hard psychologically because you will have to ride harder at some point, but you can push into it and find that limit.
  • Instead of thinking of sustaining 55.5 km/h, you will go out easier and push until you find the limit yourself.
  • The time trialists that understand their bodies can find and sit on that limit.
  • Initially, your sensations do not align with your actual physiological state.
  • Therefore, you will be safe because you will not push more than you need to.
  • It will not impact your distance significantly. People say there is non-linearity with aerodynamic drag, so riding slower and faster will cost you more. However, the differences are minimal when you run the numbers.
  • For example, in my case, it cost me 12 meters. (0.2 W in terms of power production)
  • By doing that, I keep my body core temperature lower and improve my line and position.

Core temperature training

19:22 -

  • I used the core sensor even before I joined Ineos.
  • We first used this sensor in 2021 when we did some practice hour runs at Manchester velodrome.
  • We used it with other skin temperature sensors and the pill core sensor.
  • We realised its importance because my body core temperature was high at the beginning of the attempt, and when I hit 40 ºC, things started to go down pretty quickly.
  • I was on pace for 40min, and it went downhill after that.
  • Once you understand the sensations of what different Core temperatures feel like, you will control them better.
  • You only know your zones like a power meter once you get one.
  • I used it in preparation and during the record to understand what happened.

Reviewing Dan's attempt

21:21 -

  • Generally, it went as well as we can plan it.
  • Of course, there are minor details I could have done better. For example, my last five minutes were safe. I knew I had the record, so I did not ride as close to the black line as I did previously to avoid making mistakes.
  • It cost me a couple of meters per lap for 20 laps, but the preparation and the run-in were like a military operation.
  • Ben Williams is our integration performance leader that has a military background.
  • He is an organised, logical and objective person that puts plans in place that get executed cleanly.
  • It is a pleasant environment because I typically have to be that person and the athlete.
  • It meant that I did not have to worry about the food I take, my training schedule and my bike.
  • It is a relief as an athlete to go in and execute the process without worrying about minor details.
  • Therefore, we might have found 50 meters in a better run.

Hour-record training

23:29 -

  • There was not a typical week. My lifestyle does not allow me to do four consistent weeks doing the same thing with a bit of progression.
  • Most trainings was on my turbo. I use the Lemond revolution direct trainer because it matches the inertia of the track.
  • I did everything on the position in the TT extensions.
  • In most sessions, I was doing 30-60min of heat exposure, where I would put the pantsuit and get the core temperature up to 38.5 ºC.
  • I did a reasonable amount of sweet spot into threshold efforts. (e.g. 60min of 8.5min below threshold and 1.5min above while progressively increasing the intensity)
  • Much of this was in altitude. (I live in Andorra - 1500m)
  • It is enough to have an impact on performance.
  • When I was in Grenchen 8-9 days before the event, I did a lot of track training. (aero testing)
  • I had not tested the printed Bioracer suit, so we had to test it to check if it was fine and get all the data to tick all the firing points.
  • We made some more extended efforts to see if I could replicate the first 15-20 minutes. Therefore, I would go out below threshold for the first 15 minutes and accelerate slightly to have fun.
  • There were no super strict sessions where I would go out and do six hours daily.
  • Everything was regimental on the turbo.
  • I would do two specific weekly sessions, and they would have volume in them and heat.
  • I was doing around 16-20 hours per week (16-17h yearly average).
  • If I have the opportunity to do more time, I will do it, but on the whole, it is about being consistent weekly.
  • I also did a gym session once a week, and I am now looking to increase that a bit to do individual and team pursuits.

Non-structured training intensity

27:53 -

  • I would train in zone two in a five-zone system.
  • I am someone that pushes higher to tempo intensities.
  • I do 3-4 hours in the TT position on the turbo with a five-minute break to go to the toilet.
  • I live in a ski resort which is excellent for altitude, but I am not a fan of hills and do not like the waisted time of descending.
  • For each hour, I am making a 15-20min descent. So, 25 % of the time is wasted on a four-hour ride which is frustrating because I am time-constrained.
  • So, I do most training indoors, keeping it in a tight power band.
  • I am on a Lemond trainer, so I do not have Erg mode.
  • I have a Kicker and Neo 2T, but I do not use them as much because I prefer the feeling of the Lemond.
  • You can model it to match the inertia you would get on the velodrome or the road.
  • You cannot do that on the Tacx or the Kicker.
  • Lemond is not quiet.

