Rider weight and windy days
 

Sup guys, today I was chatting with this girl I came across while riding, and the subject of wind came up. The wind on a certain road I brought up annoyed her, and I postulated that heavier/bigger riders might fare better in the wind. Smaller riders are better on hills of course, so it would be interesting/cool if bigger riders did better in the wind. Im 265 lbs and haven't really been bothered by crosswinds, but I have a larger frontal area which is bad in the wind. I also have more momentum than a smaller rider, I don't know if that matters much. I bet heavy people are good in crosswinds, but are we better in headwinds as well? Heavier guys can put out more power so wind might be a less relative effect as well.

Have people looked into this?

I'm medium weight, but once or twice a week I eat tacos for dinner and I consider it training for blustery days. :)

See, these are the kinds of tough questions that I'd expect from someone that regularly touts their academic training and scientific work environment.

Yup. That's why I have more power than Froome.

I dropped out of college 3 times and never finished :( should have done some silly degree I was trying for chemistry. Wanted to mass produce LSD. If this is such a simple question then what's the answer?

Get along, Kid Charlemagne.

The thing about being larger is that your increased mass and ability to put out power is a greater factor than the increased frontal area in the wind. That's why TT specialists are not little wispy guys like the pure climbers.

Regarding susceptibility to crosswinds, I suspect heavier riders may have an advantage but a LOT of it is the bike itself and your balance on it. Among my bikes there are some that seem to ignore crosswinds and some that are easily pushed around by them. I find my metal bikes tend to be less susceptible, whereas the most susceptible is a CF Bianchi from 2006 which presents some flat surfaces to crosswinds. But I seem to have reduced that by moving my position slightly up and forward, so that there's more weight on the bars. I've found when hit by crosswinds, the normal reaction is to sit up a bit , which unweights the front a bit. If I put weight back on the front, it seems to stabilize the bike.

Here in the 4th windiest city in Canada, and home to the windiest intersection in the land, plus being tall & presenting a wide cross section to frontal wind I can say with complete certainty wind is a significant impediment. The bike also weighs 44 lbs dry. The wind is always your companion here.

Regardless of any perceived benefit. I'd rather be a light rider with a high watts/kg and just take my chances with any wind if there are indeed chances to take.

I think wind is going to have more affect based on aerodynamics….than rider weight. I hate wind…but I’m much stronger now(and I slammed my stem)….and wind doesn’t have nearly the affect on my rides as it used to

If you are physically stronger in terms of W/kg than someone else, you will be able to punch a hole through wind more easily. Larger riders tend to have greater muscle mass and if they are in good shape, tend to have greater W/kg. The difference between a larger rider in good shape vs lighter rider in good shape is not very much in an aero position. Advantage larger in-shape riders against the wind.

An overweight blob will present a greater surface area to the wind and have lower W/kg despite a large muscle mass - because lots of useless fat mass too. Advantage lighter riders.

There are anomalies, exceptions. If you are small, light, taking full advantage of being a little bit more aero, and have a high W/kg, let the big guys punch the holes and then sprint past them in the final 200m. :) Or if you are Wout van Aert who is a large, super-human monster and can do everything from climbing, to sprinting to TT's.

Personally, I'm small, light and have enough watts to power past a lot of big guys, especially if it is an incline where their weight counts against them more. But in a windy time trial situation, yeah, those big guys tend to have me beat. Unless longer uphills, where my need for less energy than them helps me.


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It's a lot harder if you wear parachute pants.

Why, Why Why? Ever hear of the metric W/CdA?

Froome would agree heavier riders have an easier time in wind.

Because, because, because this is the real World and not hypothetical physics in a perfect environment! Note what I wrote - I did not suggest that there was no difference, I wrote that there would be a small difference. This is generally true.

W/Cda is relatively small between a larger cyclist and a smaller cyclist when both are presenting a good aero position on the bike, certainly not enough to overcome the W/kg advantage. A large, overweight person who cannot adopt an efficient W/Cda will, of course, be inefficient.

This is one of the many reasons that Ganna et al dominate flat TT's vs noticeably smaller riders, few freakish exceptions aside (think Remco), from time to time. Lighter riders take over when gradient counts against the heavier riders but we're talking flat.

