The only problem I could find in this test was that you did not increase the psi with the increased weight, but you would have also had to put the psi back to normal without the weight. That extra few pounds of psi would have made the descent a tad faster with the weight added. So the rolling resistance was increased with the less tire psi that was needed.
We have a major problem here. It has been proven, that a bulge in the belly area, that even include a 'beer belly', enhances areodynamics. In fact, for that aero advantage the UCI has banned anything 'fairing' in that area!
And that's why he went 3% faster... I'm shocked that someone with a mathematical degree (engineering) got the maths on this so so wrong!!! Yes f= ma but we also have inertia which is also proportional to m. Gravity has to overcome inertia so mass ends up canceling out. I.e it makes no difference. It's all done to aerodynamics 🙄😮💨
I think that you missed an important thing that I have always struggled to understand. Since Galileo, we have known that objects of the different mass but same frontal profile fall at the same speed. Since the lunar landings, we know that a feather and a bowling ball fall at the same speed in a vacuum, because without drag, mass has no effect on acceleration or speed. Therefore it is not about the acceleration, so much as the terminal velocity. The acceleration due to gravity entering a descent is roughly the same for different weight riders, but the terminal velocity in different weight cyclists will increase with weight. This is important, because it isn’t about the acceleration to terminal velocity, so much as the actual terminal velocity. This is why the other variables are so important, and why a smaller cyclist like Pidcock can be so awesome, as he can find other ways to optimise his terminal velocity that have nothing to do with weight.
Well done!!! Yes weight has very very little to do with it as it cancels out in the equation for acceleration. It still affects rolling resistance and once at speed it means the heavier rider has more momentum which is useful when dealing with bumpy surfaces like bad roads or cobbles. The rest is just aerodynamics. The rides with water were faster due to aerodynamics as others have pointed out above. Terminal velocity does not however increase with weight, its just the point the force of gravity becomes equal to the force of air resistance. So again just aerodynamics.
@@woodstock5nathan thanks . I think terminal velocity does increase with weight. The force forwards =mass*g/sin(gradient). Force backward =wind resistance*velocity^2. Terminal velocity is hit when these force are equal ie mass*(a constant for that hill/bike/rider profile)=v^2 . The heavier object will hit terminal velocity at a higher speed if the resistance constant is the same for both riders. I wasn’t sure about this, but found this slightly crappy video which explained it to me last night when I was thinking about it.
@@ianrodd1423 Yes, terminal velocity increases with weight if the area and drag coefficient of the object remains the same. While falling it is reached when Drag=Weight. The lighter the object, the sooner it will reach its terminal velocity but it will be smaller than a heavier's one (if they have the same shape). Google "NASA terminal velocity interactive". It helped me, it might help you.
I've found descending in a car that it goes more quickly than a bike on the same downhill so at extremes weight makes a difference. With the same drag, terminal velocity is proportional to the square root of the weight. A car is a more efficient shape for cutting through the air but it is bigger so probably has more drag overall.
I think there's an error on the right hand column of your chart (with water). One of the entries says 55.0 seconds. I believe that should read 45.0 seconds. That way the average time of 44.8 seconds is correct. Just saying... 😅
Heavier riders will of cours increase the tire pressure and/or use wider tires. If he/she doesn't, he/she is a fool. For this, there should have been a third run with water bottle and higher tire pressure.
I'm more interested in how a decent heavy weight and a decent light weight cyclist perform in different conditions like headwinds, slight inclines and mild descents. I consider myself to be a decent lightweight cyclist and I can fly up hills but my larger heavyweight mates destroy me on slight inclines and into headwinds. I assume there's a point at which our leg power to weight ratio crosses over 🤔
You missed an opportunity to eliminate the aerodynamic and friction factors. Could have just put the pack on for both runs and used a dummy weight or form to give the pack the same shape for each run. Or use lead weights in water bottles. And then additional runs at higher tire pressure to compensate for additional friction due to squish.
There is an error in the table (3:41), the average time without adding load is not 44.8 (+1.5 s), but 47.3 (+4 s). Or is there an error for ride number 2 - 43.5 vs 55sec?
