....Well crap

[Woldan]

you never tire of being wrong.  you has said powerlifting innumerable times.  we used visual and written examples o' powerlifting and you didn't change toon. so now it is strongman?  *chuckle* fine.  describe which strongman events you would recommend to longknife. while you do so, we will amuse our self as we picture famous strongmen showing off their rock climbing skills.

Yes, I mis-labeled what I meant, big deal.

But you do not seem to understand the difference between an event and exercise. Why would I recommend an event? I recommend strongman exercises, which include powerlifting exercises.

 

Oh, and when imagining strong men rock climbing simply think of the natural ones.

 

 

am wondering how much help you is gonna need to understand drag and aerodynamics. 

"At high speeds, racing a bicycle can feel like swimming through water: you can really feel the air pushing against you and (as we've already seen) you use around 80 percent of your energy overcoming drag. Now a bicycle is pretty thin and streamlined, but a cyclist's body is much fatter and wider. In practice, a cyclist's body creates twice as much drag as their bicycle. That's why cyclists wear tight neoprene clothing and pointed helmets to streamline themselves and minimize energy losses."

80%

is not anecdotal 80%. is physics.

sheesh.

HA! Good Fun!

If you knew anything about aerodynamics you'd know that there are no fixed numbers like ''80%'' because it depends on the speed.

 

You should read my post again. Drag always plays a role, but it only becomes a major role on stages with very high average speeds and in oval cycling. On changeable terrain where 90% of the time is spent on fighting hills drag becomes rather insignificant.

Watch tour the France, they will wear a streamlined tear drop shaped helmets and triathlon handle bars on stages that feature long straights with little elevation change, once they go for stages that feature many inclines and is mainly mountainous they will not be wearing those drag decreasing devices because their beneficial effect becomes insignificant. If drag was such a major player at those speeds they would be using the lowest possible stance , wearing streamlined helmets while going up steep hills.

But people don't do that, in fact, they will stand up and use their body weight to aid pedaling, the stance that creates the most drag possible, because they're not fighting drag there.

I could tell you from first hand experience that when I've started to use a triathlon handle bar, which is one of the few devices that do a comparatively good job at lowering drag in cycling, my times only decreased by mere minutes on my 3 hour ride. I tested this the whole summer fir literally thousands of kilometers. Changing from wet lubricant to dry and investing on high quality wheel bearings made a bigger impact.

 

Or, since you don't like hearing about my experiences gather some first hand experience yourself, for once. Grab your bike, install a triathlon handle bar and wear a streamlined helmet, choose a cycling route that features a lot of steep inclines and use your most drag efficient stance. Then install new quality wheel bearings, the best shifter and use the best lubricant you can get your hands on, try it again - without your helmet and the handlebar. Report back.

 

Or, if you don't like getting your hands dirty to prove a point, you can also use this calculator: http://www.gribble.org/cycling/power_v_speed.html

Used my personal parameters, 100kg, bike weight 8kg, frontal area 600cm², 20 degree slope, 5% drive train loss. 5% is the amount of power lost through mechanical friction of an average bike. High end components will give you 3%.

 

Slope: 20°

Speed: 10 km/h.

Gravity: 633 Watts

Drag: 1.46 Watts (0,8%!)

Loss: 29 watts (Drivetrain = 5%)

 

Loss through mechanical friction is 19 times greater than aerodynamic drag.

 

Now at high speeds on a flat stage its a different story:

Slope: 2°

Speed: 40 km/h.

Gravity: 237 Watts

Drag: 330 Watts

Loss: 33 Watts (Drivetrain, 5%)

 

Like I said before, on stages where the majority of the time is spent on trying to haul your butt up a hill drag becomes insignificant and mechanical friction plus rolling resistance becomes the factor #1. In oval racing and on long high speed courses drag becomes factor #1. 

Edited January 22, 2015 by Woldan

[Hurlshort]

So, exercise is good and stuff.  Keep up the healthy living.  

[Osvir]

Are you good with pixel art?

[Gromnir]

"I could tell you from first hand experience "

 

quit it. just stop for chrissakes.  when is you gonna give up the anecdotal nonsense? doesn't matter if it is your or ours.  you Feel like aerodynamics is unimportant.  you feel like orange juice and strong man exercises is a key to stronger immune system. give it up, please. singular examples and anecdotal evidence is pointless. useless. and observing the importance o' speed as a variable is funny considering we already made that point.  "air resistance is the primary source o' drag a cyclist faces.  the role o' air resistance increases as does speed."  sure, 80% is a ballpark figure, but it is illustrative when speaking of actual cyclist speeds such as you described above and elsewhere... 100kph and such?

