It is somehow already October which means only one thing, it is National Hill Climb Championships. At the time of writing, the race is 11 days away which is a bit far for an accurate forecast but close enough for a detailed course review. This year the champs course is on Porlock Toll Road in Somerset
This image, from the Porlock Weir tourist board’s website, shows a portion of the bottom of the climb. It’s a scenic climb with panoramic views across the Bristol Channel – though we can’t imagine riders will spend much time taking them in during the race.
Porlock toll road is a 4.1 mile climb – one for the long climb specialists. It’s a relatively shallow climb with a decent range of gradients that we’ll go into later, but our best guess (though it’s heavily wind dependent) is that the men’s race will be won in a time around 13:45 and the women’s in a time of around 17:00 (or, wind adjusted equivalent times). All the fastest climbs have been set on days with a strong tailwind. The shallow gradients mean the wind can impact times up here, but this is offset by the shelter most of the way up.
The map
With more than 10 corners and two hairpins, this is a twisty climb. Gabe Dellar, hill climb hitter and friend of myWindsock, told us there’s two points where he had to stop pedalling while riding up the climb when he did his course recon.
In the 1960s it was actually used as an RAC Rally stage, one of the fastest drivers at the time being the late Pat Moss, sister of Stirling Moss, who completed the 4.1 miles in 3 minutes and 56 seconds which is an average speed of over 100kph.
With more than 10 corners, some quite severe, it’s amazing the speed anyone can drive up. As the gradient is very shallow, some riders will have to stop pedalling on their way up.
The profile
This road is a shallow climb. The speeds will be high and it’s one for the lightweight aerodynamic enthusiasts. The sharp corners are sharp enough that a second or two can be gained or lost from bike handling. Tyre choice will be uniquely interesting if it’s wet on the morning of race day – which is looking possible.
A smooth climb that’s relatively sheltered. We can see from the topological elevation being extremely close to the geographical elevation the shelter along the side of the route protects riders effectively from the wind.
The red line here represents the power expended due to gravity, the white line – power due to aerodynamics. Obviously, as this is an up hill race, gravity is the primary resistive force but aerodynamics matters a lot – enough to be the difference at the end of the day.
The road surface
One report we heard back from Gabe was that the road surface on the climb is not perfect. This isn’t a surprise for a small lane in the South West of England but it’s worth bearing in mind. There is also a cattle grid on route. Our tip here is to ride a recon, of course – but with this being a toll road it will cost you a quid if you want to ride up. If you’ve spent all your money on drills to save weight on your hill climb bike but are concerned about the road surface, you can check it out on Street View.
We’ll post a detailed forecast late next week, with predicted times and pacing advice as well as physical wind features.
It’s Ironman World Championships week again and this year the men and women are back in the same place, racing on the same day – just like the good old days. Last year was the final rendition of the split competition, with the men’s race in Nice and the women in Kona but this year we are all back in Hawaii – hooray!
The race has moved around the calendar a bit in the past and the weather can change a lot depending on when it is, which is what makes this course so interesting for myWindsock users. Its usual slot of the 2nd weekend in October was ditched in 2024 – part of the reason for the fast time though the trend of the past decade in race times is clear.
The famous bike-course wind comes from the Kohala coast near Hawi, where the trade winds and the island’s terrain produce strong gusts (the “mumuku” winds).
The wind on the big island of Kona has already seen off one victim, with defending champion Casper Stornes being taken out by a big gust.
The trend in results dictate that the men’s course record almost certainly is going to have to be broken by the winner. Lucy Charles-Barclay’s over-performance of 2023 means that the women’s race could be won without necessarily breaking the record, though it’s a fast day as we’re about to see so it’ll probably go down too.
This graph shows the trend in overall finish times in the Ironman World Championships for the past 10 years. Each year improvements in aerodynamics and nutrition are causing the race to get faster and faster. Kienle’s winning time from 2014 would have only just cracked the top 30 in 2024.
The Ironman Hawaii course is really boring. It has achieved legendary status as it is pretty hot and humid which has caused some blowups and meltdowns over the years – though this is mostly down to the way people race it and not because the course itself is inherently crazy. Huge advancements in pacing, nutrition and aerodynamics have neutralised a lot of the challenges too.