Our apologies, input error when making the table look prettier for RUclips - It should say 45.0 seconds not 55.0 seconds, rest assured that the averages and results have been calculated using the correct times
The aerodynamics of not only body position but the body itself is a big factor in descending speed, or any speed. A heavier rider may(not always) have broad wide shoulders, large calves the size of basketballs, and thick arms and a wide torso, or an XL size helmet. Larger frontal area of all these qualities will be a slowing factor. It helps a small rider like Pidcock descend so well despite low weight.
Taller/heavier riders may have a biger frontal area, but this will be (under cicumstances more than) compensated by the far higher slope downforce - weight rolls.
As mass increases the inertia resistance to movement does at the same rate so mass + inertia results in exactly the same acceleration. So… back to school
If anyone wants to know how dumb and in correct this was you should look up explanation vids on people dropping a feather and a hammer on the moon. It's on the moon as there is almost no air there. Come on is the presenter an engineer??? Do none of the people making this vid not know about inertia???? This is super old physics!
Is Ed 5 and can he not put it on his back, never mind aero 🙄, only makes sense and for safeties sake, how rediculous overall! Leave it to the professionals = GCN
![Furka Pass (east) - Switzerland raw runs [#3]](http://i.ytimg.com/vi/RBemTPJpwlg/mqdefault.jpg)
The only problem I could find in this test was that you did not increase the psi with the increased weight, but you would have also had to put the psi back to normal without the weight. That extra few pounds of psi would have made the descent a tad faster with the weight added. So the rolling resistance was increased with the less tire psi that was needed.
We have a major problem here. It has been proven, that a bulge in the belly area, that even include a 'beer belly', enhances areodynamics. In fact, for that aero advantage the UCI has banned anything 'fairing' in that area!
And that's why he went 3% faster... I'm shocked that someone with a mathematical degree (engineering) got the maths on this so so wrong!!! Yes f= ma but we also have inertia which is also proportional to m. Gravity has to overcome inertia so mass ends up canceling out. I.e it makes no difference. It's all done to aerodynamics 🙄😮💨
Well they could try with an empty bottle of the same size
I'm going to guess sectional density ie. aerodynamics plays the key role. Basic gravity accelerates all weights equally. Wasn't it Galileo at Pisa?
Does but heavier increase max speed I thought
Needs a bib short size bigger too...
yeah, for a white guy
No it's perfect 😳🤭😇
I think that you missed an important thing that I have always struggled to understand. Since Galileo, we have known that objects of the different mass but same frontal profile fall at the same speed. Since the lunar landings, we know that a feather and a bowling ball fall at the same speed in a vacuum, because without drag, mass has no effect on acceleration or speed. Therefore it is not about the acceleration, so much as the terminal velocity. The acceleration due to gravity entering a descent is roughly the same for different weight riders, but the terminal velocity in different weight cyclists will increase with weight. This is important, because it isn’t about the acceleration to terminal velocity, so much as the actual terminal velocity. This is why the other variables are so important, and why a smaller cyclist like Pidcock can be so awesome, as he can find other ways to optimise his terminal velocity that have nothing to do with weight.
Well done!!! Yes weight has very very little to do with it as it cancels out in the equation for acceleration. It still affects rolling resistance and once at speed it means the heavier rider has more momentum which is useful when dealing with bumpy surfaces like bad roads or cobbles. The rest is just aerodynamics. The rides with water were faster due to aerodynamics as others have pointed out above. Terminal velocity does not however increase with weight, its just the point the force of gravity becomes equal to the force of air resistance. So again just aerodynamics.
@@woodstock5nathan thanks . I think terminal velocity does increase with weight. The force forwards =mass*g/sin(gradient). Force backward =wind resistance*velocity^2. Terminal velocity is hit when these force are equal ie mass*(a constant for that hill/bike/rider profile)=v^2 . The heavier object will hit terminal velocity at a higher speed if the resistance constant is the same for both riders. I wasn’t sure about this, but found this slightly crappy video which explained it to me last night when I was thinking about it.
@@woodstock5nathan ruclips.net/video/C6vv5J4vhPI/видео.html
Yep the lighter object will reach terminal velocity at a lower speed.