 

and you not know how to use your own freaking calculator.  am gonna quote from previous linked PHYSICS article, 'cause we is repeating self, and why should we waste effort if you won't read anyway?

 

1) "Mechanical drag is pretty much a small, fixed number. It hardly varies from bike to bike. Even the new fancy ceramic bearings do very little to make an appreciable dent in mechanical drag. The chain is the biggest source of friction, and there haven’t been any advances in chain technology in 100 years." try to grasp the notion o' a constant.

 

2) when considering the impact o' air resistance, "The drag force is important, to be sure, but we are here to talk about power. Power is the product of force and velocity. But, what velocity do we use – the road speed or the effective wind speed? In this case, we use road speed. The speed of the wind in your face determines the drag force; the speed at which we drive the bike determines how much power it takes to overcome that drag force. Multiplying the above equation by road speed, we get:

 

Power to Overcome Wind Resistance = ½*(air_density)*CdA*V_wind^2*V_road.

 

 

In any conditions with ambient wind, these two velocity terms will not be the same. Naturally, they are related since increasing road speed will increase the headwind. We can solve the equation for any given situation.

 

When dealing with wind, you can’t control the air density or the ambient wind. Since you want your road speed to be as high as possible, the only variable left under your control at a given power output is your CdA. CdA can be managed via bike equipment, clothing and rider positioning.

 

Bike equipment that has been demonstrated to reduce CdA includes deep-rimmed and disc wheels, wheel covers, aerodynamic framesets and forks, and handlebars that present a low profile to the wind. These components can reduce both the Cd and the A parts of the CdA figure.

 

A bike rider can reduce her CdA by wearing tight-fitting clothing. Anything that flaps in the wind increases CdA. An aerodynamically designed racing helmet can make a significant improvement in CdA as it makes the rider more streamlined, lowering the Cd.

 

Finally, the rider’s position on the bike is the single largest determinant of CdA. If you sit up straight, your CdA will be high. If you bend over and tuck your chin down into your chest, your CdA will be lower.

 

The CdA of the combined bike and rider in a triathlon can fall into the range of about 0.25 to 0.33. I will note that very few people get as low as 0.25; the fat part of the bell curve seems to be in the 0.28-0.31 range and plenty of folks are over 0.33. Running a few examples…

 

CdA = 0.28 or 0.31

V_wind = 20 mph

V_road = 20 mph (ie, a calm day) 

Air_dens. = 1.22

 

The power to overcome wind resistance at 20 mph on a calm day can be either 122 watts or it can be 135 watts, in this example. That is 13 watts difference, equating to about 8 minutes in an Ironman for an AG racer. Just what is the difference between a rider with a CdA of 0.28 and another with 0.31? Probably nothing you can see by just looking at them. One might or might not “appear” any more aero than the other. They could have identical bikes and equipment, and fitness, and be coming into T2 eight minutes apart simply because one tucked his head down for 6 hours. If they do happen to come into T2 together, one twin will have ridden 13 watts harder, and will be easily outrun by his buddy.

 

Without specific and careful testing, it is hard to know for sure whether two similar positions have a similar CdA.

 

Contrary to a bit of conventional lore, you don’t need to be fast to benefit from lowering your CdA. In fact, the slower you are, the more time you save by a given amount of CdA reduction. A deep-rimmed front wheel might be good for Chris Lieto, but it is really good for you and me.

 

Another thing you might note from this article is that, while cyclists tend to not think much about tires, the choice of tires can have a bigger effect on saving time than does the selection of aero bike gear or bike positioning.

 

You might also note the role that weight plays in these equations. The total bike and rider mass enters the equations in just one place (tire drag), and its effect is multiplied by speed. CdA, on the other hand, is multiplied by speed raised to the third power. In a sense, reducing your CdA is three orders of magnitude more important than saving weight when on flat ground.

 

3) ok, now for gravity

 

... and am not even gonna bother with 20° stuff as an illustrative example o' something typical, especially with your 60kph nonsense earlier. 

 

 Power to Lift the Bike up a Hill = M*g*[sin(arctan(slope))]*V_road, where

 

V_road = Road speed, as before

M = Weight of bike and rider and gear

g = The gravitational acceleration (9.

sin(arctan(slope)) = The sine of the arctangent of the road slope

slope = road slope, expressed a percentage: rise divided by run. A road that rises 6 feet for every 100 feet of horizontal travel is a 6% slope.