The course is essentially an out and back along a coastal highway. The trade winds come from the land side and there’s a volcano which kind of shelters the riders from it. The wind can be strong, though on race day the forecast is for extremely low wind.
The only time the athletes have to really do anything other than look at their power meter is through town. They do a mini loop to get onto the main highway and a mini loop when they get back. What little wind there is forecast to be this year is sheltered from the buildings as you can see with this surface friction layer on the myWindsock map.
The elevation profile is equally simple. There’s one hill – the road up to Hawi. It’s not even steep. It’s a huge motorway drag strip. It is a point on the course where it’s possible to make a difference and split groups though so expect moves to go during this section of the course.
How to break the course record – Women
The women’s bike course record is a time of 4:26:07 set in 2018 by Daniella Ryf. This was another fast day with low air density and pretty low peak wind speeds. We will see what it would take in order to ride a 4:25 for a woman with a system mass of 70kg (including bike and kit) and a cda of 0.2 with Saturday’s conditions. The candidate most likely to break the course record is Taylor Knibb, who recently finished in the top 15 of the World TT champs and has a reported FTP of around 300W.
Conditions suggest a rider of around Knibb’s size with an average cda of about 0.2 (with some variation on the climbs and descent) will be able to ride 4:25:29 with an average power of 242W – roughly 80% of Knibb’s reported threshold. That is around the upper limit of the power professional athletes ride in Kona relative to their Critical Power but it suggests a course record is not unlikely.
How to break the course record – Men
The men’s course record was broken more recently, with Sam Laidlow riding a 3:57:22 in 2024. Laidlow is around 75kg so we will assume a system mass of 85kg (bike plus kit plus rider plus water). The question is, do Saturday’s forecasted conditions make a 3:57 or lower bike split impossible to obtain with human watts?
A 3:57 this year, as the forecast stands, will require a power of 330W. This is on the high side but not unheard of for Ironman athletes at World Championships. The men, being at the absolute front of the race, will also have more motorbikes in front of the front group – making a fast split easier to achieve with less watts than this.
If I was a betting man, I’d say every single course record will go down this year apart from the men’s swim course record. This is due to a unique combination of conditions, field strength and likely race dynamics. 2026 will probably be the fastest Kona ever!
Some of you may have noticed that myWindsock has had a bit of a new look in the past couple of months. Along with our renovation comes a number of new graphs and charts to help you analyse your rides, routes and races. Today, we’re going to go through our top 5 graphs and charts that are new, or revamped, on myWindsock.
1. Timeline view
The timeline graph allows you to view your ride as you’ll feel it on the road. It includes topographic exposure, elevation changes, power advisor, wind significance, estimated model error, CdA estimates, topographically adjusted wind speed, power settings and more. By pressing the plus bottom in the bottom left you’re able to add new values to the timeline view. The timeline view can be accessed via the arrow in the navigation bar at the bottom of the screen which expands it into what you can see here.
2. Modelled Power Components
The modelled power components graph is a revamped version of a plot on the old myWindsock platform. It tells you which component of resistive forces are slowing you down out of aerodynamics, rolling resistance, gravity and acceleration. It tells you how many watts you need in order to overcome that resistance. For example, you can see where the gravitational force goes way below 0 – this coincides with the course going down hill.
3. Conditions Evolution
This graph is visible to you in the top left hand side of your screen. It shows you how temperature, wind, rain and air density evolve throughout the day. This is good for both deciding when to leave the house for your ride, as well as checking if you’re disadvantaged with your start position in a time trial.
4. W’ Balance
This is another revamped plot from the original myWindsock platform. It tells you how much energy you have during a time trial when it comes to going over your threshold. When you go over threshold, you deplete your W’ which takes time to re-charge when you go back under threshold (for example, a period of you not pedalling on a descent).
5. Adding your own
A key feature of the new platform on myWindsock is the ability to add extensions. As part of these, you can add the output of these extensions as graphs and add them as custom data panels.
There are significantly more than 5 plots and new features on the myWindsock surface platform. If there are any there that we’ve not explained, myWindsock will explain it for you.
The “Explain This” button can be found beneath every graph, where myWindsock’s AI will explain every aspect of the graph.
In the past week, Remco Evenepoel won his fourth consecutive World Championship in the time trial. He rode the 39km course at an average speed of 52km/hour – an entire kph faster than his closest competitor. It’s looking really hard to see how someone could actually beat him in the medium term. This got us thinking, how hard actually is it? How many watts are needed at different drag coefficients to beat Evenepoel?
