Ben Norbury is four times Manchester & District Middle Distance and Best All Rounder Time Trial Champion from 2016-2019. During this time he developed software to eliminate uncertainty of the weather conditions out of his pre-race preparation.
You already cheat the wind with myWindsock Premium, but now you can get even more aero with $50 off a Notio! Measure your CdA in real time with the world’s premiere on-bike aerometer and maximize your gains by testing your position and equipment for the ultimate aero advantage.
Not already a myWindsock Premium subscriber? Upgrade now from only £9.99/$14.99 per year, to receive this offer. Learn more
Attach a Notio to your bike and you’ll be recording live air speed data. With this data, your aero computations are enhanced with moment by moment calculations. Combine a Notio with myWindsock Premium analysis and you’ll have the ultimate package for aerodynamic analysis*
*Notio data analysis in myWindsock is expected January 2022.
How Aero Analysis helps you go faster
To go faster, you can either produce more power, or become more efficient. One way to be more efficient is to move through the air with less resistance. Making changes to your position, or choosing better equipment, can lead to big improvements in your aero efficiency and speed.
myWindsock Premium enables you to track your aero changes and make informed choices.
We measure your efficiency in CdA. The more efficient you are at moving through the air, the lower this number will be. Typically a road cyclist will be between 0.300 – 0.400. A racing cyclist on a road bike will be in the 0.250-0.300 range. Time trial cyclists will be even lower, with some specialists below 0.180.
Premium gives you many more fascinating insights into your activities. Here is a run down of some pretty cool things to look at post-ride.
Feels Like Elevation
A Feels Like Elevation chart.
Metres or feet climbed on any ride gives an insight into how tough the terrain was. Bragging rights are given when huge elevations are ridden. We’ve developed Feels Like Elevation. A combination of the wind and elevation to give a true picture of how tough a ride was.
Whilst the elevation profile indicates it’s down hill out and up hill back, combine the feel of the headwind the profile looks a lot different.
Headwinds will increase the elevation by the relative effort to ascending hills. Similarly a nice tailwind will make the road feel a little more down hill and the elevation profile is corrected to reflect this.
The CdA Profile depicts your aero efficiency during your ride.
Just how aero are you? Aerodynamics can now be tracked, just like your FTP and other performance metrics. Having an eye on these numbers during training keeps you in the competitive athlete mind set. Aerodynamics is reported in a metric called CdA. The lower your CdA is, the faster you will go for the same power.
Go further this Winter and actively work on your aerodynamics. Train your ability to hold your position.
Pro tip: Find a repeatable loop of a around 10-20 mins, where you can safely focus on your position. Complete 4-5 loops and see how your CdA alters on each loop. Do you start to notice a change with fatigue? See how steady you can keep the CdA.
Weather Impact is a key myWindsock Premium metric. It combines all enviromental factors to give a definitive rating of how great the a cost or benefit the weather was. We add this metric to your past rides, routes and very interestingly Strava Leaderboards.
On every Strava Segment effort we record the Weather Impact. On your latest activity use the Premium Strava Segment Filter to reveal the interesting Segments you rode through. Then access the Leaderboards, view how your best efforts compare and the top 10 Weather Impacts.
Doing just enough to elicit the maximum training affect is the most efficient way to train. myWindsock can help you pick out the best locations for your intervals and plan their intensity.
I’ll show you how to get an interval plan looking like this. Three intervals depleting similar amounts of W’, your work above Critical Power.
Creating the intervals
I begin by picking a chart that will assist us in planning our intervals. For this paticular session, I am attempting to deplete the same amount of W’, or Kilojoules above Critical Power, on hills with differing lengths. I would like to know how much power to put out on each hill to deplete the same Kiljoules of work above Critical Power.
As I am interested in the W’, it makes sense to plan our intervals with the W’ Bal chart.
W’ Balance Chart is under Power in the Chart Menus
Next I simply drag, or highlight a selection of the chart. When I am happy the correct part of the route is in the chart view and highlighted on the map, I click “New Interval”.
Click New Interval when you are happy with the selection.
I now add the interval parameters. I’ll start with 340 Watts.
I finish by clicking “Save Interval”. I then will repeat this for the next two hills, creating three intervals in total. Remember to click “Apply Changes” to reveal the result of the intervals.
Three intervals, W’ Balance graph shows the depletion of energy above Critical Power.
However due to the differing length of the hills this workout wouldn’t deplete all of the require W’ for the session. Let’s see if we can even them up.
Clicking the edit button on the interval marker will open the interval edit.
