What’s holding you back : Winnats Pass in Graphs

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.

Live Winnat’s myWindsock data here

Current Winnats Pass Forecast for 2021 Nationals

How does resistance change for different riders

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.


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.

Try your own experiments and learn about your individual hill climb. Live Winnat’s myWindsock data here

Pacing : Winnats Pass in Graphs

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.

Live Winnat’s myWindsock data 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.

Big Starter3:43.2
Even Pacer3:41.5
Strong Finisher3:41.0

Let’s again look at the Last Change Delta to see how this race unfolded.


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.

Live Winnat’s myWindsock data here

Monsal Head Hill Climb in Graphs 2021

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?

Forecast as of 19:00 30th September 2021. View the latest Monsal Head 2021 Weather Forecast.

The Forecast

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.


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.