amishboy51

I am NOT a very strong rider; I realize this when I'm out on my bike and feel the wind.

However, as I had this thought again yesterday, I noticed that there really wasn't any wind! The leaves on both the bushes and upper tree branches were barely moving, and the weather app indicated winds of <10 mph.

That got me to wondering: rather than "wind," am I whining about something else? Resistance, friction, whatever? Something that's more discernible to "sensitive" Clydes like me? Ya know, like mass times movement equals whatever-this-is. Does anyone else have a similar thought, or, better yet, an answer?

[Despite my mocking tone, I actually mean this as a serious question. I searched on the forums, but didn't find anything except "real" wind discussions.]

TrojanHorse

Your own movement generates apparent wind, which is why people grouse about a head way both ways on a ride.

MattTheHat 

And Clydes have more surface area. If the wind is blowing, it's generating x number of pounds of force on that area. The larger the area, the more pounds of force.

cyclist2000

You will be glad that there is always a breeze when riding the bike in the heat of summer. I was riding today into a 10 mph wind and on the way back with a tailwind I was riding at 16 mph it still felt like I had a headwind since I was riding faster than the wind speed.

cyccommute 

It’s not that your movement generates wind, your movement is shoving air out of the way. The air is just minding its own business until you come along and bash it out of the way. Think of yourself as a TrojanHorse or amishboy51 sized battering ram.

Poor air molecules.

TrojanHorse

That's why I said apparent wind. Obviously you're not generating actual wind, it just feels like it.

amishboy51

Okay, so let’s assume I’m a little “slow” and break it down: what you guys are saying is that first we’re dealing with a “real” headwind, and this is “multiplied” for everyone, and then it’s “remultiplied” for Clydes?

And y’all just “ignore“ it and continue riding?

cyclist2000

What's the other option? to not ride? No way.

ups

Air resistance makes you stronger. As you get stronger the wind won't be as noticable to you, so just get out and ride more. For a longer explanation see below.

The first part of your question is just a physics issue. The force (or energy you need to apply to your pedals) is equal to the Mass you are moving x the acceleration/speed. (F=MxA "Thanks 12th grade physics teacher Mr. Dooley!").

Given an equal force such as a constant 10 mph wind, things with a larger surface area need greater force / resistance applied to overcome the force due to the larger surface area. Each square foot has the same force being applied, but bigger people have more "square feet" to which that force is applied. So in addition to overcoming the greater amount of weight needed to move a larger person, that person will use more energy to overcome the air resistance or wind.

Overall the greater forces needed make it seems even more or "multiplied".

amishboy51

Thank you. I was never very good in science, let alone physics (I think I peaked when making a dinosaur diorama in fourth grade ), but I was hoping someone would post info that would provide a “scientific” explanation for what I thought, but couldn’t quite put into words. And, as a bonus, more motivation (again) to get off my butt and lose weight!

DrIsotope

I dunno. On any online forum, there are plenty of folks who generate their own wind. It can get downright blustery on here sometimes.

MattTheHat 

Exactly...embrace the pain.

Russ Roth

Just a function of being bigger, out on the road when I ride with my wife I can loose her if I try hard though she gets a great draft off me, if we ride into a strong wind she can't pull away but neither can I. She isn't as strong but is half my mass and doesn't feel the wind for sure. on the trainer which doesn't account for wind I have no trouble dusting her on the same course, she started the last 13mi ride a min early and I finished 4 min before her, lack of wind/pushing into the air is nice.

bobwysiwyg

We've had what I consider has been a fairly easy, mild winter. I began riding Outdoors in February. Not every day, but whenever my wimpy criteria was met. I use an app, "EpicRide." Quick , easy, visual. Gives you a quick easy way to determine a ride, today, tomorrow, whenever, at a glance. Wind direction and perceived force by arrows of varying thickness. It includes real and apparent temps, cloud cover and chance of precipitation for the time and selected route. Very useful. You'll know how to ride in the winds, outbound, inbound, or cross-wind. Plan accordingly.

NMRoller

Just realize you are flying, even if you think you are going slow. Enjoy the cooling breeze and fresh air.

stevel610 

Did 16 miles on my fixed gear today. Paved river trail. Felt like I was flying on the way out. Hit with a strong headwind when I turned around. Slower on the way back but got a better workout.

SethAZ 

Three days ago I was out riding with some fairly strong gusts from a particular direction. I could see the direct effect of those gusts at different points in the ride depending on whether it was coming at me from the front, hitting me from the side, or behind me. I recall at one point looking down and I was riding through a particularly strong gust of wind. I was doing under 15 mph and putting out around 220 watts of power. In still air, on flat ground, that 220 watts would have had me up around 20 mph or so. The effect of wind in cycling is not only real, but as the wind gets faster or the cyclist gets faster, it comes to dominate anything else.

As others have said, the faster you go, the greater the percentage of your power output is going into nothing more than pushing the air out of your way. This effect goes up quadratically, ie: with the square of the apparent wind velocity. The effect is the same whether you're generating apparent wind through forward motion through still air, or whether the wind is actually blowing into you. So riding into wind is more or less the same as riding faster into still air. It's not exactly the same because there are other sources of resistance, such as friction in the bearings and drivetrain, rolling resistance over the ground, etc.

Yes, wind resistance goes up proportionally with cross-sectional area into the wind, and we large folk have more cross-sectional area. The funny thing about geometry, though, is that while surface area goes up with the square of the radius of the shape, volume goes up as the cube of the radius, so we're packing more lbs per square foot of surface area than a skinny person. Why does this matter? Downhill riding, of course! A heavy person and a skinny person will both have gravitational potential energy at the top of some hill that is proportional to their mass. The skinny person, however, will have more surface area facing the wind per pound of mass than a fat person will. I've assumed an aero tuck on descents after I spun out in my highest gear and passed skinny group members who were still furiously spinning away trying to get faster. Hey, there's a silver lining in every rain cloud, or whatever that saying is.

Notso_fastLane

Once you get to the point where you're starting to think about these things, that's a good sign that your cycling is improving.

Hold on, I'm going to do physics at you!

The force of wind that you feel, and that actually slows you down, increases as the square of your velocity. That means if you double your speed, the force 'holding you back' is 4 times as much.

Even worse, the power required to overcome that increases as the cube of your velocity. So twice as fast is 9 times as much power. Sounds crazy, but aerodynamic drag (which is what physicists and aerodynamicists call that wind you feel) isn't the only thing affecting you. Rolling resistance also factors in, and that tends (smooth-ish roads and all other things being equal) decreases as you go faster, but only to a certain point.

If you really want to go fast, you streamline yourself. That's why all of the unassisted human powered records are on specialized streamliners and velomobile type vehicles.

I haven't got a power meter yet (looking at getting that this year). There is a road nearby me that is almost perfectly level. I can cruise at almost 24 mph in me velomobile. If I push (<2 minutes max), I can get my speed and sustain 35 mph for about 3 miles. That's mostly aerodynamics.

tallbikeman

I try to follow these simple wind and hill rules on hikes and bicycling. I always like to start hikes and bicycle rides going into the wind. Most of my rides are out and backs so the walk/ride home will be downwind. It is not a perfect world so this perfect situation is not always possible but I do this for most of my bicycle rides and a few walks and hikes. The second rule is start up the hill early so that you can come back down after the turnaround. Again not always possible but I've always found a bicycle ride so much more enjoyable when home was down the hill from where I turned around.

ups

Here's an interesting article on retro vs modern equipment on aero dynamics. Around 13 minutes they talk about the dramatic effect of modern race clothing. 50 watts saved.