How much slower is +5Kg (11 lbs)

Due to a very serious spinal injury, myWindsock founder Ben, had 12 months without cycling. He returns to cycling 5Kg (11 lbs) heavier. How much slower can he expect to be? See the Instagram post below.

A bit more detail

We are all about real world riding, so we picked a very typical 25 mile course, on an average UK spring day. This course has some small ups and downs but would be categorised as flat. You can try the course yourself here, J4/8.

Our experiment was acrross 3 power ranges, 100, 200 and 300 Watts. Look at the chart below to see the differences between the powers. The differences are considerable. Remember, the time affect of a resistance compounds the slower you are moving. Less power, greater cost. No more, “I’m too slow for that upgrade” 😉

Often cyclists are surprised by how little time weight costs on a flat course. We are told lighter is always better and to upgrade to the lightest components. As you can see losing weight will have an affect on your speed, but we hope this will keep everything in perspective when making lifestyle and financial choices.

How to try your own experiments

The beauty of myWindsock is that all the variables are accounted for, Physics, Weather & Performance. This allows you to get real world test results in a virtual environment.

  1. Simply pick any route from your “Activities & Routes” menu.
  2. Set the date and time of your experiment for the most accurate cycling weather.
  3. Make changes to your Virtual Athlete profile.

Have a try yourself here.

Preparing for my time trial

Hello readers of the myWindsock blog, lately you’ll have noticed we’ve been a little quiet here. This is because we have been working on partner content with CTT and NoPinz but we are back today and I (Tom) have signed up for a TT this coming weekend! I thought it might be a good opportunity to do a mini series on how I will use myWindsock to get ready for this TT, predict my performance and plan my ride. 

The race is a road bike time trial – this means I’ll not be allowed a TT specific bike or helmet – as well as restrictions on the kind of wheels I can use. It’s a 15 mile time trial on the H15/10 near Maidenhead. 

Luckily, I’ve done a few road bike time trials so I have plenty of previous data to help me prepare.

Predicting the race duration

The first step is to figure out roughly how long the race is going to take me. For this, I’ll need a cda value to plug into myWindsock. Using a time trial I did in August last year on my road bike I can get a value for my cda which will be relatively accurate. The stats from the race are below…

I didn’t have a great day averaging a lower power than I wanted, but the race has come in handy as I can use it to hopefully have a better day in future! A good example of why getting out to race is rarely a bad shout! From this race we can use my live cda plot to predict performance at another TT.

This plot shows us how cda develops with time and generally there’s a couple of key takeaways from it… 

  1. My cda on descents doesn’t vary a huge amount, but does get slightly lower as I go down hill. 
  2. I sit up way too much on faster climbs – this is something to avoid in my coming race. 
  3. My flat cda is around .253, descent cda around .247 and climb cda around .270.

The second step is to figure out how much power I can do at my race. The previous race we used to calculate my cda wasn’t representative of my abilities at the moment but recently I’ve done a critical power test. The outcome of this test put my critical power at 360W bang on – this is the power I’ll aim to average during the course of my TT at first and make micro-adjustments based on predicted race duration.

Plugging these numbers gives me a time of 34:39, or a speed of 43.2km/h… Stay tuned for tomorrow’s blog on my power plan, with a weather impact of 4.5% predicted, he who rides the smartest in the wind will prevail! 

How will a ride feel?

Take a look at the below graphic for this week’s Manchester District 10 mile. If you subscribe to myWindsock Strava Activity emails you may have already seen a similar graphic for your own rides. If not, activate your emails here.

56.4% headwind isn’t good news! However it is only through viewing the Feels Like Elevation graph beneath that we begin to see what affect the wind will have on the course.

Relating the wind to it’s equivalent elevation gain is one of the ways we are helping to describe the weather for cyclists. Learn more about Feels Like Elevation.

So what does this tell us? Initially we see an easing of the course profile due to the tailwind start. Then, once the headwind begins, the road begins to feel harder than the traditional elevation profile would suggest.

Graphs like Feels Like Elevation can be found for any past activity and any future ride forecast. Simply select the route from you Activities & Routes menu to begin.

If you haven’t already signed up for myWindsock Weather & Analysis, start here.

How much time does a skinsuit save?

