OK. So we all know that it's harder to ride in a headwind; it's obvious... it takes more power. BUT looking at perceived effort only, if a cyclist is riding at X watts, shouldn't it NOT matter which direction the wind is blowing? Yes the speed will obviously change, but if a cyclist is averaging 180 watts in a headwind and 180 watts in a tailwind, it's still 180 watts the cyclist is creating. So if it's the same power the cyclist is creating, shouldn't it feel the same whether there is a head vs tailwind?

I ask this because, to me it still feels like significantly more effort to do the same wattage in a headwind vs a tailwind even when keeping the power wattage the same.

there is more to riding a bicycle in the real world (vs like Zwift) than your power output. road surface, watching for hazards, weather (incl wind) etc are all fatiguing and not directly related to power production.

for me I enjoy the sensation of speed, so it feels a lot easier to make a given power with a tailwind than a headwind. perhaps its also more fatiguing to stand up in one place with the wind at your face than at your back, although I wont pretend to know why that would be (physiologically)

One of the main differences will be crank inertia. Similar to when climbing. Slower speeds mean lower crank inertia.

That, and also wheel inertia. Plus, riding into a headwind, you have to re-accelerate the combined weight of you and the bike as each pedal passes through top and bottom dead center.

I think for me it’s the perceived sense of speed. Mentally I know at X watts I should be going Y speed. When I encounter a head wind Y speed isn’t achieved so I end up dialing it up to get to Y speed.

But what the person said before me makes more sense.

I find one of the advantages of riding with a power meter is that when you can see your power output then you stop worrying about the resultant speed.

That's interesting. Personally, I think it's easier to maintain same power in a headwind than a tailwind. I always presumed it was a combination of differences in crank inertial load and in convective cooling.

I guess i’m broken.

I honestly don’t mind headwinds.

But all my cycling friends hate them.

My guess is that’s because I don’t use a speed display or power display and simply enjoy the ride, while they see their speed and power, and think they are getting a raw deal.

Lower or higher gusts are always present. When come from the front, they produce short, intermittent surges of power that muscles don't like at all (tail wind generates the opposite, which is perceived as refreshing for muscles). Breathing is always a little more difficult with front wind (I never could explain this).
Then: speed is lower, wind noise is higher - these contribute to overall decrease in comfort, which psychologically is perceived as making a bigger effort.

Things can get pretty warm with a decent tailwind.

I was thinking that just yesterday. On a 4.5-hour ride, first half into the wind, I stayed nice and cool; with the wind at my back; second half, I was uncomfortably warm.

Yes, there is a big perceived difference between a steady headwind and a very gusty headwind. When you're working against, say, a steady 12 MPH headwind, it slows you down but you put down whatever power you desire and accept the speed results you get. But a 12 MPH wind with sudden 30 MPH gusts is something else again.

Ot this (present conditions in Minneapolis at this moment):

Reno now, Still hate it.

uh, yeah. mph or kph?

Mph. Sorry, it's from noaa.

I'm pretty happy if my average speed riding against the wind and with a tailwind is about the same speed I would ride with no wind. But it still seems to require a bit more power riding against the wind.

I find by keeping my cadance in my normal range (60 - 70 rpm) at moderate power levels against the wind I still have enough strength in reserve to deal most wind gusts. With 3 x 7 speeds available, even though 8 are redundant, I can always find one that keeps me at my optimal cadance.

Average power doesn't mean it will feel the same. As some mentioned, the bike slows more between each pedal stroke when fighting a headwind, or climbing a hill. So, the average power may be the same, but the peak power (force) during the pedal strokes will be higher when riding against a larger force (wind or hill).

I also agree, that head or cross winds, can generally just be more fatiguing. After all, we are still balancing on two wheels and the effects of head and cross winds makes that a little bit harder. Or sometimes a lot harder.

I ride with more lean forward, more elbow bend and considerably lower shoulders when I go upwind. So more (approximately static) muscle use and potentially more constricted breathing, both resulting in more hurt (to put it in terms we all understand). Both the tensed muscles and reduced oxygen add up to more lactic acid at the same power output.

A strong headwind tears up my eyes, even behind glasses, and seems more difficult to breathe verses wind from another direction.

Momentum is proportional to velocity.

Energy is a function of velocity squared.

Power required to overcome aero drag is a function of velocity cubed.

With all of the above, I could see if there were inherent differences in headwind versus tailwind.

Interesting experiment to keep to a certain wattage into and with a wind. Will have to try it. I would think the difference in speed could be around 5 MPH. However, I would think that we all have experience in riding in headwinds, the preconceived notion of it still being more hard in a headwind might color one’s perception.

The question was how does it feel at the same power output, not the same speed which would obviously be much harder.

Oh I know. I was just trying to make the point of things being non-linear, AND, the non-linearlessnesses are unequal. It's complicated, and I don't have the answer. But I know your fundamental question of same power in each direction, does it feel the same? I guess it should, because power output should take into account everything. But does it feel the same, if same human output, but one way wind in face and other way wind at back? I don't know. I've been wrong enough to not assume until I can math it out somehow.

If I'm just holding the same target power, I don't think it really matters to me. I spend a lot of time climbing, and a headwind more closely mimics the demands of a climb, so I don't find the greater deceleration forces to be much of a problem. Coupled to that, I'm lucky to be able to hold a fairly aerodynamic position with a flattish back, so I don't pay as big of a penalty for headwinds.