Project sub-7 performance debrief

30:13 -

  • We did a five-kilometre circuit (a big velodrome).
  • We did a time trial with one-lap turns.
  • We had to know everyone's CdA to understand who should ride in the team and what would be possible.
  • We got power targets for each athlete (410-450 W at the front).
  • CdA ranged from 0.16 to 0.19, which makes power vary much.
  • On a flat surface, W/CdA is the essential parameter.
  • Some guys were doing shorter turns, and we broke it down to half or complete laps.
  • Dowsett and I did complete laps, but we varied depending on how we felt.
  • I blew my doors off with one hour to go.
  • I did good preparation in altitude, but I had to fly back during the week for my sister-in-law's wedding. So I flew back in the night before and did not go to bed until midnight.
  • It is not an ideal prep, but it was how it worked out. (late-night and early start)
  • Nevertheless, we paced it well.
  • We went out with a target of 55 km/h. When we first presented the numbers to the athletes, athletes were not sure we could do that.
  • We knew that the last hour would be more challenging.
  • The heat was a factor for many athletes.
  • It was 30 ºC with no shade and no rest either.
  • The fastest way was to have all ten athletes on the line and not give any rest.
  • We would sit at 240-260 W on the bike, and it would increase for the first three guys. Man three would be in the high 200s, man two was close to the threshold, and the front guy was riding close to VO2.
  • One lap was slightly over six minutes. We were getting splits through the radio because we were trying to get faster and faster.
  • Alex did the fastest lap with 2-3 laps to go. (58 km/h)
  • We did not have to do many spikes to get back in line.
  • We could do a few seconds in the 400s because we would change in the banking, and we would have the advantage of the height difference to help with the acceleration.
  • If you change on the straight, you would have to lose speed and regain speed.
  • The line was smooth. Of course, there were some moments where you had to respond, especially in the tailwind sections.
  • There were moments when we had headwinds and tailwinds on the straights. Man-one will accelerate if you come from a headwind to a tailwind section. Acceleration power is the same for the whole team.
  • If they put out 100 W of acceleration power, everyone in the line will have to put it, too, so that phase is not enjoyable.
  • The opposite is also true.

Possible optimisations to go faster

35:26 -

  • Resting and pre-cooling would be some strategies to implement from my hour record strategy.
  • I do not think we would find a significant amount, to be honest.
  • If we cannot get more aero and be more powerful, I think we executed it well.

General questions

General aerodynamic tips

36:39 -

  • The first thing is to test as much as possible because that is the only way you will find out what is faster.
  • Some things work for most, but not for everyone.
  • Concerning the cockpit, going narrower will be predominantly faster for different riders, but that is not always the case.
  • People have some misconceptions about this topic.
  • Triathletes might say that they need wider armrests to breathe or comfort.
  • Comfort comes from time to adapt, which could come from gym work to strengthen your upper body and neck.
  • I have not seen any meaningful data that shows narrowing the armrests impacts breathing and power production.
  • People have started to adopt higher-hand positions. It can work for most people, but you must test to validate that.
  • It depends a lot on neck flexibility as well. Higher stack and hand position and keeping a low head position will probably make you more efficient.
  • A higher-hands position tends to relax your shoulders more, allowing a lower-head position, which is where the gains come from.
  • When I was working with general people, people would come from bike fitters that use specific bike fitting systems.
  • These systems focus on putting the rider through an efficient biomechanical position instead of a fast one.
  • There is a trade-off between biomechanics and aerodynamics.
  • Biomechanics tends to have an optimal window, whereas aerodynamics tends to be more precise on whether it is faster.
  • Your body and your physiology will adapt to the stimuli you apply.
  • Even if you have a not biomechanically optimal position, your body will start to adapt to improve on that position.
  • However, you have to be careful to avoid exposing yourself to injury.
  • Lower saddle heights can load you in ways that can cause ankle and knee issues if you do not have the support and strength to ride in that position.
  • So, you should focus on the good gym work and be flexible in the right way.
  • It is easy for me to say this because at Ineos, we have staff that prepares riders for these scenarios, but it is challenging for the average rider with limited support and resources.
  • I do not want to be the person to recommend people to get away from the optimal biomechanical position and adapt. 
  • So, evaluate your limitations and understand both sides of the equation (power and aerodynamics).

