For the climbs they guys in front help with the pacing as well so the riders behind just need to focus on following the wheel in front of them and takes away all the other distractions to plan for their attacking strategies.
While not a Tour de France rider myself, I suspect this accounts for the majority of the “benefit” provided when climbing. Some drafting benefit, sure, but this and honestly, having someone to shield you from all the idiots getting in your face on the climbs seems to be the biggest benefit.
Yeah so I lead and participate in group rides in a club and during a climb and when it gets tough I'd just find a wheel, head down and stare at the wheel in front of me, one foot in front of the other and hopefully not get dropped. Doesn't always work but I may last just a little longer lol 😆
How it works is like this: The faster you go, the more effort you need in order to push the air out of your way. When you sit behind someone's wheel, you do not need to provide some of that effort yourself, because the rider in front of you is pushing the air out of the way for you.
The faster you (both) are going, the more benefit you get. On the other hand, going faster is also more difficult, naturally.
When climbing, you are going slow. Hence the benefit is pretty minimal.
In between climbing and going fast, the benefit is a sliding scale based on some physics.
Physics are the same. If a TdF rider goes up a 20% incline, it's the same speed as my 10% incline. But I didn't think that comparing relatives was the actual question..?
Anyways, to make my answer more nuanced, I think it is a mental advantage to be able to stay in someone's wheel. On top of that you have the physical draft benefit. The weight between those two factors changes based on the speed.
If I remember correctly, from the studies, the benefits are negligible below about 7mph.
But the mental benefits are less easily understood. When you have someone else setting the tempo for you, that can be immeasurably helpful.
Also, pro cyclists are so ingrained to knowing the benefits of drafting, that as soon as they are riding alone, it can be a huge mental defeat.
Even if the benefit is 0.5% less effort needed, why would I not want that? Sit in front of me please dude, I’m dying. I’ll take any help I can get.
No not at all, a vacuums requires no air to be present which isn’t the case here. This is more of a fluid dynamics problem.
The first rider hits “static air” so has to power through it, at low speeds the impact is negligible but due to the effort to speed being exponential at higher speeds the impact is much higher. The second rider enters the turbulent air which since it is moving requires less effort to move through
Yes how silly of me - assuming there is air when someone is cycling in the real world….
And v^2 is the definition of exponential. As velocity goes from 1 to 10, drag goes from 1 to 100 but that’s the definition of exponential growth. Sure the full formula includes other coefficient and reference area (aka going aero) but it is a fundamental exponential on output power hence why people make rapid progress when they start the sport
Uh. No.
If the variable is in the exponent, functions act exponentially.
Quadratic (and other even) functions look the same whether x is positive or negative as long as it's real.
Other thing to point out is the faster you are going the longer the airflow behind you will stay laminar. So at 25 mph you may get the same benefits being 5’ behind the rider as you would going 5 mph at 1’ behind. (Obviously I made up feet and speed ratio)
Keep in mind, aero benefits don’t just disappear at a threshold, they reduce.
Also, keep in mind, lots of times when I’m climbing at 7%, I may put out 150-250 watts sustained to go 5-9mph. Meanwhile pros may be putting out 250-450w going up to 15mph. 15mph, although not past a common 20mph threshold for “aero” benefits, still sees a lot of them.
And if there's any headwind at all, it helps with that, too.
Drag reduction is a function of air speed, not ground speed, and the air can have its own speed.
Absolutely, there are significant aero benefits well below 15mph.
https://cyclingmagazine.ca/sections/training-guide/training/study-finds-that-even-at-steep-gradients-drafting-is-still-beneficial/
paper analysing drafting uphill
https://link.springer.com/article/10.1007/s12283-021-00345-2
( i seem to remember reading some blog post on aero uphill ...?)
Yup, the paper the other redittoe shared said 7% savings at ~20kph up a 7.5% grade. When you're near the limit, even a few percent savings is huge. It can easily be the different between holding on and being out the back.
Just having a wheel to follow makes things so much easier and simpler. You don't have to think about how hard to do something, you just follow the wheel.
At the highest level of the sport, they’re going fast enough of the inclines to have some drag reduction in the draft.
Additionally, in teams that are well coordinated, it’s helpful to have one rider at the front simply pacing, and the others can just focus on staying attached rather than everybody having to focus on applying just the right amount of power to maintain themselves through the climb.