 

The multiplication of the V_road and sin(arctan) terms together essentially spits out the velocity in the vertical direction – how fast you are lifting the bike. The rate of lifting, times your weight, times the gravity constant…gives you the power required to lift the bike. Again, that power is used up and is not available to drive the bike forward. 

 

Riding up a 4.5% slope at 200 watts will net me around 10 mph. About 170 of those watts are being used in lifting me up the hill; only 30 watts are moving me forward.

 

Now for the fun part – rolling over the top. If all those 200 watts didn’t go into driving me forward, where did they go? Energy is conserved, right? You bet – those extra watts got stored up as potential energy. When you begin to coast downhill, you pour out that stored gravitational potential energy. On that 4.5% grade, I am going to coast up to about 30 mph if I just stay in the same sitting-up position on my bike with a CdA of 0.31 (I’m a timid descender). I’m producing zero watts, but what is going on in total?

 

Gravity is doing all the work for me – producing about 530 watts! That’s the wattage requirement for traveling at 30 mph and overcoming wind and tire drag. Every watt you spend getting up the hill is returned to you coming back down. However, there is a catch. You don’t get the time back, only the power. The reason is that you went up slow and lost very little power to the wind. When you come back down fast, you lose lots of power to the wind. So, while the total energy and power is preserved riding up and coasting down, you lose time in the hills because of wind resistance.

 

Why do hills slow us down? Aerodynamics. At a given bike + rider weight, and with a given amount of fitness, the fastest way up and down a hill is to have good aerodynamics. That’s an interesting twist, eh?

 

possibly significant is the following from Doctor David Swain, an expert on sports medicine

 

http://www.sportsci.org/encyc/cyclingupdown/cyclingupdown.html

 

quoted starts

 

As indicated in the following equation, there are three primary forces to be overcome in bicycling: rolling resistance, air resistance and gravity:

 

W = krMs + kaAsv2 + giMs

where W is power, kr is the rolling resistance coefficient, M is the combined mass of cyclist and bicycle, s is the bicycle speed on the road, ka is the air resistance coefficient, A is the combined frontal area of cyclist and bicycle, v is the bicycle speed through the air (i.e. road speed plus head wind speed), g is the gravitational acceleration constant, and i is the road incline (grade; however, this is only an approximation, as the sine of the road angle to the horizontal should technically be used).

 

On modern bicycles with narrow, high pressure tires, rolling resistance is negligible. Since the power required to overcome air resistance is proportional to the bicycle speed cubed (if there is no wind, and s = v), an exponential increase in power is needed as the cyclist attempts to increase speed.

 

Going uphill adds gravity to the forces that must be overcome. Since the cyclist has a finite power supply, he or she must necessarily slow down in proportion to the steepness of the hill, if steady-state aerobic metabolism is to be maintained. While this effect of hills is obvious, more subtle effects of this shift in forces have a dramatic impact on the competition.

 

end quote. now here is where the good dr. 

 

now, as noted already, speed is obvious extreme important when considering this topic, but for every uphill climb, there is a downhill as well and aerodynamics again. furthermore, sadly for woldan, descent takes less time than the ascent.  why is that a factor? 

 

"Small cyclists excel at hill climbing because they generally have greater relative aerobic power (VO2max in ml·min-1·kg-1 ) than do large cyclists. This is also a consequence of scaling geometry: relative to body mass, smaller organisms have greater alveolar and capillary surface areas in the lungs, greater capillary surface areas in the muscles, and greater cross-sectional area of arteries for the delivery of blood."

 

the small cyclist, regardless o' woldan's anecdotal misconceptions about strength, has an advantage on the slow uphill climb compared to the larger and seemingly stronger cyclists, whose actual advantage comes on the downslope where they gots a better mass/acceleration ratio.

 

"Scaling reveals that larger cyclists have a greater ratio of mass to frontal area. They therefore descend hills faster as a consequence of purely physical, not physiological, laws. Since the larger cyclist has a greater mass, gravity acts on him or her with a greater force than it does on a smaller cyclist. (Note: A common misconception is to note the equal acceleration of two different sized objects in free fall in a vacuum, and assume that the force of gravity on both is equal. The force on the more massive object is greater, being exactly proportional to mass, which is why the more massive object is accelerated at the same rate as the less massive one.) While the larger cyclist also has a greater absolute frontal area than the smaller cyclist, the difference is not as great as that for their masses. Thus, the larger cyclist will attain a greater s3 before a balance of forces results in terminal velocity."