Obviously, there are other variables too - it isn't just about W/kg, W/Cda etc. But for the sake of this basic discussion and not going crazily in-depth, the above is generally the case.


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Not what I was responding to, but thanks for trying.

I thought you're supposed to ride a cross bike to reduce the effects of windy conditions. Or not.

:rolleyes:

No, no one has ever considered the effect of wind on cyclists.

Watts/kgs matters on climbs but is not relevant to this discussion, on a flat road in windy conditions its about power and wind resistance.

Really? What do think power is then?

Taking a 175lb rider pushing 300W with a W/kg of 3.75 and a 145lb rider pushing 300W with a W/kg of 4.60 as a baseline to start my thought process on this...

In this scenario where both are pushing the exact same Watts, the lighter rider has the clear advantage in terms of both Watts and, most often, Cda. If you do a Cda calculation on both, then the smaller rider will likely have aero gains, sure.

But you and another chap want to ignore W/kg to make the above true in all cases and focus only upon CDa. I'm not convinced because what happens when a rider has significantly more W/kg than another? Does CDa still win out overall? Or do the W/kg come into it? I think the W/kg come into it.

An excellent CDa is .19 - anything below .20 is fantastic. Larger riders do tend to have higher CDa's naturally than smaller riders, this is true. However, we have big units getting down to .20/.25 in the World Tour peloton and so pretty much negating the aero advantage of the smaller riders in a time trial position; hence large units like Ganna, Bisegger, Dowsett etc being so good.

Assuming both of my above examples are adopting a very good time-trialling aero position achieving a Cda of around .25 and .20 respectively to take into account an advantage for the smaller rider and pushing the same watts, yes the smaller rider has gains and wins - he/she will be able to push through the wind faster.

Now...if the larger rider is stronger as is most often the case at higher levels of the sport and has way more mitochondria in his bigger legs...

The 175lbs rider is now pushing 5 W/kg and still assuming a very good CDa of .25 and .20 for the smaller rider at 4.6 W/kg because they both have the best equipment and their coaches have them dialled in for position, the larger rider wins. W/kg trumps the CDa advantage.

There are other variables too. It isn't as clean cut as this in all cases - larger riders can still have lower CDa's than smaller riders depending upon physique. It does happen. But generally, we assume smaller riders have a better CDa albeit, as noted, this is not always the case. But they can be out-powered by the big units who have a greater W/kg. And then there are smaller guys with big W/kg, more than many larger guys, like Remco...so it's not straight-forward.

All that said! What happens in a sprint? Well, this is somewhat different to the very aero positioning of a time-triallist since now we are talking about standing up on the pedals...this is where the likes of Cavendish and Ewan can compete against the huge W/kg and max power that the larger units can achieve precisely because of a lower CDa. Larger guys stomping on the pedals struggle to achieve Cav's ultra-aero sprint style. Not all smaller riders are as good at this - Cav has a really aero sprint that he has perfected and larger guys would not be able to match it. Of course, Cav still needs plenty of watts too but can get away with less if he times it just right because for a short period, the big guys have to work a lot harder than he does.

The above outdoors in a typical road race, not indoors in a Velodrome where absolute power is what is required.

So yeah, aero and CDa is extremely important in cycling but so is W/kg and a host of other stuff too. While these two can make big differences, it is the sum of a total of many things that lead to the faster rider in all conditions.

I've focussed upon Elite athletes, at normal levels of the sport the variables are vast and so differences can be much greater. For example, larger riders can more easily have really bad CDa's and then smaller riders can push through wind far easier, if that's what you want to hear. Dialled in, strong big units can reverse that though. :)


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What I read from many highly experienced riders in BF based on their group ride experience:

- The difference in absolute power output between heavy and light rider is greater than the difference between their CDa.

- Absolute power (not w/kg) matters more in the flats.

- Their experience confirms that the higher w/kg of light riders (with their higher speed on the climbs) isn't an advantage on the flats if the heavy rider has significantly higher power output even if their w/kg is less than the light riders.

- Many instances of light riders with higher w/kg struggling to keep up with heavy riders on the flats while having the opposite result on climbs with the same group on the same ride.