Opening up the interval editor, we can add a few extra Watts to each of the hills we were short of Kilojoules. After a little adjustment we can now see even W’ depletion for all three intervals/hills.
The Navigator menu reveals key selections including Intervals we have created.
I now have a power plan for the interval training session. Let’s see what couple more charts tells us.
Power Profile shows the planned power for my interval sessionRolling Weight Power, how our Weighted Power evolves during the session.
The above Resistance Distribution, is based on our estimates of a male podium finisher. We’ve estimated this to be an athlete with an output of 7.7 Watts/kg. With a total mass of 70kg, averaging 540 Watts. Our predicted time for this rider is 3mins 5 seconds.
The forces acting against each rider is very individual. By far the greatest force is gravity. It is no suprise that as we increase a rider’s weight, so does the proportion of energy required to move the rider up the hill. However there may be some interesting changes to the distribution of the other resistances.
Let’s face it, at 15% average, gravity is a huge part of the battle between Watts and Speed. However, with a few trips up the hill for our myWindsock Virtual Rider, we can see how each rider’s morphology has an individual mix of additional resistances to pay attention to.
Increase Mass of Rider, bike & equipment
Keeping our Watts/Kg the same, let’s see how three riders of 60Kg, 70Kg and 80Kg compare. Here we see an exchange in distribution between Air resitances and Gravitational resistance.
Note, Gravity is using the right side axis. All others on left side axis.
Look at how air resistance decreases, whilst gravity increases as a proportion of the rider’s energy consumption. Heavier riders are less affected by changes in the wind. See also, despite the power ratios being the same at 7.7Watts/Kg, a larger rider actually rides the hill quicker.
Increase Rider’s Power Output
Taking a 75Kg rider we then altered their power from 5Watts/kg up to 8Watts/Kg. As the power increases, the proportion of Air Resistance increases the most.
Note, Gravity is using the right side axis. All others on left side axis.
Here we see a similar exchange between Gravity and Air resistance. It’s interesting to observe that a less powerful rider will be impacted more by their bike and equipment weight.
Also see that as a rider becomes more powerful, Acceleration increases as a proportion of energy expenditure. This is the energy required to change the rider’s speed. As power increases, rotational weight becomes more important.
Conclusion
You may not be able to change much about your morphology. At 6ft 2inches, I wish it was something I could train around September and October. However understanding your individual fight up the hill may give you some idea as to where to focus for that extra edge.
Our myWindsock Virtual Rider has tirelessly ridden the course to produce some super geeky data. Virtual Riders, ride the course as instructed by you. Give them a 1000 Watts, they’ll knock out 1000 Watts until you tell them to stop. The best thing is, they never get tired.
myWindsock Virtual Riders testing every pacing scenario
In this article we look at how best to pace the hill climb. We recommend following along and creating your own Virtual Rider with your own anticipated power, weight and up to data weather.
You may want to jump straight to the results of our pacing investigation, it is here.
Let’s get straight to it, big start or big finish!
Hill climbs all have their unique pacing strategy. A time trial isn’t a straightforward physical test. Dynamics of the course, such as gradient and air speed, should be considered when planning your effort.
Luckily, we have a simple method to demonstrate where you save the most time for the additional power.
Now, not all courses have the dynamics or weather and elevation profile to produce big variation. With “consistently steep” as Winnats description we’re not expecting dramatic changes from pacing. However a couple of seconds is likely up for grabs.
Quick experiment to get us started
First, we begin by simply adding a little bit more power to our Virtual Rider’s profile. In this example, we give our Virtual Rider an extra 10 Watts. As you’d expect, this reduced our Virtual Rider’s time. At 75kg, 10 Watts reduced the time by ~4 seconds.
The purpose of adding the additional power is to find where it had the greatest effect on our time. Next, we look for clues in the ‘Last Change Delta‘ (LCD).
Last Change Delta
Last Change Delta – every time you make a Virtual Rider change, a comparison to the previous setup is provided.
The grey Trend Line shows the average time gained or lost by your last change. The green Delta Line, is indicating we are ahead and by how many seconds.
The Delta Line would be red if we were behind. Up to ~300 metres the Delta Line is actually 0.5 seconds behind the Trend Line. This means, to this point in the race, we were gaining time slower than the overall trend. Remember we are still gaining time, just at a slower rate.
After 400 metres, or around the right hand bend, the two lines start to converge again. This indicates we are now gaining time quicker than the overall trend. We want to capitalise on the parts of the course our Watts gain time at the greatest rate.