If you’re reading the myWindsock blog, or came across this from our friends over at NoPinz it’s likely you already know what a skinsuit is and you might even be sold on the virtues of their number pocket that saves you watts. If you attend a local time trial, it’s likely the pointy end of the field will be in a skinsuit and these days, most people wear one for all forms of racing. The uninitiated, or even those of you that only take part in the skinsuit wearing because everyone else does, might be left wondering why people wear these? Surely a jersey and shorts is more comfortable? It certainly makes using the bathroom a little easier. We know a skinsuit is faster, but how much difference will it really make on race day? 

With great partners like NoPinz, we are able to get a hold of some data that tells us how many watts a skinsuit saves a rider and this can be converted into a change in cda. That’s all fine and good – but still doesn’t mean much on race day. What we really want to know is how much time will this save us today, or on the day of our race? During his hour record attempt, GCN’s Ollie Bridgewood used a NoPinz skinsuit to save himself a whopping 20W. These numbers are seen across the board and a ten percent reduction in drag due to a well fitted skinsuit is commonly seen.

Here at myWindsock, we specialize in turning data into information giving you confidence on race morning. Cycling is an uncertain sport and anything that can reduce the noise in the information that drives your decision making is valuable. By making use of our physics engine, we can calculate how much time a skinsuit will save you on a particular course.

A worked example – the Perfs TT

For our simulation, we will use two runs of myWindsock on Sunday’s open time trial which is being held on the Portsdown Hill circuit. We have fixed the cda at 0.220 for the first run and, while keeping all other variables fixed, we will reduce the cda to 0.198 for the second run. This is roughly the proportion of savings a skinsuit will achieve – worth around the 20W that Ollie was able to save with his Flow skinsuit from NoPinz. For this, our test rider is pretty handy – being able to maintain 325W for the duration of the TT with a system weight (bike, rider and equipment) of 80kg.

Test run 1: cda = 0.220

Our rider is coming in at a shade under 39 minutes with an average speed of 41.1kph – not bad! Let’s improve his wardrobe choice slightly and pop him in a NoPinz skinsuit and drop that cda.

Test run 2: cda = 0.198

The savings are huge, more than a minute! This is just the skinsuit too, imagine the cumulative savings from pacing, optimised position and other equipment choices. Slower riders will also achieve greater time savings for the same proportional saving in aerodynamics. As we can see, a skinsuit is worth it.

If you want to see how the watt savings touted by brands turn into time savings on your local TT course, they’re all available in myWindsock pre-loaded. Just hit Activities & Routes, UK Time Trials, and then scroll until you find your open TT! Or simply go here UK Open & Club Time Trials. On top of this, you’ll be able to see what kind of power is required for whatever performance level you are targeting.

How much slower are Winter Time Trials?

To mark the first British Open time trial of the 2023 season, we were happy to help Cycling Time Trials, the British governing body for time trials, with a bit of data.

> Read the Cycling Time Trials article

> BS19 Ely & District myWindsock Forecast

What is the difference between Winter and Summer?

To find out the difference between Winter and Summer, we ran a simulation for every day of 2022. That’s 365 times around the Ely & District course! We ran the myWindsock simulations at 300 Watts, 80kg, 0.200 CdA. Here’s what we found.

Each orange dot is a simulated time based on weather conditions. Each day of 2022 represented.

You can see from the above graph the day to day the variability of times for the BS19 course due to the weather. Time range from 55 minutes in Winter Months to 53 minutes in the Summer.

Another thing to note is the seasonal day to day variability, that is the difference between two days of the same week or month. In the Winter we can see this is around 60 seconds, however times are a little more consistent in the Summer at around 30 seconds. Good job myWindsock give’s you the tools to measure the impact of the Weather.

> Find your Open and Club Time Weather and Analysis

We have more information about how weather impacts cycling speeds, here are some more articles.

Why do you ride slower in Winter: GCN Tech Show

Slow vs Fast Riders who suffers more in Winter Kit

Why do you ride faster when it’s warmer?

Why you are slow this Winter

A chat with Mark Beaumont

A few months back, Ben from myWindsock was out supporting (and providing valuable data) to Mark Beaumont on his successful attempt to break the North Coast 500 record. We managed to get hold of Mark to ask a few questions about the big day (and a bit).