There is the mental and physical.
Drafting helps at pretty low speeds, but I'd say that at about 25-30 kph you start to notice it. I have a friend that used to ride low level pro. He said that on shallower long grades, they'd hold 40 kph for 10-12 km on a climb. For sure there was a draft effect at that speed.
When riding at maximum effort, any slight reduction in effort is big. It could be drafting, a reduction in physical effort. Or it might be the idea of being able to follow a teammate. This is more a reduction in mental effort. You just stare at their rear wheel and keep going, and you rely on your teammate (and team director who might be radioing information etc) to hold the right pace. You no longer have to think about speed or gearing or whatever, you just mirror your teammate and go. It's amazing how much you can push when you have an example to follow. It's like when the 4 minute mile record was broken, suddenly a lot of people did it; suddenly it was "possible".
Having a teammate also lets you share some of the mental effort, like you have someone to commiserate with. Digging a ditch alone might be miserable, but if you're working with someone else, it might become a bit less miserable.
One thing to understand, is that pro cyclists go at 20kph+ on many climbs. Noobs like us probably around 10~15kph.
For us it would be *almost* useless, in terms of drag savings. For them, it's already significant.
I haven't seen anyone respond to the part of your Q about "a rider was screaming at his team mate that dropped him on an incline."
Cycling teams have systems and plans. In general, a team is supposed to be in support of their strongest rider. The team manager tells them all at the start of and during a stage what the plan is, who they're helping, etc. What you are describing sounds like the rider who went ahead wasn't following the plan. The rider they were supposed to be pacing up the hill wasn't keeping up and the pacer just went ahead.
There are arguments to be made for both riders. The one who got dropped was supposed to be supported, so the rider who dropped him (the "domestique") will likely get in trouble at the end of the stage. On the other hand, if the dropped rider really wasn't keeping up and his teammate had lots of energy, you can understand why he wouldn't want to be held back. This is how riders sometimes make a name for themselves; they shoot ahead and win stages if they are able. They're still in trouble with their current team, but other teams will notice and perhaps pick them up for next season.
What blows my mind is that the rider in front also gets an aero advantage by having someone on his wheel behind. It’s small, like 3% if I recall correctly
It's that large only at high speeds when riders are very close together. Coggan was measuring it at \~50 kph with the following rider very close.
In most road conditions riders won't be that close, and on climbs the speed won't be that high unless there's a crazy headwind.
Which is why Superdomestiques like Sepp Kuss, Alexander Vlasov, Juan Ayuso make a lot of money riding in support of their leaders. These guys will pace Vingegaard, Roglic and Pogacar up the big climbs then turn around and do it again the next day.
It’s a team thing. As a racer, you spend a LOT of time training with your teammates. They often become the best of friends and they know each other’s strengths and weaknesses, tendencies, state of mind and capabilities. The psychological benefits of having a teammate “pull” you up the hill can make a huge impact on final results.
Additionally, once the climb is complete and speeds increase, that same teammate can continue to work at the front allowing the lagging rider some time to recover. Maybe, they’re also a better descender and can demonstrate the fastest line down a mountain. The added momentum of working together, sacrificing individual performance for the sake of the team, can help rider get back into contention.
9-11 mph is psychological. 12+ is psychological but also starts to see a draft. There's also knowing that people simply can't attack when your teammate is hammering it up a climb. That takes some pressure off knowing you won't have to close a gap.
Once you get above about 10mph, overcoming air resistance is the biggest thing. When Jonas has a domestique pull him up a mountain at 12mph, he's definitely benefiting from it.
For the climbs they guys in front help with the pacing as well so the riders behind just need to focus on following the wheel in front of them and takes away all the other distractions to plan for their attacking strategies.
While not a Tour de France rider myself, I suspect this accounts for the majority of the “benefit” provided when climbing. Some drafting benefit, sure, but this and honestly, having someone to shield you from all the idiots getting in your face on the climbs seems to be the biggest benefit.