It’s clear that Remco is on another level to everyone else. They’ll all be scratching their heads wondering how to beat him…
How good was his performance?
Fiddling with the various values that go into myWindsock, we were able to achieve a time on the exact GPX file that he uploaded to Strava that’s just two seconds off what he actually uploaded.
Evenepoel has a reported FTP of 425W and we’ll assume a system mass (rider + kit + bike) of 72kg, not that is makes a huge difference on such a flat course. We will set CRR values and drivetrain resistance values that assume he’s on the fastest possible set up. Presumably they weren’t using slow tyres…
This is the modelled average cda of Remco, including some sitting up for cornering and more. The minimum cda is the value recorded in the wind tunnel and reported.
Using the file that Remco uploaded to Strava, we can play around with the values until we’ve matched his time. This gives us an average cda of 0.194 during the course of the TT (however, this includes all sitting up, cornering etc) so during the long flat periods of the TT his cda will be significantly lower. Evenepoel’s reported cda is 0.17 in the tunnel so this chimes with our estimate including him sitting up and cornering.
What happens to the power requirement as we change the cda from 0.194 up to 0.21? This represents a decrease in aerodynamics of just 3.5%.
cda
Power needed for 45 minutes (W)
0.194
391
0.200
401
0.204
409
0.210
419
This table of values assumes that every single other aspect of your set up is exactly the same as Evenepoel including system weight, rolling resistance and such. In reality, it’s very unlikely that these numbers would exactly match.
The performance by Evenepoel required him to do an average power of 391W which is 6.2W/kg. If Evenepoel was just 3.5% less aerodynamic the required relative power would suddenly be 6.65W/kg. While W/kg is not particularly relevant for time trials, it does showcase the vast difference that a small change in aerodynamics can make in power requirement.
What about an 83kg rider with a reported cda of 0.19? Asking for an Italian mate…
Ganna rode at an average speed of 51.3kph during the race. Adjusting all of the other values to meet this speed comes out at a required estimated average power for Ganna of 440W for his roughly 46 minute effort. This is in line with Ganna’s reported threshold values. In order to achieve the time that Evenepoel did, we can adjust the power values as Ganna is extremely aerodynamically optimised. It turns out, he’s 15-20W short.
Those of you reading this in the UK will, undoubtedly, have had multiple occasions in your life where you’ve wished it was possible for you to change the weather. Well, we have good news for you. For the low price of your annual myWindsock subscription you will now be granted this power. Here’s how…
Open up myWindsock’s Surface platform
Scroll down the panel on the left hand side of the screen
Click on the “Weather Override” drop down menu option
Input values to change the weather
Unfortunately, for legal reasons, we are only able to change the weather within the course simulation on myWindsock, we are not able to adjust the weather outside. That said, it’s still interesting…
You go faster when it’s hot
The human body doesn’t love hot temperatures, especially a British one. That said, there’s an offset – as the air resistance of a bicycle decreases when it warms up so you need to produce less power to go the same speed. Bare with us while we do a little bit of maths.
This expression tells us about the power needed (P_aero) to ride at a given velocity (v). You’ll notice there’s a little symbol that looks like the letter p, that’s a Greek letter called rho and in this equation it represents air density. What this tells us is the power required to ride at a specific speed, v, is directly proportional to the density of the air.
Now, air is made up of tiny little particles, mostly:
Nitrogen molecules ((N_2)) — 78%
Oxygen molecules ((O_2)) — 21%
Argon atoms ((Ar)) — 0.9%
Carbon dioxide molecules ((CO_2)) — 0.04%
Water vapour molecules ((H_2O)) — variable
When it gets really hot, all of these particles whizz around quite a bit faster which means in every cubic meter of air, there’s actually less particles than when they’re moving slowly. When you’re cycling, you have to push each of these particles out of the way – that pushing is the force we feel from the wind and we call it “air resistance”.
Air density is proportional to atmospheric pressure (P – not power this time) and inversely proportional to temperature. When temperature goes up, air density goes down (if all other things are fixed).
This is why you go faster when it’s hot. In real life, the temperature does impact your ability to produce power. But on myWindsock – we can just pretend that isn’t the case…
How hot does it need to be for me to break the Poggio KOM?
