'Make a sail' or 'go aero' uphill with a stonking tailwind?

[ColinJ]

I normally go UP the long local Cragg Vale climb and there is usually a SW cross/headwind to contend with. Today I forgot to check the forecast and set off to do my loop in the opposite direction for a change. It was soon obvious that there was a reversal to the usual wind direction. When I got to the summit at Blackstone Edge, I turned left and began my descent. It is normally easy to hit 50+ kph even on the shallow downhill gradient before it steepens further on. Today, the wind was so strong against me that I was only doing 25 kph on the first part of the descent.

I saw a rider coming up the hill towards me at a brisk pace. He had tribars on his bike and was using them.

It struck me that he probably wasn't going much faster up the hill than his tailwind ...

Then I wondered ... If his speed relative to the air was that low, would he have been better off sitting up to catch more of the wind?

It is all very well theorising. I suppose the real answer would be to try both ways using a power meter to keep the effort the same but I don't have tribars OR a power meter.

Somebody satisfy my curiosity - in that scenario and for the same level of effort, 'make a sail' or 'go aero' to go faster?

 

[Rohloff_Brompton_Rider]

My big masculine muscular back caught the wind up Manchester Rd today and I averaged 9mph, which meant I was 5 minutes too early for tea.

 

[rualexander]

The pushing effect of a tailwind is fairly negligible, in normal everyday wind strengths, imagine standing up on a windy day and jumping off the ground, do you get blown any distance?
The main assistance from a tailwind is in the reduction or absence of any air resistance to your forward movement, depending on the wind strength.
Therefore, going uphill with a tailwind, I would say the person you saw would have seen little difference in either position.

 

[2IT]

While the sail effect may not be great, it's an excellent time to change body position. Besides using the muscles at a different angle it opens up the breathing, gives the neck a break etc... Whenever I can, I do.

I normally go UP the long local Cragg Vale climb and there is usually a SW cross/headwind to contend with. Today I forgot to check the forecast and set off to do my loop in the opposite direction for a change. It was soon obvious that there was a reversal to the usual wind direction. When I got to the summit at Blackstone Edge, I turned left and began my descent. It is normally easy to hit 50+ kph even on the shallow downhill gradient before it steepens further on. Today, the wind was so strong against me that I was only doing 25 kph on the first part of the descent.

I saw a rider coming up the hill towards me at a brisk pace. He had tribars on his bike and was using them.

It struck me that he probably wasn't going much faster up the hill than his tailwind ...

Then I wondered ... If his speed relative to the air was that low, would he have been better off sitting up to catch more of the wind?

It is all very well theorising. I suppose the real answer would be to try both ways using a power meter to keep the effort the same but I don't have tribars OR a power meter.

Somebody satisfy my curiosity - in that scenario and for the same level of effort, 'make a sail' or 'go aero' to go faster?

 

[slowmotion]

My guess is that the "sailors" could be on to a good thing if the sail is big enough. With a big sail, you are capturing a larger force to propel you along the road. With a tail wind, you will never be forced along faster than the windspeed itself when going in a straight line with the wind directly behind you. However, if you hold out your billowing hi-viz jacket and tack down the road, you could reach totally awesome speeds. I hope this helps.....

 

[Rohloff_Brompton_Rider]

Ok, if a tail wind is negligible, explain to me why the same wind strength but as a head wind, is why on many occasions, I have had to pedal down the 6% mile long section on the way home?

 

[machew]

View: https://www.youtube.com/watch?v=GOnM1lXENj4

 

[raleighnut]

View: https://www.youtube.com/watch?v=GOnM1lXENj4

 

[Yellow Saddle]

Ok, if a tail wind is negligible, explain to me why the same wind strength but as a head wind, is why on many occasions, I have had to pedal down the 6% mile long section on the way home?

Because the wind assistance was not enough to overcome rolling resistance?

 

[Yellow Saddle]

Sail away but don't expect huge benefits. Your body is smaller and forms a poorer sail than you think.

 

[2IT]

My body feels like an umbrella or parachute into a headwind and a sail in a side wind.

 

[MiK1138]

What is this tailwind you speak of

 

[400bhp]

The pushing effect of a tailwind is fairly negligible, in normal everyday wind strengths, imagine standing up on a windy day and jumping off the ground, do you get blown any distance?
The main assistance from a tailwind is in the reduction or absence of any air resistance to your forward movement, depending on the wind strength.
Therefore, going uphill with a tailwind, I would say the person you saw would have seen little difference in either position.

Is this because essentially you create a (for want of a better phrase) "dead zone" in front of you as your back is shielding the airflow? When the wind is directly behind Ithere appears to be little or no noise.

 

[rualexander]

Its not so much that you create a 'dead zone' although you do to some extent if the tailwind speed is greater than your road speed, its more that the air is flowing the same way as you are going so you don't have to push through it.
The reason it is quieter with a tailwind is because you don't have air rushing over the front of your ears.

 

[ColinJ]

I enjoy the quietness of riding with a tailwind even more than the help it gives me. One minute I am battling a deafening crosswind then I turn a corner and the riding becomes easy and silent - bliss!

Yes, but depressingly rare ... The valley system round here seems to funnel the winds in a strange way. It is often possible to do a circular ride and get cross/headwinds 75+% of the time!