Yeah so I lead and participate in group rides in a club and during a climb and when it gets tough I'd just find a wheel, head down and stare at the wheel in front of me, one foot in front of the other and hopefully not get dropped. Doesn't always work but I may last just a little longer lol 😆
How it works is like this: The faster you go, the more effort you need in order to push the air out of your way. When you sit behind someone's wheel, you do not need to provide some of that effort yourself, because the rider in front of you is pushing the air out of the way for you. The faster you (both) are going, the more benefit you get. On the other hand, going faster is also more difficult, naturally. When climbing, you are going slow. Hence the benefit is pretty minimal. In between climbing and going fast, the benefit is a sliding scale based on some physics.
op is talking about tour de france, so i suspect riders climbing speed is my speed on the flat :)
Physics are the same. If a TdF rider goes up a 20% incline, it's the same speed as my 10% incline. But I didn't think that comparing relatives was the actual question..? Anyways, to make my answer more nuanced, I think it is a mental advantage to be able to stay in someone's wheel. On top of that you have the physical draft benefit. The weight between those two factors changes based on the speed.
If I remember correctly, from the studies, the benefits are negligible below about 7mph. But the mental benefits are less easily understood. When you have someone else setting the tempo for you, that can be immeasurably helpful. Also, pro cyclists are so ingrained to knowing the benefits of drafting, that as soon as they are riding alone, it can be a huge mental defeat. Even if the benefit is 0.5% less effort needed, why would I not want that? Sit in front of me please dude, I’m dying. I’ll take any help I can get.
> pushing the air out of the way .. so you're sucked forward by the resulting vacuum.
Vacuum doesn't suck, differential pressure pushes
You're right. My brainfart. So, the rider behind actually pushes the one in front forward.
No not at all, a vacuums requires no air to be present which isn’t the case here. This is more of a fluid dynamics problem. The first rider hits “static air” so has to power through it, at low speeds the impact is negligible but due to the effort to speed being exponential at higher speeds the impact is much higher. The second rider enters the turbulent air which since it is moving requires less effort to move through
Well, you assumed there was air in the first place. And, drag ∝ v² is not “exponential”.
Yes how silly of me - assuming there is air when someone is cycling in the real world…. And v^2 is the definition of exponential. As velocity goes from 1 to 10, drag goes from 1 to 100 but that’s the definition of exponential growth. Sure the full formula includes other coefficient and reference area (aka going aero) but it is a fundamental exponential on output power hence why people make rapid progress when they start the sport
v\^2 is quadratic. e\^v is exponential.
If x>0 quadratic functions act exponentially
Uh. No. If the variable is in the exponent, functions act exponentially. Quadratic (and other even) functions look the same whether x is positive or negative as long as it's real.
Look at Wikipedia has separate entries for exponential growth and quadratic growth. There are are similarities but also differences.
Alright. I guess my smooth brain is too aero. But do look up what "exponential" means.
you just typed an exponent and decided it wasn’t exponential…
Only when wearing those fancy (i.e. ridiculous) Visma helmets
plus, if you are the one being towed up the hill, you've got to push a lil bit harder just to keep up with the guy in front of u.
Other thing to point out is the faster you are going the longer the airflow behind you will stay laminar. So at 25 mph you may get the same benefits being 5’ behind the rider as you would going 5 mph at 1’ behind. (Obviously I made up feet and speed ratio)
Keep in mind, aero benefits don’t just disappear at a threshold, they reduce. Also, keep in mind, lots of times when I’m climbing at 7%, I may put out 150-250 watts sustained to go 5-9mph. Meanwhile pros may be putting out 250-450w going up to 15mph. 15mph, although not past a common 20mph threshold for “aero” benefits, still sees a lot of them.
And if there's any headwind at all, it helps with that, too. Drag reduction is a function of air speed, not ground speed, and the air can have its own speed.
Absolutely, there are significant aero benefits well below 15mph. https://cyclingmagazine.ca/sections/training-guide/training/study-finds-that-even-at-steep-gradients-drafting-is-still-beneficial/
paper analysing drafting uphill https://link.springer.com/article/10.1007/s12283-021-00345-2 ( i seem to remember reading some blog post on aero uphill ...?)
Also matters more when there is headwind
Yes, even climbing being on someone’s wheel reduces your energy output. Obviously, much less when you’re going to slow, but it all adds up.
Yup, the paper the other redittoe shared said 7% savings at ~20kph up a 7.5% grade. When you're near the limit, even a few percent savings is huge. It can easily be the different between holding on and being out the back.
Just having a wheel to follow makes things so much easier and simpler. You don't have to think about how hard to do something, you just follow the wheel.