Sometimes the variance from the overall trend is difficult to spot. The Delta Variance graph helps us to do this.
The Last Change Delta Variance – catchy name.
Let’s have a race
Let’s compare two riders, one with power ascending and the other descending. We must be sure our Weighted Power is the same across each Virtual Rider. To ensure equal power I’ve tweaked the start and end points of our intervals. Our riders are 75kg including bike.
First rider up, the Big Starter
This rider has gone hard from the start and then faded to the finish.
Next up, the Strong Finisher
This rider has tried the reverse method, building from 450 Watts to 510 Watts.
Who wins?
Let’s remember, we have adjusted these two riders efforts to ensure the same Weighted Power of 483 Watts.
Competitor
Time
Big Starter
3:43.2
Even Pacer
3:41.5
Strong Finisher
3:41.0
Let’s again look at the Last Change Delta to see how this race unfolded.
Conclusion
Measuring your effort at the start is likely to yield a better result than getting too carried away. The same overall power but differing pacing strategies resulted in a 2.2 second gain by the Stronger Finisher. Interestingly the Even Pacer, was only 0.5 seconds behind the Stronger Finisher. Just don’t fade at the finish.
Things to try, how much differential between the start power and finish. I did do a bit of tweaking and found a 60 Watt spread had the best return for the 75kg rider. I recommend trying this out for your own power and weight. See what happens when you increase or reduce the spread of Watts.
It’s the iconic Monsal Head hill climb this Sunday. Let’s take look at the course and it’s conditions with a few myWindsock Graphs. Could this be the year Malcolm Elliotts 1981 Men’s course record (1min 14.2secs) is bettered?
Let’s start with the basics. The overall forecast is, cool temperatures and a strong WSW wind, gusting from 18mph to 32mph.
A crosswind start turns gradually into a headwind by the finish.
The Course
The following myWindsock dynamics are computed for a record equaling 1min 14sec ride. 80KG total mass, 880Watts, 11Watts/kg.
For the first 12 seconds, most of the rider’s Wattage is contributing to accelerating to 45kmh. Then the gradient bites quickly.Negative Air Speed during the first 30 seconds reduces air resistance. A higher air speed than ground speed, during the steepest section, increases air resistance.Weather Impact% shows how much additional energy would be required to match the conditions of a weatherless day. Overall the wImpact% is 2.2%. This means to equal a weatherless day’s conditions, 2.2% more Watts would be required.
11Watts/kg is 11Watts/kg, right? Wrong.
On a climb like Monsal Head and the forecast weather conditions, a heavier rider with greater Watts, will better a ligheter rider who has the same 11Watts/kg required to hit the 1min 14.2Sec. The Delta Comparison Chart shows how the lighter rider loses time to the heavier rider.
Red line shows 70kg rider losing time to 80kg rider. Eventually losing 1 second overall.
Why is the lighter rider slower? Let’s compare the resistances.
The lighter rider has a greater proportion of their energy overcoming Air resistance than the heavier rider. This is because, generally speaking, the aerodynamic drag does not increase proportionaly to the rider’s weight. The additional wind resistance will act in the heavier riders favour.
So, how many extra Watts would a 70kg rider require to match the 80kg rider’s time?
An extra 0.2Watts/kg (15Watts) would be required to match the time of the 80Kg Rider. Air resistance mostly consumes the additional Wattage.
How good did Malcolm Elliott have it?
Using myWindsock.com historic weather, we can look back to the recorded weather conditions for the 1981 Monsal Head Hill Climb.
18.9mph WNW.Significant 8km/h reduction of air speed in first 45 seconds of ride.Overall the myWindsock Weather Impact% for 1981 was 0.1%. This is favourable compared to the 2.2% wImpact% forecast for Sunday.
Big question, in 1981 what were the Watts/Kg required for an 80kg rider to record a 1min 14.2sec rider?
10.44Watts/kg. But, big caveat… This was 1981, clothing, tyres and the bike would have been less favourable than today’s equivalents.
Conclusion
The current forecast is significantly less favourable to that of 1981. This will make a record ride even more exceptional should the 40 year old record fall.
Check out the Monsal Head course yourself and make your own experiments.
Top reasons to load a Strava Segment into myWIndsock.com.
1. To view the current weather conditions
Athletes who are prepared better mentally will perform better. Weather Impact and other key metrics reveal the true effect of the weather on the course, learn more about wImpact%.