Position aerodynamic tips

40:49 -

  • There are distinct positions: a tuck position (obree position) and the stretch position (superman position)
  • With the tuck position, you are trying to eliminate the upper arm or putting it in the wake of the helmet. (reduces drag because the upper arm is one of the primary drag producers on the body)
  • There is a lot of development on the fabrics or layers of fabric in the upper arm.
  • The superman position removes the upper arm, meaning you will have only skin friction on the upper arm.
  • The current UCI rules do not allow either position, so you tend to sit in the middle and optimise it.
  • Some people tend to perform better in the tight crunch position (Remco Evenepoel)
  • Others try to aim for the Superman position. It is rare in the pro peloton because you cannot achieve it within the stipulations, whereas on the women's side, you can achieve it if you are smaller.
  • In the UK scene, it is common to see stretched-out positions. Kyle Gordon is an example of that.
  • However, you must test it because neither position is comfortable, but you can train to adapt.

Equipment trends

42:55 -

  • People realise that you need to manipulate riders, put them in different positions, and do it quickly and efficiently.
  • So, in Wattshop, we always pushed for fast adjustment and integration into the setup.
  • You cannot have an optimal aerodynamic setup and adjustability in three axes.
  • Fast equipment choices allow for adjustability, where you tend to move more. (e.g. high sided arm rests give you support and move you into the position you need to put yourself into)
  • Similarly, the aero extensions provide you support in your forearms.
  • Then, you have minor things like q-factor that could allow for meaningful improvements. (it is rare for cranks to go to those narrow q-factors)
  • Cycling has evolved around a specific q-factor because the providers said that was the norm and every bike design depends on it.
  • Beyond that, clothing and helmets are the most important ones.
  • It is where most improvements come from, so we should optimise it for speed and position.
  • In Ineos, we have different helmet choices. (four different helmets and two different visors)

Other equipment optimisations

46:53 -

  • If you go from a baggy sleeveless tri suit to a well-fitted short sleeve tri suit, you will see a 5 % reduction in drag.
  • Using sleeves makes a significant impact on performance.
  • Some athletes still race sleeveless on top races, and it still blows my mind because there are massive improvements we could obtain in this area.
  • Cylinders in airflow are terrible, and there is much development in different fabrics for calf guards to keep flow attached to the leg. (optimised for different speeds according to the Reynolds number)
  • Calf guards could give you around 3 %, which significantly reduces drag.
  • Shoes might be less, depending on what you have. You would gain from covering them. There is something in shape, but triathletes do not need to worry too much.
  • Some big triathlon shoe brands perform poorly in triathlon, but it depends on what you are using.
  • Shoes are in a sensitive area in aerodynamic terms.
  • Concerning tires, rolling resistance is where you will get the most noticeable improvements. (substantial data)
  • You could see even more significant differences in the real world than in the lab.
  • In Aerocoach, they use a set of rollers, where they have a rider riding at a specific speed and measuring rolling losses and that way, calculating Crr.
  • With Bicyclerollingresistance, it is a 700mm drum where they measure the torque applied.
  • The issue with these tests is that the contact patch is different, using different roller diameters.
  • In motorsports, they do these tests on the treadmills. However, in both cases, you only measure hysteresis losses, not damp ones.
  • Tires that are good with hysteresis losses are also good with damp losses.

Dan's tire choices

54:27 -

  • This year, I rode GP 5000 TT tires. Last year, I rode Vittoria Corsa Speed 2.0 in the rear wheel and Michelin Power TT in the front.
  • Rolling resistance is slightly higher on the rear, and aerodynamics is not crucial. However, the differences are marginal (1 W, maybe).
  • A narrow tire is more aerodynamic, but measuring tire width varies depending on the tire type and the rim width.
  • On the whole, having a narrower tire at the front will outperform a wider tire because of aerodynamics and despite the increase in rolling resistance.
  • So, for example, I had 23mm in the front and 25mm in the rear.