The Poggio di San Remo segment on Strava is held by Tadej Pogacar and Filippo Ganna who some how managed to ride up it at 39kph. Neither of them share their power data on Strava but presumably they did quite a lot of watts.
As we’ve already discussed, air resistance decreases when the temperature goes up. That means, you ride faster for the same watts. Imagine a 76kg rider on a 6.8kg bike doing 500W on this climb in a relatively aerodynamic road bike position, with a cda of 0.23 on a windless day that’s 30 degrees. This is 6.5W/kg for around 6 minutes, so pretty good but not alien level world tour numbers.
This gives us a prediction of 6 minutes and 16 seconds. A pretty good time on this segment. But what happens if we change the weather?
Getting the perfect day
We are now going to calculate the conditions required for our imaginary rider to get the KOM on this climb. We will start with the wind…
The Poggio di San Remo segment is twisty enough that if we turn the wind up too much, the headwind section slows us down more than the tailwind speeds us up…
Wind Speed (m/s)
Segment Time (min:sec)
0
6:16
5
6:09
10
6:07
15
6:12
As it turns out, 10m/s is the optimal wind speed (at 30 degrees with this cda) on this climb. Any faster, and the headwind section slows us down more than the tailwind speeds us up.
We need to find 37 seconds to get that time down to 5:30. We will use our optimised wind direction and wind speed to increase the temperature until we find that extra 37 seconds.
Temp (degrees C)
Segment Time (min:sec)
30
6:07
40
6:05
100
6:00
Well, looks like we aren’t getting that KOM then…
It turns out, a regular human has absolutely no chance competing on the Poggio with Ganna or Pogacar. Ah well, we tried.
Every grand tour used to contain a long flat time trial but these days they’re becoming more and more rare. Truthfully, we miss them and the organisers of the Vuelta must have been reading our minds because they’ve bought it back, though we’d prefer for it to be 50km like the good old days.
After making their way out of El Puerto de Santa María, riders will sette into their pace for a prolonged high-speed effort. There are a few twists and turns in Lomopardo and Estella del Marqués, where there’s also a time check. The route is tailor-made for pure time trial specialists so look out for big performances from Küng and Hayter.
The course map
The course is pretty simple, there are around 10 corners that will cause the riders to have to take some kind of action, be that get off their aero bars or slam the anchors on, but in general it’s a flat TT that goes from one town to another – the kind we’ve seen a million times.
The wind map and surface friction
Anyone who’s ridden their bike in coastal European towns will be familiar with the wind. We’ve all left a town into the open areas and found ourselves suddenly being thrown around by the wind between hedgerows and buildings. That’s why we developed the surface friction mapping at myWindsock.
The myWindsock surface friction plot displays the area’s topology. Shaded areas are where the wind will move slower than forecasted due to buildings, trees or other physical features of the landscape. As it happens, for this particular time trial the wind is relative mild but we can still see areas of the course where buildings slow the wind down around the start and finish towns. The wind is forecasted to be around 5m/s (18kph) for the time around which the GC riders set off.
The race is forecasted to be majority tailwind which means that the windiest part of the day is actually the fastest.
As you can see, the wind adjusted elevation plot shows the course to be effectively net down hill, despite finishing at a higher altitude (slightly). Essentially, riding the course will feel “down hill” as riders are pushed along by the wind. Especially in the middle section between the two towns.
Riders will be setting off between roughly 2pm and 5pm for this time trial. Broadly speaking, conditions get slower throughout the afternoon giving the time trial specialists who are a long way down on GC even more of an advantage against the GC riders. The only GC rider who has a track record of beating the TT purists is Roglic, who will be setting off during the slowest part of the window.
There’s a ten second difference between setting off at 15:00 compared to 17:00, so there’s not a lot in it but we’ve seen world tour time trials of this distance won by smaller margins.
How hard is it to gain two minutes?
To have any chance of winning this Vuelta, Roglic will have to ride this TT about 2 minutes faster than Mas. Given this will be the target, how good a performance is actually needed to pick up two minutes on a “bad” time trialist?
