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 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.

Top 5 reasons athletes view a Strava Segment on myWindsock

Top reasons to load a Strava Segment into

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%.

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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.

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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.

rolling delta-graph

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.

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Find out how to load a Strava Segment into myWindsock.

Discover the truth, was it a fast day or not? Revealing post race analysis.

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?

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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].

Screenshot 2021-06-16 215506

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.

Am I getting back my aero? : Post race analysis

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.

Screenshot 2021-06-08 234707

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.

Crosswindy JC/27 : Club Time Trial Prep

Before our Tuesday evening club 10 I always look up our time trial’s forecast. WIth some experimentation there may be some extra speed available. At the very least knowing what to expect when out on the road is always useful. It’s super easy to do, you can find yours on the UK Time Trials Club Events page. This is where we have listed all the UK’s evening club time trials ready with forecasts.

This week’s forecast

The feature for this week’s club 10, on our JC/27 course is a moderate crosswind. To get the best data for the course I need to update my Virtual Rider with my latest performance data. To do this, I will use the Suggest Power Settings button and Select Best Effort [Learn more about Suggest Power Settings].

From my last time trial (Post race analysis: M&DLCA J2/3) I discovered my CdA has improved to 0.202 so I’ve entered that in the Aerodynamics of my Virtual Rider [Learn more about Virtual Rider Settings].

This gives my Virtual Athlete a time of 21:14. Whilst the time is interesting to have as a goal for the race, it is more about simulating the race for better data insight.

How will the ride feel?

The first graph too look at is the ‘Feels Like’ Elevation Profile chart. This is how the Wind + Gradient combined will feel. [Learn more about Feels Like Elevation].

Screenshot 2021-06-07 173336
A crosswind will often cause Feels Like Elevation to increase across the route, as in it’ll feel harder than a windless day. This is because air moving across you, even if it is not directly head on, still increases the air flow over you and resistance. So this is the case tomorrow, the day will Feel a little headwindy each way. The good thing is that the angle and speed of the wind for the time trial creates just a small increase in Feels Like Elevation across the ride.

Splitting Out from Back

I want to see how a 10 Watt difference between the Out and Back will change the Virtual Athlete’s time. To do this I create an Interval for both the Out and Back portions of the ride [see how to Create Intervals].

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Next I customise the Out interval with a 5 Watt increase and reduce the Back interval by 5 Watts. Now let’s see how the reversing the power output to higher Back than Out, changes the time prediction. There is just 3 seconds difference between the two stratgies, not a significant change. However I will ensure I am well warmed up so that I have my top end power ready from the start.

One last experiment…

I’m always tempted to sprint out the saddle in the final minute of this course. It’s up hill and begs me each time to leap out of the saddle. But the speeds are high, still averaging over 25mph. There is however a 50 watt difference between my out of saddle finish and my seated sprint for the line.

So let’s do a little bit of modelling. I’ve entered my aero finish params as  below.

Screenshot 2021-06-07 222557
But now I need to modify this Interval for an out of the saddle effort. But was is my out of saddle CdA. Luckily I did succomb to the urge to leave my aero position in a previous TT. So I have a Live CdA line to give me some guidance. This puts me at around 0.280. Not too bad but I am still leaned forward and attempting to maintain some aeroness.

Screenshot 2021-06-07 223121
Highlighted finish Live CdA

So let’s put those numbers in 480 Watts with a CdA of 0.280. The result…

Screenshot 2021-06-07 223818Interestingly the 50 extra Watts merely compensates for the loss of aero. So tomorrow I’ll just go with what feels natural, knowing there’s nothing to be gained or lost there on this occasion.

Out of curriosity let’s move the forecast forward to later in the week to see what a 10mph headwind rather than the crosswind would do to the same experiment. This time a slightly different result with a 1.2 second benefit to staying in the less powerful but more aerodynamic position.

Last change delta chart shows the time lost.
Last change delta chart shows the time lost.

How will my average speed develop during the ride?

The predicted time indicates an average speed of 46kmh. Now if I went straight from the start expecting to see that number on my bike computer I’d be burying myself pretty deep. This is why studying the Rolling Average Speed Graph is so useful. We want to know how we are doing against the plan. I usually check at the very least my expected average by the turn.  [Learn more about the Rolling Average Speed graph]

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There isn’t a significant drop from the turn to the finish if all goes to plan, just 0.5kmh. So fingers crossed it’s a case of get to the turn an hold on.

To start analysing your club’s evening time trial, find it on the UK Time Trials Club Events page.

Post race analysis: M&DLCA J2/3

Today’s race was the M&DLCA Invitational. The weather can be summed up simply as HOT! This did mean however the air density would be at least a bit lower than the cooler evening club time trials I’ve been racing. The J2/3 is not known to be a quick course, with the finish 14 metres higher than the start. However, with a South Westerly wind and an Easterly finish, just as we had today, it can offset some of the positive elevation gain.

Screenshot 2021-06-05 184259


Aero Check, what was my CdA?

As usual post race, the first thing I look at is my CdA. I left my Garmin running from the start of my warm up, which was actually mostly trying to keep cool, so I need to select the race from the Activity Navigator [Learn how to use the Activity Navigator].

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Once I’ve selected my race lap or segment, my summary stats including CdA are recalculated. But the average CdA number can sometimes not give the full picture so it’s always worth viewing the CdA graph. [Learn more about finding a race CdA]

Screenshot 2021-06-05 181544

As you can see, highlited line has a small step down. This is usual with an out and back course as the loop that controls the CdA line starts reading opposite on the road to where the ride finishes to complete the loop. So we ignore that first bit of the line. The line reveals I had an average CdA of 0.202.

Since starting back racing my CdA has been much higher hovering around 0.215-0.220. So I am happy to see it going in the right direction with a small saddle tweak and a helmet change.

‘Feels Like’ Elevation for Time Trialists

‘Feels like’ Elevation allows you to mentally prepare for the event you have coming up. A huge part of racing is being prepared and knowing the course you are going to be riding.

With this graph and metric you will get a perspective on the effect the wind will have. This will give you a better and clearer image on how to pace yourself during a race so you don’t burn yourself out. Our graph allows you to visualise the wind, like you would the summit of a hill. Have a look at this event The S6/10 Tri-Logic Event time trial.


This course is up hill on the way out to the turn and downhill on the return. However with the added tailwind on the up hill and headwind on the downhill, on this particular day, the course would feel flipped. The uphill with the assisted tailwind would require less effort and power and would actually feel like you were going downhill.

The headwind is very harsh and strong on this particular day and would make the downhill would ‘Feel Like’ an uphill effort. Find out more about ‘Feels Like’ Elevation graph and metrics.

We have all the UK Time Trials ready for forecasting each week. Discover the ‘Feels Like’ elevation for your next race in our Time Trial Events section.