 

unfortunately for woldan, uphill takes longer than downhill, and time is a multiplying factor, so once again we see an advantage for the smaller and more aerodynamic cyclist.

 

you is getting constants and variables confused and is mindless adding in numbers without understanding what they mean.

 

oh, and the VO2 max numbers is also figured into our rock climbing hypothetical... and showing us smaller guys from a gym is not in anyway diminishing the observation that strongmen and powerlifters (*chuckle*) is having less efficient builds and strength for an activity sch as rock climbing. the guys at the top o' the "sport" can barely reach the rock climbing wall with their arms fully extended past their chest and gut, and they is still needing to carry far more total mass up the rock wall wherein dynamic strength and endurance is far more vital than is the ability to lift large weights in a single move or over a relative brief period o' time.

 

oh, and since you like pictures

 

 

compare to your picture above.  this guy (silly pic, but is Alex Honnold, arguable the bestest rock climber in the world) is hard, but he is built complete different than the guys you pictured above. can your pictured guys climb rock walls? is likely, but they is working at a disadvantage 'cause they carry more weight and if they is training to be strongmen, they got exact the wrong strength... hell, recall that you told us you don't even sweat when working out with weights.  imagine a sweat-less rock climber and we will show you a guy with heat stroke. so, compare one of the world's elite rock climbers to an elite strongman

 

the exercises (not events) the strong man did to become elite is what got him his noble physique.

 

whatever.

 

HA! Good Fun!

Edited January 22, 2015 by Gromnir

[Nonek]

Sewing. I find it immensely soothing, while the hands are busy ones mind can fly away on whatever flights of fancy one wishes. Good practice for listening to Mrs Nonek tell me about her day, soap operas and various celebrity shenanigans.

[Woldan]

I'd be tempted to spend another half an hour on an answer but I rather spend my time on cycling and lifting than talking about cycling and lifting, to someone who does not even read my posts correctly. 

 

I'm off now to increase my power lifts and drink some delicious orange juice, feel free to spend more time on your research. *snickers* Which I, to get back on topic, wholeheartedly recommend as hobby!

[Blarghagh]

That wall of text was surprisingly informative and well put together.  I'm almost sad you wasted it on Woldan who will just brush it off.

 

EDIT: Ninja'd by what I was talking about. What a coincidink.

Edited January 22, 2015 by TrueNeutral

[Malcador]

Sewing. I find it immensely soothing, while the hands are busy ones mind can fly away on whatever flights of fancy one wishes. Good practice for listening to Mrs Nonek tell me about her day, soap operas and various celebrity shenanigans.

Married life sounds like hell.

[Nonek]

Each day is better than the next. I'm looking forward to hell.

Edited January 22, 2015 by Nonek

[Malcador]

Why it is good to marry under a fake identity. Then you fake the death of a nonexistent person to escape the marriage.

[LadyCrimson]

Good thing I never wanted to be a pro athlete. Apparently there's a lot of math involved.

Me I'm the sort who just likes to ... get on my bike and ride. I like the wind in my hair.

 

[Gfted1]

I powerlift while biking. BOOYA!

 

Nah, Im kidding. I get in my car and back down the driveway just to check my mailbox.

[Gromnir]

Good thing I never wanted to be a pro athlete. Apparently there's a lot of math involved.

 

you joke, but at the higher level o' sports, you is correct that there is a great deal o' math involved. sure, the athlete himself may have difficulty with long division, but considering the multi-million dollar investments in many sports, not to mention nationalistic pride, there is invariably somebody looking at the maths. trainers, coaches and equipment designers is frequent needing to understand math as much as somebody is considering human nature and diet and whatever. the maths is excellent at dispelling the myths that spread 'cause some folks can't get over what they believe they know from personal experience.

 

take twin freestyle swimmers with exact same physique and form. both twins is wearing exact same make, brand, and style o' suit and goggles. twin A has a more powerful stroke and he kicks faster than twin B. twin A takes more strokes per second than twin B.  so, explain why twin B always wins in races against twin A.  the athletes can't explain. the coach with 30 years of experience might not have been able to explain such results.  a physicist or expert in caviation who is having access to video footage o' the swimmers from an underwater pov likely could explain the seeming counter-intuitive results. 