2. Leaderboard Weather Conditions
Knowing what the conditions of the top 10 were can put into context an athletes performance. The Windrose at the top of the Leaderboard shows the most frequent wind direction of the top 10. Key metrics such as wImpact% quantify the affect of the weather for each effort.
3. Experimenting with Pacing
Discovering where to push the biggest Watts for an effort can be key. The combination of ascents, descents, headwinds and tailwinds make each course a unique challenge to be experimented with.
4. Segment Windsocks
Knowing when to attack a Strava Segment is key to getting the best result for an athletes efforts. Waiting for that perfect moment is key to glory. Segment Windsocks monitor Strava Segments for the optimum conditions. Find out more about Segment Windsocks.
5. Predicting their time
Timing a big effort is crucial to an athlete getting everything they have out on the road. Knowing if it’s 2 minutes to go, or 2.5 minutes, ensures every Watt is released in time.
Discovering how your weather compared to others in the top 10 of a Segment, reveals the truth about your effort.
It was my first time out on the JC19 course held by Weaver Valley. It’s a challenging course, mostly due to the Cheshire pot holes putting the word ‘trial’ in ‘time trial’. The result landed me a top 5 on the course’s Strava Segment. That was a suprise! I didn’t feel it had gone paticularly well. So my question this evening is, were my conditions this evening better than the rest of the top 10? Were my efforts flattered by the time trial course’s weather conditions?
The Weaver Valley 10
One of the first features of myWindsock was to compare segment weather. The technology has come along way from simply stating wind speed and direction. wImpact% now shows the percentage of energy required to match the conditions of a windless day. So a wImpact% of 5% simply states that you would require an additional 5% more power to achieve the same time on a weather neutral day. [Learn more about Weather Impact]
So how about tonight’s effort that landed me a top 5 on the Leaderboard. Did I have a lower wImpact% than the rest? meaning my conditions were better. Time to checkout the Leaderboard Weather [Find out here how to do this Leaderboard Weather].
Well a weather impact of wImpact% of 0.8% is very good and as we can see it’s the best conditons of any in the top 5. So I think I can say I chose a pretty good day to go along to Weaver Valley Club 10 to try out the course. Next time out I think I’ll be a little more settled on the bike. My CdA measured 0.010 greater than my most recent events [Find your Ride’s CdA] and my power was a bit low. So it’ll be good to go back and have another trip around the Weaver Valley 10 mile.
In tonight’s race I was hoping to move another step forward with my aerodynamics. In my race plan, Crosswindy JC/27, I was predicted a 21:14. However a complete stop a mile into the race and I still finished with a 21:12, let’s find out why!
At least my stop was early in the time trial, so I can cut this out and get some decent aero data. I did this by creating a new Interval [learn how to create intervals]. This allows me to isolate that part of the ride and ensure my CdA analysis is not including any of the braking or the strained and overgeared return to race speed.
Am I getting back my aero…
From the start of this season I’ve been struggling with getting my head comfortably low. So I’ve been making some methodical alterations to my setup. Changing just one thing at a time. First of all I swapped my Aerohead to a pointy Giro Advantage helmet. I did this as I felt the helmet’s tail may be the best band aid while I figure out why I can’t get my head below my shoulders. There was a small aero improvement with the Advantage helmet.
I then looked at why I couldn’t tuck my head like I have been able to in previous years. At first I put this down to decreased flexibiity during the off season. I eventually decided this could be due to repositioning the saddle a little more reawards. I did this as I was having issues leveling the saddle. In training I didn’t feel much difference from the change. In racing however I think it could have been a tipping point.
I’ve been using myWindsock CdA analysis of my time trials to track all my changes and the results are measurable. Having raced with my saddle forward by 1.5cm in the Giro Advantage pointy helmet I thought it best to see if it is still the correct choice. [Learn how to measure your CdA]
Success! The more forward position is further improved by returning to my Aerohead helmet.
Sprint finish
In my race planning I wanted to know whether it was better to be out of the saddle at the finish. I decided, from my analysis, the extra power cancelled out the aero penalty. So I jumped on the pedals over the small hill to the finish. It just felt right at the time.
Was it a quick night?
Overall the wImpact% was 1.3% which is very good. In past events on this course the wImpact% has been as high as 7.2% [learn more about wImpact%]. The crosswind added an additional 4 metres of ‘Feels Like’ elevation gain which again isn’t too bad when compared to the additional 18 metres last time at this course [learn more about Feels Like Elevation].
You can analyse all of your time trials or training ride with myWindsock, find out how to get started.
UK Time Trial Events