A bad time trialist in the Vuelta is a pretty good time trialist:
Enric Mas will probably not mind us saying that, relative to other riders at his level, he’s never been the best time trialist. Reportedly, he weighs about 61kg and has a sustained 40 minute power of around 370W. Let’s say he’s about 4% lower power on the TT bike than the road bike (this is the upper end of “average”) then we can guess he will ride around 355W for this TT. We’ll assume his cda is 0.2, it’ll likely be a little lower but as he’s not a TT specialist he will also sit up a bit, so that’ll drag his average cda up slightly. We will assume his mechanics have him on fast tyres and a fast drive-train.
Plugging all of these assumptions into myWindsock gives Mas a predicted (but large error bars here as this estimate really was a bit of a guess for things like power and cda) of 40:29.
In order to challenge on GC, a top GC rider will need to produce a time of 38 minutes and 30 seconds. What kind of performance does this require? Let’s go back over some of our assumptions and put them into “peak TT Roglic” mode.
Back in the day, Roglic wasn’t just a ‘good for a GC guy’ time trialist, he was great. He’s reported to be at a weight of 65kg, which is a couple of kg heavier than Mas. During this Vuelta, he’s been climbing at a similar, but slightly slower, rate as Mas. Based on his track record though, we can estimate him to be slightly more aerodynamic as well as have a slightly lower power loss in the TT position.
We will assume his sustained 40 minute relative power is 1% lower than Mas at the moment, based on their climbing performances so far during this race. This gives him an estimated 390W to play with, but we’ll assume he loses only 2% of this relative to Mas in the TT bars instead of Enric’s 4% drop off. That means our estimated TT power for Roglic during this TT is 383W. We will also assume a cda of 0.19, we could be more aggressive with this estimate but he’s currently struggling from the impacts of a crash in training before the Vuelta started.
All of these assumptions lead to a time of 38:56, about a minute and a half faster than Mas.
Now, in order to get that two minute gap back, he will have to take some risks on pacing. Let’s now assume he’s magically slightly more aero at 0.18 and loses no power in the TT bars. This is essentially the best possible day that Roglic could conceivably have…
This would give Roglic just over 2 minutes back. He needs a generational day, but it’s within the bounds of possibility.
This blog scratches the surface of how World Tour Cycling Teams use myWindsock to prepare for time trials. If you want a detailed look at Stage 18 of the Vuelta – you can check out the forecast here.
myWindsock’s new version, surface, allows you to customise the information panel on the right hand side of the user interface. While, of course, your account comes pre-installed with a large array of pre built panels focussing on many aspects of cycling including weather, aerodynamics, terrain and more – each rider is different and this blog will focus on how to go about setting up your own panels.
Panel Basics
This is a screengrab of the right hand side of the screen on desktop with the Ironman 70.3 World Championships course pre loaded into myWindsock. By clicking the three dots on the right hand side you’re able to see a drop down menu which contains the panel you’re in, the ability to edit it and an option for panel library. Next to the three dots, there’s a a star, which allows you to input a text based description of what you want and myWindsock will automatically adjust the panel based on what you want.
The pre loaded Panel Library comes with six options…
Default – A broad overview of the course.
Performance Deep Dive – Focussing on effort and power delivery.
Wind Analysis – This is self explanatory.
Course and Terrain – Focusing on the elevation and physical aspects of the course.
Race Plan – A panel designed for race preparation
Aerodynamics and CdA – Focussed on aerodynamic analysis
Users are also able to update the pre loaded panels, as well as design their own from scratch. Today, we’ll focus on editing the Race Plan panel to go from the default panel to one more focussed on triathlon.
Editing a Panel
There are two ways to edit a panel, the option from the drop down menu or the text input option.
The data panel can be customised with a prompt.
In order to decide what to prompt the panel we need to decide what we want to know in order to prepare for the race. Preparing for a triathlon is a unique challenge as we need to carry a lot, it’s not actually a maximal effort and we need to get the gearing correct. It’s also, in the case of professional racing, a “semi drafting” race where some advantage is to be gained by being among a group of riders even if they must stay 20m apart. This means that energy investment is less linear than during a pure time trial as energy applied at seemingly non optimal points in the course might actually make sense in the context of non-draft triathlon.
We can use the Panel Index to see what’s currently contained in the Race Plan. With this, we can see what’s currently contained in the plan and decide what we want to delete or add. The first thing we’ll do is prompt the text box to delete the “W’ Balance Risk” plot as I don’t have up to date critical power information for this race – just a rough idea of the power I could hold, so we’ll delete this as it provides a false precision for the pacing plan in my specific case.