@@ianrodd1423 Yes, terminal velocity increases with weight if the area and drag coefficient of the object remains the same.
While falling it is reached when Drag=Weight.
The lighter the object, the sooner it will reach its terminal velocity but it will be smaller than a heavier's one (if they have the same shape).
Google "NASA terminal velocity interactive". It helped me, it might help you.
I've found descending in a car that it goes more quickly than a bike on the same downhill so at extremes weight makes a difference. With the same drag, terminal velocity is proportional to the square root of the weight.
A car is a more efficient shape for cutting through the air but it is bigger so probably has more drag overall.
So my aditional 20kg more then lightweight riders gives me around the price of expensive carbon wheels lol
I think there's an error on the right hand column of your chart (with water). One of the entries says 55.0 seconds. I believe that should read 45.0 seconds. That way the average time of 44.8 seconds is correct. Just saying... 😅
You're very right, apologies, we copied it over wrong to the table for the video edit, rest assured our calculations used the correct numbers!
Aero drag from the bag really skewed the results. Should have had him wear the. Ag with a pillow inside to make it more fair
Think you forgot one more force rollinf resistance. Higher weight will increase rolling resistance both down hill and uphill.
Heavier riders will of cours increase the tire pressure and/or use wider tires. If he/she doesn't, he/she is a fool. For this, there should have been a third run with water bottle and higher tire pressure.
I'm more interested in how a decent heavy weight and a decent light weight cyclist perform in different conditions like headwinds, slight inclines and mild descents.
I consider myself to be a decent lightweight cyclist and I can fly up hills but my larger heavyweight mates destroy me on slight inclines and into headwinds.
I assume there's a point at which our leg power to weight ratio crosses over 🤔
I'm sure this is an experiment we can set up! Stay tuned!
You missed an opportunity to eliminate the aerodynamic and friction factors. Could have just put the pack on for both runs and used a dummy weight or form to give the pack the same shape for each run. Or use lead weights in water bottles. And then additional runs at higher tire pressure to compensate for additional friction due to squish.
There is an error in the table (3:41), the average time without adding load is not 44.8 (+1.5 s), but 47.3 (+4 s). Or is there an error for ride number 2 - 43.5 vs 55sec?
Our apologies, input error when making the table look prettier for RUclips - It should say 45.0 seconds not 55.0 seconds, rest assured that the averages and results have been calculated using the correct times
The aerodynamics of not only body position but the body itself is a big factor in descending speed, or any speed. A heavier rider may(not always) have broad wide shoulders, large calves the size of basketballs, and thick arms and a wide torso, or an XL size helmet. Larger frontal area of all these qualities will be a slowing factor. It helps a small rider like Pidcock descend so well despite low weight.
Taller/heavier riders may have a biger frontal area, but this will be (under cicumstances more than) compensated by the far higher slope downforce - weight rolls.
@@overcookit1433 Not necessarily true. None of these relationships are linear, hence why we are always estimating and guessing this stuff.
Why not an empty bottle to keep drag identical?
Can you please do videos on the ride quality and speed of different bike frames
As mass increases the inertia resistance to movement does at the same rate so mass + inertia results in exactly the same acceleration. So… back to school
yeah but i'm 40kg heavier than most cyclists and i'm a rocket on the descents and a legend in the corners. LOL
for the calculations did you assume a spherical ed
Ed is 2d…
I probs carry 4 times that additional weight than Ed naturally 😂
Its called a backpack.
But you don't train with the weight so you are not stronger.
If anyone wants to know how dumb and in correct this was you should look up explanation vids on people dropping a feather and a hammer on the moon. It's on the moon as there is almost no air there. Come on is the presenter an engineer??? Do none of the people making this vid not know about inertia???? This is super old physics!
The experiment should have been conducted in a vacuum...
First thoughts: did the laws of physics change?
0:40 when males finally get pregnant and . . . 'breaking water'🤣
Meet the world's most intelligent cyclist.
Gets given a rucksack to wear, and straps it to his front 🙄
Is Ed 5 and can he not put it on his back, never mind aero 🙄, only makes sense and for safeties sake, how rediculous overall! Leave it to the professionals = GCN