For those of you that don’t know, Mark Beaumont broke the North Coast 500 record – he did this completing the route in a time of 28 hours and 35 minutes. The previous record was a touch over 29 hours and was held by Robbie Mitchell – a seriously talented ultra endurance cyclist with national titles to his name. Obviously, no record attempt like this stands a chance of being successful without some serious weather forecasting – which myWindsock happily provided to Mark. We had a couple of questions for Mark about the record attempt…

We asked Mark about how his state of mind was impacted by the forecasting from myWindsock. He told us, “I knew that the NC500 record would be seriously hard.  Robbie Mitchell was the national 24 hour TT champion when he set it and had relatively calm conditions.  With over 10,000 metres of climbing, very little wind cover and changeable conditions in the north of Scotland, I also know that weather would play a massive part in our success.” It was clear that Mark understood the huge difference conditions could make and that predicting them would be important in a successful ride. He went on to say that myWindsock, “gave me great peace of mind” and that he was glad his team had the tool at their disposal. He finished by saying that myWindsock, “felt like a secret weapon, an element of planning that wouldn’t have been taken into account in such detail when Robbie broke the record the year before.” 

Despite the record being a continuous 28 hour ride with more than ten thousand metres of elevation, aerodynamics make a huge difference. Mark’s average speed was a touch over 18 mph (around 29 kph). The upshot of this is that a time trial bike is much faster. With a record of this length, holding the aero position can be hard. We asked Mark about how he factored in ‘non optimal’ aero conditions due to cold and fatigue. He told us, “We went to the Catesby Tunnel and did aero testing on a road bike with rain jacket and road helmet, versus the time trial bike with skin suit and aero helmet.” Catesby Tunnel is a disused railway tunnel now used for aerodynamic testing. Being underground, myWindsock isn’t a great deal of use here but it allowed Mark to obtain valuable data for his attempt – numbers we were able to plug into our algorithms in order to forecast his attempt. The results of the testing at Catesby were fascinating. Mark went on to say, “The difference was absolutely massive when extrapolated over 516 miles.  So when my neck started to really hurt about 7 hours in, I knew the penalty from cracking and changing my setup, which focused me to stay low and on the TT bike.” As night drew in, it became very cold but there’s an aero penalty associated with cold air and putting on more layers. Mark discussed this, “ Even as it got cold overnight, not putting on the gilet and keeping as efficient as possible was front of mind.”

Obtaining aerodynamic data isn’t enough on its own. With a relatively accurate value for cda (which is rarely static) we can predict how Mark’s time forecast will change due to positional and clothing changes. Not just how many watts it’s costing him. This is where myWindsock can be valuable in attempts like this – turning data into information. 

A record like this is an extremely tough endeavour. We asked Mark about getting back on the bike after his successful attempt. He discussed his timeline for getting back on and feeling ‘normal’ on the bike. “I was back on the bike a few days later for some gentle spins and to aid recovery.  But it took a few weeks before I felt my energy levels were back and that I could ride with any decent power again.” The fact that it took weeks for one of the best ultra endurance riders in history to recover is testament to how hard this record is. Throughout this, Mark was keen to stress the importance of his team. They, combined with the data that they were able to utilise from myWindsock, were able to keep Mark informed. He went so far as to say he was “just the engine on the bike”. His team gives him all the information he needs during his attempts and myWindsock was extremely glad to be a part of this wonderful attempt!

If you want to add a dash of confidence to your sporting endeavours, weather it’s breaking the NC500 record or chasing Strava segments, click here.

Why bother with a premium account?

myWindsock has a free version that many of you reading this will have used or be users of. Our free version is pretty feature rich, so much so that you might wonder why you should bother with myWindsock premium. Many of you won’t need premium, with something like myWindsock (one of Cycling Weekly’s top 10 cycling apps of 2022) it’s always going to be an optional extra. At less than £2/month, it’s one of cycling’s cheaper optional extras though…

For a detailed account of why you should get premium and an in-depth description of the features, click here. For those of you still here, read on for three reasons you should consider upgrading to MWS premium.