We can ask myWindsock to delete the panel for us in natural language like this. The new panel index now contains four charts.
How many charts is too many?
For a course that’s 90km with mountains, it’s possible to summarise all the pacing and race preparation information between 5 and 10 charts. The exact charts you feel you need prepared is left for the user.
The first thing we will do is add two charts, one which has an elevation profile and a second which shows us the distribution of gradients during the ride.
Our new Panel Index looks like this. We can now go onto looking at the Pacing Strategy Section.
The interval sessions that appear in your training plan are sometimes in significant disagreement with the terrain around you. This can make route planning extremely difficult. The demands of races dictate your training sessions, but the demands of your training sessions can dictate your route. This blog will take you through how a training session can be planned using myWindsock.
The session we will plan today is a roughly 2.5 hour ride in Andorra with 12 x 3 minutes low cadence intervals with 1 minute between them. This means the climb needs to be long enough to do the whole block, steep enough to tolerate low cadence training but shallow enough that the rest in between is easy enough at a normal cadence.
Before the 12 x 3 minutes we have a warm up including 4 x 12s sprints with 48s rest and after the 12 x 3 minutes we have a 1 hour block of “zone 2” – so we’ll need a pretty much continuous up hill for that too.
This is the session structure. But the tricky thing is the start point for the ride is at 1800m, so we need to get down low enough to start while still doing some warm up sprints (not downhill). As such, we’ll break the ride up into 3 points, warm up (20 minutes), 3 minute efforts (48 minutes) and zone 2 (60 minutes).
The warm up
The goal is to get down as low as possible between 20 and 30 minutes while finding a small climb to do the warm up sprints on. The warm up starts with 15 minutes easy pedalling, and the road down hill is quite easy to pedal the whole way down as it’s pretty straight and pretty wide, so we’ll pop that into myWindsock and see how far we can get in 15 minutes…
15 minutes of easy pedalling gets us here, almost to the entrance of the tunnel which is flat and a safe enough place to do the warm up sprints as there’s a nice wide bike path through it and, luckily, I don’t sprint very fast. One advantage of making the route with myWindsock is that it allows me to plan to go through the tunnel, whereas Strava’s route planning tool seems to think bikes aren’t allowed through it.
myWindsock is predicting that we’ll get out the tunnel and have our 5 minutes post sprints recovery in just under 30 minutes.
By clicking the timeline at the bottom of the screen, we can add intervals. Adding in the sprints and recovery reduces our time estimate to the bottom of the climb to around 28 minutes.
3 minute efforts
The bottom of the longer climbs the other side of the tunnel start at around 1200m above sea level. The intervals total 48 minutes and during this our rider will climb at a rate of 1100m/hour so we need to gain around 900m for the duration of the intervals.
myWindsock is now estimating that we’ll get to the turnaround point at 1:13 into the ride. Technically, the recovery after the intervals into the zone 2 is meant to be 5 minutes, but we’ll hit the descent and see how long it’ll take to get down.
The Zone 2
The pleasant way back is via the Col d’Ordino but this doesn’t take me an hour.
The myWindsock prediction has us getting to the bottom of Ordino at around 1:30 into the ride and we’ve got 60 minutes of zone 2 left to do. The zone 2 up hill will take up another 900m of elevation or so.
From Ordino town to the very top will take about 35 minutes and bring the total ride duration to just under 2 hours and 10. That means we need to descend down the other side and ride back up toward the starting point. We’ll be at the bottom of the descent two hours and 15 minutes into the ride with 25 minutes of up hill riding to go which conveniently will take me right to the front door of my favourite cafe.
The total elevation profile of the ride looks like this. Including descents the estimate is a total of 2:50 minutes which is a little longer than the planned session, but it’s a price worth paying to avoid going out and back.
After planning the route in myWindsock, I’m able to send it directly to my bike computer as the two are connected.
This coming weekend the RTTC National 10 Mile Championships are taking place on the O10/1 course near Doncaster in South Yorkshire. The women’s and junior races takes place on Saturday and the men’s race is on the Sunday. Both days the first rider is off at 10am and the riders will be on course until around 11:20 on the Saturday and 12:10 on the Sunday. The course is identical both days though the weather forecast varies slightly.