Camelbaks and sailfish hydration systems

57:15 -

  • We needed a lot of hydration for the sub-7, and if you put it on the bike, you will get a drag increase.
  • However, a UCI rule states you cannot have it on your saddle and not in the front.
  • Camelbaks were a logical improvement for cooling.
  • The sailfish came from a Swiss aerodynamicist that has done a lot of aerodynamic development for himself, and we did some testing.
  • It varies from person to person, and it benefits athletes at different yaw angles.
  • You have a big wake behind your back, so we try to control vortex drag and reduce drag.
  • These systems were neutral at 0º yaw, and at 15º yaw, it was 3-4 %.

Current projects Dan is working on

1:00:55 -

  • I always work on projects with Ineos, but I cannot discuss them.
  • My interest now is in tire dynamics because our tires have much more than rolling resistance and aerodynamics into it.
  • So, I am contacting people in motorbikes and MotoGP because tire dynamics and tyre grip differ from a car tire.
  • It might not get a significant gain, but understanding how the tire behaves in different situations is essential and is yet to be explored.
  • Even in F1, they cannot do much research, so they take photos of the tires to understand how different loads will degrade tires.

Pieces of advice for beginner athletes

1:02:59 -

  • People start with reverse engineering because you need to have a goal, even if that means trying to understand more about cycling dynamics.
  • You should break down performance into essential components and assess the tools you have. (coach, forums, engineering mates)
  • Then, start developing procedures to improve performance (improving nutrition, training, race execution and plan, aerodynamics)
  • Implement this process in the period leading to your goal, and understand what you should expect over time.
  • You will get ups and downs in the preparation, but I think you should focus on what will improve your performance and move you forwards.
  • At the same time, you should enjoy this process. So many people get so immersed in pursuing a goal that they forget to enjoy getting there.
  • Spending six miserable months pursuing a day of happiness is probably not worth it.

Dan's book


  • My book (Start at the end: How reverse-engineering can lead to success) is for anyone that wants to achieve a goal.
  • I did it focused on sports, but there are universal things in the book that we can apply in our daily lives.
  • There are many applications for it where you have a goal, a time frame and limited tools.
  • It is too technical or long but broad and easy to understand.

Listener questions

1:07:39 -
Best stretch to become more aero
Anything about neck, shoulders, and traps, primarily.

Difference between two TT frames
At 50 km/h, probably 6-8 W. However, from old to new frames 30-40 W.

What is the craziest thing you did in the name of aero?
Basically, crossing my arms over.

Any gains from sizing up the TT bike?
A bike might not be optimal outside of its range, but it is minimal.

Are shaved legs faster? Could you cover your legs with oil?
Lotto-Soudal did that in 2017-2018 when they had hydrogels. So, there is some benefit.

Tri-spoke or deep front wheel?
I am a fan of tri-spokes when moving into disc wheels.

What made your hour Nimbl shoes better than the regular model?
They were more aero. Nimbl has a program where you can create your shoes. I am not a fan of full-carbon shoes because I find them uncomfortable, so I had a hybrid model and changed the shape slightly.

Is getting armrests narrower always better?
It is to a point. There are some other trade-offs.

Flat back or arched back?
Whatever is faster.

What is the fastest hand position?
It depends on the rider. For some, we might see improvements in others, while for others, it cannot.

If the tailwind is faster than you, is it worth being as big as possible?
You could sit up if the tailwind is equal to the ground speed. However, if you are going at 40 km/h and the tailwind is 50 km/h, the net drag force pushing you forwards will be 10km/h, which is minimal.

Dan's saddle setback

Rapid-fire questions

1:14:45 -
What is your favourite place to train?
The Velodrome. My three favourites are Barcelona velodrome, the home town Derbados velodrome and the Copenhagen one.

What is a bucket list race you would want to do?
Land's End to John O'Groats cycling challenge (42-hour record)

If you could acquire any skill in an instant, what would it be?
Python coding or the ability to design and manufacture a circuit board.


Bernardo Gonçalves

Bernardo is a Portuguese elite cyclist and co-founder of SpeedEdge Performance, a company focused on optimising cycling and triathlon performance. He writes the shownotes for That Triathlon Show, and also produces social media content for each new episode.

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