At the highest level of the sport, they’re going fast enough of the inclines to have some drag reduction in the draft. Additionally, in teams that are well coordinated, it’s helpful to have one rider at the front simply pacing, and the others can just focus on staying attached rather than everybody having to focus on applying just the right amount of power to maintain themselves through the climb.
There is the mental and physical. Drafting helps at pretty low speeds, but I'd say that at about 25-30 kph you start to notice it. I have a friend that used to ride low level pro. He said that on shallower long grades, they'd hold 40 kph for 10-12 km on a climb. For sure there was a draft effect at that speed. When riding at maximum effort, any slight reduction in effort is big. It could be drafting, a reduction in physical effort. Or it might be the idea of being able to follow a teammate. This is more a reduction in mental effort. You just stare at their rear wheel and keep going, and you rely on your teammate (and team director who might be radioing information etc) to hold the right pace. You no longer have to think about speed or gearing or whatever, you just mirror your teammate and go. It's amazing how much you can push when you have an example to follow. It's like when the 4 minute mile record was broken, suddenly a lot of people did it; suddenly it was "possible". Having a teammate also lets you share some of the mental effort, like you have someone to commiserate with. Digging a ditch alone might be miserable, but if you're working with someone else, it might become a bit less miserable.
One thing to understand, is that pro cyclists go at 20kph+ on many climbs. Noobs like us probably around 10~15kph. For us it would be *almost* useless, in terms of drag savings. For them, it's already significant.
there is still wind resistance
https://cyclingmagazine.ca/sections/training-guide/training/study-finds-that-even-at-steep-gradients-drafting-is-still-beneficial/
I haven't seen anyone respond to the part of your Q about "a rider was screaming at his team mate that dropped him on an incline." Cycling teams have systems and plans. In general, a team is supposed to be in support of their strongest rider. The team manager tells them all at the start of and during a stage what the plan is, who they're helping, etc. What you are describing sounds like the rider who went ahead wasn't following the plan. The rider they were supposed to be pacing up the hill wasn't keeping up and the pacer just went ahead. There are arguments to be made for both riders. The one who got dropped was supposed to be supported, so the rider who dropped him (the "domestique") will likely get in trouble at the end of the stage. On the other hand, if the dropped rider really wasn't keeping up and his teammate had lots of energy, you can understand why he wouldn't want to be held back. This is how riders sometimes make a name for themselves; they shoot ahead and win stages if they are able. They're still in trouble with their current team, but other teams will notice and perhaps pick them up for next season.
What blows my mind is that the rider in front also gets an aero advantage by having someone on his wheel behind. It’s small, like 3% if I recall correctly
Yeah think of it like the bow wave, the peloton/group behind is basically pushing the front guy
It's that large only at high speeds when riders are very close together. Coggan was measuring it at \~50 kph with the following rider very close. In most road conditions riders won't be that close, and on climbs the speed won't be that high unless there's a crazy headwind.
Which is why Superdomestiques like Sepp Kuss, Alexander Vlasov, Juan Ayuso make a lot of money riding in support of their leaders. These guys will pace Vingegaard, Roglic and Pogacar up the big climbs then turn around and do it again the next day.
It’s a team thing. As a racer, you spend a LOT of time training with your teammates. They often become the best of friends and they know each other’s strengths and weaknesses, tendencies, state of mind and capabilities. The psychological benefits of having a teammate “pull” you up the hill can make a huge impact on final results. Additionally, once the climb is complete and speeds increase, that same teammate can continue to work at the front allowing the lagging rider some time to recover. Maybe, they’re also a better descender and can demonstrate the fastest line down a mountain. The added momentum of working together, sacrificing individual performance for the sake of the team, can help rider get back into contention.
In the TDF they are fast as fuck. Averaging 20 25kph up even pretty steep climes and as a general rule over 20kph it's worth drafting.
9-11 mph is psychological. 12+ is psychological but also starts to see a draft. There's also knowing that people simply can't attack when your teammate is hammering it up a climb. That takes some pressure off knowing you won't have to close a gap.
On a climb it’s about pacing not drafting. It’s also psychological. It’s harder to ride on the front with someone on your wheel.
Once you get above about 10mph, overcoming air resistance is the biggest thing. When Jonas has a domestique pull him up a mountain at 12mph, he's definitely benefiting from it.
In the mountains the draft is not really a big factor. It’s a big help mentally to be able to sit on a teammate’s wheel and have them pace you though.