mschwett 

ok, i'm not sure what "really old picture" you saw but when you refer to "power meters" and bicycles in the 21st century, these kind of devices are what everyone will think you're talking about. they measure force at the pedal, crank arm, or crank spindle:

asgelle

Wrong. Temperature compensation is not the same as temperature measurement. Placement of multiple strain gauges along different axes can compensate for temperature without an direct measurement.

WhyFi

Wind speed has crossed my mind, but only as a curiosity, not as an actionable figure. It's not like I'm going to be okay 15mph winds but then pack it in when it tips to 16.

"What would be my equivalent ride distance with no wind?" is a nonsensical question without a host of other factors, such as, oh, power.

tessellahedron

https://notio.ai/products/notio-ride-tracker
https://velocomp.com/collections/power-meters
https://cdacrr.blogspot.com/
https://www.instructables.com/Biking-Headwind-Monitor/

now you know as much as I do. All measure wind but I doubt any of those will work easily.

so the idea of just getting a power monitor could work but my concern is price. What's the low end?

WhyFi

No, he's talking about power meters.

mschwett 

interesting - would it be easier to do it that way than just measure temperature? or more accurate?

tessellahedron

On mywindsock.com they talk about virtual mountains. That's exactly what I mean.

tessellahedron

msu2001la

Woah - I've never heard of this type of power meter before. It also seems to solve exactly what the OP is looking for (which any type of power meter would also solve).
https://powermetercity.com/product/p...d-power-meter/

It kind of makes sense - measure the wind instead of the power - but there are so many other factors that come into play (gradient, weight, rolling resistance, etc) that I'm confused about how this works without making a bunch of estimations/assumptions. Riding at 15mph with a 15mph tailwind is easy, but it isn't 0 watts.

WhyFi

I've already mention this exact product - I don't need you to tell me about it. But yeah, not really a power meter - it measures everything but power and then maths it out. Direct force power meters are what the vast majority of people think of when "power meter" is mentioned and they are far, far more common. PowerPods/AeroPods are more of a curiosity except for those doing some in-depth testing for aero, Crr, etc.

tessellahedron

I checked and any type of power meter is going to be over the budget I'd picked for an anemometer.

the average mobile phone contains enough sensors to build a basic missile guidance system. Maybe that's why the handlebar power meters are about the same price.

Inusuit

I live in Wyoming. Wind is a given. I can tell if it's too strong to ride and I go home. Don't need the details.

caloso

About $250 new. https://www.theproscloset.com/produc...-arm-172-5mm-1

Yan 

There is an app called "Windy" that I used while touring in Mongolia. It does detailed wind forecasts.

MoAlpha

That 6 mph forecast is the model output for a grid point, maybe tweaked a little by a human, but it is based on large scale weather events and big terrestrial features like mountain ranges or large bodies of water.

The wind direction and speed a cyclist sees bears only the most general relation to the nominal forecast or what any particular terrestrial station is reporting. Terrain routinely causes right-angle bends in wind flow and vortices that can reverse it 180°. Wind tends to blow straight down tree or house-lined roads, regardless of overall pressure gradient direction. Pressure gradients compress and intensify along ridges or rows of buildings when direction is parallel and the same features serve as windbreaks when the direction is perpendicular. Racing sailors see these effects every time they round a point, sail under a bluff, or enter a river. It’s just way more intense and complex on land.

tessellahedron

This is really flat, open country on the edge of the great plains. I've noticed those effects in town but as soon as I leave it's more predictable.
the direction forecast is very likely to be accurate, and the speed most likely low.

all these complications made me want to just measure for myself.

plus this started when I was riding to and from the store 15 miles away. It's different from riding for fun because I can't just quit, or I miss the store (I think I did do that once though).

for now I'm going to try sailflow.com and windy.com and return the stupid anemometer.

kwb377

Seems about as effective as mounting an inclinometer in order to determine when you're on a hill.

tessellahedron

For those invisible hills you're absolutely right!

RChung

This thread is a wild ride.

I've worked on airspeed measuring devices, both to infer power by assuming drag parameters, and combined with an exogenous power measuring device to infer drag parameters. Measuring windspeed or airspeed on a bike isn't *that* hard, but measuring it to high precision and accuracy is. Most of the cheap options are perfectly fine for common uses, but inadequate for some of the kinds of calculations that obsessive people need.

The Aeropod/iBike/PowerPod sorta work, but they're a PITA to set up and calibrate. Considering the options below, I don't bother.

Modern strain gage power meters often have temperature compensation built-in, but they don't have thermometers per se. As Asgelle says, temp compensation is possible w/o knowing the actual temperature. The Quarq DZero has "automatic" temp compensation, but you can also trigger a torque re-zeroing mid-ride. Most "modern" strain gage power meters also have a way to trigger re-zeroing mid-ride.

Just before the pandemic, I bought a used Power Tap wheel as a spare that works perfectly for $150.

If you're truly interested in wind, Pierre's CdACrr app works and you can find a link to an on-bike anemometer on his blog (that costs about $90). He mostly is interested in recording the data and doing post hoc analysis but his app does have a "real-time" mode. But it sounds like you're not directly interested in wind, you're really more interested in measuring how the demand for power increases with the wind. So although $90 is pretty cheap, I'm not sure it's what you really want. I have a handheld Kestrel 5100 anemometer that I mount on a tripod for stationary work, but it costs $300+.

Or you could skip all this and just check with the Weather Service to find out what the wind forecast and measurements are. Note that "official" wind speed measurements are assumed to be 10m above the ground. And, as Bob Dylan pointed out, you don't need a weatherman to know which way the wind blows.

Bald Paul

I looked at the specs and "tech" on the website for that thing, and cannot figure out how it's supposed to work based on speed, acceleration, cadence, and wind. For all it knows, if I'm moving the pedals (soft pedaling) and basically putting no power to the rear wheel while coasting down a steep hill, the device sees acceleration, an increase in wind speed, and movement of the crank and extrapolates a power number. I'm betting it would read much higher than my actual, crank based power meter - the one sans pitot tube, baro sensor, etc.

spelger

that's true and i fully agree with you. but...it can really be demoralizing when heading into a 20mph west wind for an hour with no let up at all. i still do it though.

msu2001la

Most cycling computers have an altimeter, which will display elevation. They usually work by measuring barometric pressure, and will provide a slope gradient by comparing elevation with distance.

I don't need this info to know that I'm "on a hill", but I do like to know the gradient of climbs, especially if they're big ones.

RChung

It has a barometric altimeter and a multi-axis accelerometer (so essentially it has an inclinometer). It doesn't have a built-in speed or cadence sensor; you can link those if you have them.

The idea and theory of these devices is solid; I use the same principles myself. In practice, the implementation of the theory to an actual product is less happy.

RChung

A good power meter substitutes for an altimeter better than an altimeter works as a power meter.

msu2001la

I'm not suggesting that an altimeter is a substitute for a power meter. I also don't think a power meter is a very good substitute for an altimeter.