The course itself is a pretty simple out and back so the only real variation in pacing will come from wind and blow ups.
Both days are currently slated to be dry, temperate and relatively windless so our forecasts will focus mostly on which day is the fastest. We will set up the riders each day as the same, with a cda of 0.21, a system mass of 75kg and an average power of 300W then see how the time evolves across the start time of each day.
The forecast
This graph shows how the conditions evolve throughout the day. This graph shows the conditions relative to neutral weather. When the points are at -1, this means that the course is 1 second faster, 0 means the conditions are completely neutral and above zero is that many seconds slower.
There is a brief period on the Saturday where the wind makes the course marginally slower. On the Sunday, the conditions get marginally faster throughout the morning. That, alongside traffic picking up, means that conditions for the final rider should be slightly faster but barely noticeable.
The margins are tight, and both days are pretty fast. Due to the shortness of a 10 mile TT it’s not an unrealistic scenario that the podium could be split with just a handful of seconds. We should expect to see some pretty fast times though, with good conditions for racing forecast.
On Sunday the 16th of August the RTTC National 12 hour time trial championships will be held in Monmouthshire on the R12/16 course. The first riders roll out at 6:01 and will be on the gas for the following 12 hours, completing as many laps of the course as they can in that time.
12 hour TT courses can be a little harder to model performance on seeing as we don’t know exactly what laps the rider will do. Typically, this decision is made on the ground by the race director as to which part of the course riders use due to conditions on the road and other logistical considerations. Obviously, the part of the course with the big hill in it is most likely slower, so if riders spend more time on there than the flat bit, their modelled speed will be slower too.
The Weather
A 12 hour time trial is quite a bleak endeavour, even for the most enthusiastic riders there’s always at least one portion of the race that leaves you questioning why you entered. Nothing would accelerate that moment quite like the freezing cold and the rain, however conditions appear to be on the side of the participants this year.
myWindsock’s weather panel has precipitation at 0 throughout the event, with a patch of rain moving in at 8pm. If that comes early it could make the last hour quite unpleasant, but by that point in a 12 hour time trial, it’s all unpleasant anyway. On top of the precipitation, the wind forecast is low throughout most of the day but it also picks up a little in the last hour, though 5.8m/s is not a particularly high wind speed.
The Elevation Profile
One of the toughest things about a long time trial is the back breaking work of spending 12 hours in the TT bars. Every time you sit up, you lose a couple of metres from your result. Steeper hills and low wind speed sections can give riders the opportunity to sit up without paying a penalty.
Unfortunately for these riders, there’s limited opportunities to get out the saddle. Even though the elevation profile is rolling, it would appear that none of these climbs are particularly steep providing limited opportunities to sit up without losing time. On the other hand, this can help during a 12 hour TT as high torque efforts come with muscular damage that feels absolutely dreadful in the second half of the race. A practical take away for riders is they should sit up during the parts of the course they’re travelling their slowest on.
As you may have noticed from the graphs, myWindsock has a new look thanks to our surface platform, which is currently under development. One new feature of this is we can write extensions, which are small snippets of code in a “high level” language called Lua. A high level language is one that’s reasonably close to written english, making the syntax easily decipherable such that learning to write these extensions can be done by anyone curious enough to try.
An example of extensions
We can use these extensions to take a look at the average speed changes as a rider sits up more or less frequently. Setting up a time interval, we can see what happens to the average speed if our rider sits up for 60s at the following intervals (for an 80kg system mass with an “in position” cda of 0.23 riding at 240W)…
Every 3 hours: 40.1kph
Once an hour: 40.1kph
Every 30 minutes: 40.0kph
Every 10 minutes: 39.6kph
This is the cda plot of our extension, obviously the “real life” value will look absolutely nothing like this – the real world is not this neat. It does help us quantify the impact of a small thing like sitting up for 60s. The flexibility of myWindsock extensions allows riders to test the difference in speed of sitting up every 15 minutes for 30s against sitting up every half an hour for a minute – or some other such variations. Obviously, there’s an infinite number of possible variations you can try, many of which are specific to individual riders. This is why we built the ability for you to write your own extensions.
All of the CTT courses are available in myWindsock. You can check it out here.
UK Time Trial Events