Track weather trends

Climbing hills and riding long distances are all recorded, and both are feats to overcome. A myWindsock premium account will allow you to track weather trends over time too. You will know what your longest headwind is, how your cda changes from summer to winter as well as your wettest and coldest rides. 

If headwinds were hills

Hills are great because you can see them, quantify them and conquer them. Headwinds can be equally tough, yet the sense of satisfaction for ‘getting through’ a headwind isn’t quite there. Well, resistive forces are all the same in the sense that they can be turned into climbs. A headwind of a certain force for a certain duration is equivalent to climbing some given number of vertical meters at a given gradient and myWindsock calculates this for you. If you want to learn more about this, click here

Plan races like a pro

There’s a reason World Tour teams, ultra distance record holders and Olympic champions use myWindsock to plan their races – because they think it’s the best tool for the job. Who are we to disagree with them? With MWS Unlimited (£2.08/month) you can plan your races with limitless detail. 

For more detail on myWindsock Premium, as well as sign up links – click here

Critical Power

myWindsock uses W’ Balance to help you pace race efforts correctly. W’ Balance allows you to maximise the work done above critical power (CP), but what exactly is CP? 

What is CP?

Critical power is the idea that the power duration curve can be fit to an equation which is approximately true for all athletes. Obviously, it’s more true for some athletes than others (there are statistical anomalies in any population). The point at which this approximation is no longer true will be somewhere between 30-60 minutes where the curve will tend toward a straight line – this line is where your critical power sits. 

The area between this curve and the CP line is your W’ – this is the amount of energy you have available above your critical power. You can use it all in one go with a big sprint, or burn it slowly with extended time just above critical power. 

How do I test it? 

You can test your critical power by doing two power tests and fitting a curve to the results of these tests. High North have quite a neat CP calculator available on their website. The favoured duration amongst coaches seems to be 3 minutes and 12 minutes. If you’re a 10 mile time trial specialist you might wish to do a 20 minute test as this is closer to race duration. Having more data points will also mean your CP value is more accurate so doing 3 tests might be better.

The W’ Balance tool

A more detailed description of how this works can be found here but we shall briefly discuss the tool here.

You can see in the graph that time spent above Critical Power depletes W’ and this is why having an up to date CP value is important for pacing – you don’t want to risk blowing up before the end or finishing with lots in the tank. 

If you like pacing tools and racing with confidence, you can sign up to myWindsock here! If you want a more detailed explanation of Critical Power, or any other metric on myWindsock get in touch with us via our social media.

Why are winter time trials so much slower?

It’s January which means one thing only – TT season is round the corner (ok maybe it also means other things). Races are popping up from mid February which means some early season form testing is on the cards. You might find that, as a result of a really consistent winter, your power numbers are really good this time of year yet you churn out a couple of slow time trials before it warms up. New kit, new bike fit, more watts and still going slower, but why? Winter time trials are slow!

Rest assured, it’s probably nothing to do with how powerful or inherently aero you actually are yourself and is more to do with the conditions. Of course, by subscribing to myWindsock you will have confidence in knowing this as the conditions are taken into account and you’ll know it was a slow day with high Weather Impact.

Cold is slow!

The speed you ride at for a given power on a given day with some given cda is proportional to one over the square root of the density of the air that you’re riding through. This basically means that as air density goes up, our speed will go down. Air density is impacted primarily by temperature. Hot molecules move faster and spread out more. This means more air occupies some given space when it’s cold compared to when it’s hot. In a time trial, the amount of space we need to pass through is fixed at the distance of the race, but the amount of air occupying this space varies quite a lot from one day to the next. 

If you have left your house at any point since October, you might have noticed it’s become rather chilly. As time trialists, we think “gosh, the air is rather dense today” and people look at us like we have just started speaking Spanish. Cold days are slow days. It’s just the laws of physics. 

If it’s slow, what’s the point of racing in February? 

Time trialing is part art, part science. The ratio of art to science will vary depending on who you ask but everyone agrees, to get good at time trials you have to do them. As with anything though, blind practice only gets you so far. Practising with purpose is the key. 

What would be handy is some kind of service which analyses your winter time trials and tells you how much impact the weather would have and how aero you are. Of course, you can see all of that information here. 

Use myWindsock to dial in your pacing and kit choices so that by the time summer comes around you’re dropping massive PB performances with confidence.