Wind Quantified

meanredspider

Well, kinda

Did 100k alongside the Markermeer yesterday. Unfortunately I had to do the return leg into the rather brisk wind (an old boy at a red light said it was going to be a tough day on the bike). Now, I was on the Foil, with C50 rims and aerobars on but I was dismayed to see at one point I was putting out a steady 280W and only doing 20kmh. There's a Strava segment of near 1k that suggests I averaged 18kmh and 240W. Remember this is pretty much all pan-flat. You're up on a bike track probably 3 or 4 metres above the surrounding land/water.

Once you learn to embrace it as good training - good mentally too. I felt a bit for some guy who was on the same stretch. I passed him and got a reasonable distance ahead when I had to take a phone call from my son. He passed me again. A bit later I caught up with him again and passed him - he looked broken.

itboffin

Proper mental here today, no way I'm going out in that.

rick_chasey

Wind destroyed me on the club run.

ben-----

I did ~60 miles today, 30 into the wind, 30 back again. Averaged 14.3mi/h going, and 18.3mi/h back. Put way more effort into going. Coming back was a doddle and that's pretty fast for me, especially on my old bike. I planned the route so I'd be going into the wind in the first half. I think that's wise. I'd have hated it the other way round I think.

> Wind Quantified
Cycling computer with wind speed sensor, data recorder on. Seems like a reasonable thing.

meanredspider

Just either side of my turning point (literally heading back the way I'd come) I went from 40kmh, 145bpm and 170W to 25kmh, 160bpm and 250W. I could have made it easier for myself by doing a route into the wind first (and there's one with a bit of shelter too) but it is good training and, frankly, a bit like hills are inevitable in the Highlands, wind is almost inevitable in N Holland

dyrlac

Richmond Park was ludicrous yesterday am, at times coming to a near standstill going SW along the top of Dark Hill, and the less said about going up Sawyer (after switching from CW to ACW) the better. Down Sawyer with an almighty tailwind was ace though.

Anonymous

Went windsurfing instead. I am broken

The Rookie

meanredspider wrote:

Just either side of my turning point (literally heading back the way I'd come) I went from 40kmh, 145bpm and 170W to 25kmh, 160bpm and 250W. I could have made it easier for myself by doing a route into the wind first (and there's one with a bit of shelter too) but it is good training and, frankly, a bit like hills are inevitable in the Highlands, wind is almost inevitable in N Holland

On a road bike, aero drag exceeds rolling resistance at about 16-18kph (rule of thumb) aero drag is proportional to speed squared so a 40% increase in airflow (speed plus headwind) doubles the wind resistance, so those values are entirely consistent with a circa 8-10kph wind (tail on the way out, head on the way back) the wind may have been stronger than that but you need to combine that with your own speed to get the total headwind (a wind at exactly 90 degrees to your travel adds a headwind effect in BOTH direction...just not much).

PBo

I was inspired by yogi and channelled my inner beast to power through the wind on my commute.

....mind you, I was sheltered by 3 QS riders most of the way!

IGMC....

meanredspider

The Rookie wrote:

meanredspider wrote:

Just either side of my turning point (literally heading back the way I'd come) I went from 40kmh, 145bpm and 170W to 25kmh, 160bpm and 250W. I could have made it easier for myself by doing a route into the wind first (and there's one with a bit of shelter too) but it is good training and, frankly, a bit like hills are inevitable in the Highlands, wind is almost inevitable in N Holland

On a road bike, aero drag exceeds rolling resistance at about 16-18kph (rule of thumb) aero drag is proportional to speed squared so a 40% increase in airflow (speed plus headwind) doubles the wind resistance, so those values are entirely consistent with a circa 8-10kph wind (tail on the way out, head on the way back) the wind may have been stronger than that but you need to combine that with your own speed to get the total headwind (a wind at exactly 90 degrees to your travel adds a headwind effect in BOTH direction...just not much).

Wunderground would suggest you're quite some way out. Local weather stations were consistently recording 20kph+ and, given the extremely exposed nature of the route, I expect I was seeing about the same as many of these home weather stations

The Rookie

Yes but was it 100% headwind or at an angle?

meanredspider

The Rookie wrote:

Yes but was it 100% headwind or at an angle?

100% on the nose (tail) at that point.

meanredspider

I think that it's important to remember that a bike moving through the air experiences apparent air velocity due to that movement evenly over the entire bike. Wind, on the other hand, has a varying velocity according to height from the ground (what fluid dynamics folks would refer to as the boundary layer). I'd also imagine that, in this zone, the fluid (air) is turbulent. Both would suggest that pressure related to travelling at 25kph through still air is very different from being stationary in a 25kph wind. It's beyond me to be able to calculate that.

The Rookie

There is a boundary layer, but what is more critical is the sheer in wind speed from much slower near the surface to some point much higher where it's at close to the nominal wind speed, weather stations all have the anemometer up high for that reason, that sheer can be very different depending on terrain, being elevated will usually make the wind speed you experience closer to the nominal, but with certain surface features it can have the opposite effect.

meanredspider

The Rookie wrote:

There is a boundary layer, but what is more critical is the sheer in wind speed from much slower near the surface to some point much higher where it's at close to the nominal wind speed, weather stations all have the anemometer up high for that reason, that sheer can be very different depending on terrain, being elevated will usually make the wind speed you experience closer to the nominal, but with certain surface features it can have the opposite effect.

Absolutely. It's one of the reasons why N Holland is so hard from a wind point of view (it's no surprise that the Dutch are so keen on wind power throughout history). Roads and paths tend to be elevated - actually causing an acceleration in air flow where the wind is at an angle - there is lots of open water, fields tend to have ditches rather then hedges as boundaries, it's close to the N Sea and, of course, the whole place is incredibly flat. You can be pretty sure that if a domestic weather station reporting on Wunderground is reporting 20kph, you'll be riding in air moving at around that speed. In Scotland it's very different with plenty of trees, hedges and hills for cover - one of the reasons it was often easy to ride the 10 miles to the Kessock bridge but hard to cross it.

meanredspider

Did 120k today and grabbed this pic to give some idea of what I'm on about with these paths

The Rookie

Not what you'd call technically challenging then!

Nice way to ride with no worries about morons in cars though!

whoof

I worked in the Netherland for a couple of years (but only a few weeks at a time). Almost all my riding was in strong winds and on either a sit up and beg single speed clunker or a 3 speed hire bike. I used to take some sandwiches and plug away at it, stop for lunch somewhere and then find a loop back. Character building.

meanredspider

The Rookie wrote:

Not what you'd call technically challenging then!

Nice way to ride with no worries about morons in cars though!

That's the bliss of it - I absolutely don't need to think just turn my legs over - I can take my brain out of gear. My day job is pretty stressful so 5 hours of this (not literally that straight all the time) is wonderful.