- All this proves the difference in CDa between a heavy rider and light rider is not as big as the difference in absolute power output, all things made equal like physical fitness, training, equipment, fueling, etc.. This gives the advantage to heavy riders on the flats

- In relevance to this thread, heavy riders will have the advantage in windy conditions including headwind and also riding in the flats if they have the same physical fitness as another rider who is light.

If you read what I wrote in my two posts here I have written very similar re the impact of CDa and advantages of the larger rider due to being stronger; I am suggesting that larger riders typically have the advantage on the flats which is exactly what you are concluding too, despite Cda. The only difference is how we get there and that I don't say that as a firm rule since there are many exceptions due to other variables.

You see, it is, as I also wrote, not as straight-forward as the large guy with more absolute power always goes fastest on the flats. I drop riders literally twice my size on group rides and in races - on the flat. They are physically stronger than me. They are as fit as me.

So why does that happen because it blows apart the theory that on the flat and into the wind, heavier riders have greater absolute power that trumps all?

The answer is, as I wrote, albeit only in my own humble opinion and experience, the sum of many factors and W/kg and CDa are two of them. Not just absolute power. I am getting old now but I can still hold 16W/kg for 10s and my 1min, 2min and 5min watts are relatively higher than some much larger, stronger guys who have more in terms of absolute power and greater peak power but who can't sustain it.

I'm smaller, lighter but often with more power to weight to call upon despite not having the absolute bigger numbers of many.

Look at Wout van Aert. Possibly the best all-round cyclist in the World today. A large man, 172lbs of muscle, who can win time trials on the flat, who can win undulating endurance road races, who can win steep mountain races and who can win sprints - all against riders who specialise in each of those at the very highest level. He can do it all.

Then look at Remco Evenepoel. Tiny in comparison. He's smaller than me! 134lbs. And yet he is also a time trial specialist at the highest level who can give WvA a run for his money and has beaten him. Earlier this year he won the Volta ao Algarve and the final TT - in 50km/h headwinds - 31mph! He just won San Sebastian for the 2nd time, with a 44km solo breakaway. The lad is small! Held off a peloton of big units. It was not all down to a better CDa, it was not down to absolute power, it was not down to W/kg. It was a combination along with other variables.

While we all seem to be suggesting larger riders often have an advantage due to increased muscle mass that can overcome a smaller riders better CDa where it exists, I don't subscribe to any rule that this means larger riders will always be better into a wind and I don't believe any one criteria like absolute power alone dictates an obvious win. It's the sum of many factors but there will always be exceptions to what appears obvious since those variables shift the dynamic quickly - at all levels, not just Elite.


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Thinking about the girl I rode with two days ago, she was 105 lbs. She certainly has a higher w/kgs than me and would beat me up a hill, but that doesn't matter for the flats. I have more raw power and and eat more wind with a larger CDA (just learning this term) and would win on a windy flat road putting out substantially fewer watts/kg.

And yet, no disrespect, I'm 141lbs and would drop you from my wheel relatively easily even on a pancake flat road. I'm not trying to be funny here, it's just that absolute power isn't what you think it is as a winner takes all. You describe yourself as a heavy unit and for sure you are most likely stronger than me but that doesn't mean you will take me on a flat road. Read my post above for why.

Speaking of women. I had the privilege to train with one of the ladies from the WorldTour peloton earlier this year from Human Powered Health. She destroyed me on the climbs, as expected but guess what? This woman, lighter than me, same height as me, was super-difficult to keep up with on the flat on her wheel and could drop me. In a sprint, I had the advantage but that was the only card I could play, she beat me comfortably in every other way.

It is true that we can indeed suggest that heavier physically stronger riders have an innate advantage on flat roads, just as smaller riders have one with CDa, but both can have those advantages rubbed out by other factors. For example, W/kg works for all types of riders, not just light ones - don't assume it is only the lighter mountain goats who need to concern themselves with it. Big units can have mountain-goat catching W/kg too! Absolute power/power-to-weight/W/kg/W/CDa...you need it all.


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But heavier riders are at a distinct disadvantage, because VO2max is negatively correlated to body mass -- even when looking at lean body mass.

Generally, absolute power increases with lean body mass, but not as rapidly as VO2max (and thus power-to-weight ratio) decreases with lean body mass.

Yes, there are exceptions. There are always a few who win the genetic lottery and fall outside the norms.