 

HA! Good Fun!

[Blarghagh]

I know it's a hypothetical, but what would cause something like that? It's kinda bothering me now, like a riddle I don't know the answer to.

[Gromnir]

I know it's a hypothetical, but what would cause something like that? It's kinda bothering me now, like a riddle I don't know the answer to.

as strange as it sounds, water is fragile and human swim strokes is too violent to be genuine efficient at propelling a person through water. a significant powerful and violent enough force will cause water to enter a low-pressure vapor state.  as counter-intuitive as it sounds, a powerful swimmer who kicks and pulls too hard through the water is capable o' creating cavitation, a low-pressure state in water that functionally slows the swimmer. the powerful swimmer sudden is pushing against a gas instead of a liquid and the low pressure he creates actual has a tendency to pull the swimmer backwards. as such, a faster and more powerful stroke is not necessarily better at propelling a person through water.  is mighty unnatural for a swimmer to slow the start o' his stroke in the water to go faster.  

 

lets see if Gromnir can find a linky.  

 

go to bottom of page 14

 

http://coachsci.sdsu.edu/swim/bullets/Current44.pdf

 

HA! Good Fun!

[Blarghagh]

Now that I know why, it does seem logical. Strange that logic can seem to go against previously held logic.

[Hurlshort]

That explains why I was always rubbish at swim meets, I was too powerful!

[LadyCrimson]

Weight was why I was/would never be a serious ballerina. Too much muscle weight development (vs. height, especially) when I exercise that much. I could be in the bestest shape in the world and they'd all tell me I was too large. Not that I ever wanted to be a pro ballerina.

 

edit: not that that has much to do with physics (I think). Just a "graceful lines"/light on one's feet type of look expectation while dancing thing.

[Gromnir]

Weight was why I was/would never be a serious ballerina. Too much muscle weight development (vs. height, especially) when I exercise that much. I could be in the bestest shape in the world and they'd all tell me I was too large. Not that I ever wanted to be a pro ballerina.

 

edit: not that that has much to do with physics (I think). Just a "graceful lines"/light on one's feet type of look expectation while dancing thing.

actually...

 

is not an area we can claim expertise regarding, but it not take a physics prodigy to immediate recognize the impact o' mass on rotational inertia and similar such stuff. you wanna spin faster? well, from a simple physics pov, to achieve faster spin you wanna decrease mass and/or keep as much mass as possible close to the rotational access.  in other words, thinner and lighter, yes?  is just one example. am expecting that if we knew more about current dance moves, we could explain why seeming curious, and frequent unhealthy, qualities appear to be demanded by the sport/art.  beyond aesthetics, there is usual practical reasons for seeming bizarre extremes in build-types for different athlete.

 

HA! Good Fun!

[LadyCrimson]

I think in the past it was a preference largely based on physical appearance/gracefulness - it wasn't just "skinny", but also body ratio things along with it (long legs/short torso, small-breasted, long neck/small head). Now it's possible that the physics part of it is one reason why such looks more graceful to the eye during certain movements, but I think appearance wise, such also creates a straighter "line" (like if you held a string from outstretched hand to toe). Like how some people may prefer "leggy" women. A celery stick just looks more graceful and expressive than a stocky pickle.

 

I think in more recent times they've tried to move away from that being a de facto standard body type in some circles but not sure how successful that's been.

[Longknife]

I've been told before that missing a limb could actually make me a better swimmer, though it was never explained how, and I'm not big on swimming anyways.

 

You know what has a wonderful habit of ruining any event where a disabled person has to take their prosthetic off? Little kids. So yeah, not a big fan of going to the public pool.

[Hurlshort]

I've been told before that missing a limb could actually make me a better swimmer, though it was never explained how, and I'm not big on swimming anyways.

 

You know what has a wonderful habit of ruining any event where a disabled person has to take their prosthetic off? Little kids. So yeah, not a big fan of going to the public pool.

 

Why do kids ruin it?  

[Malcador]

Like they ruin everything I imagine. Being rude, loud and dumb.

 

Or maybe they steal his prosthetic . If so, he should put one down. Will be a warnings to the rest.

Edited January 25, 2015 by Malcador

[Hurlshort]

Like they ruin everything I imagine. Being rude, loud and dumb.

 

 

 

Ah you mean, being honest and asking questions, of course.   

[Malcador]

Well you would think that way. Hm, he should try scaring them with it somehow. Have to make your own fun, after all.