Why do we need fabrics that wick the sweat?

The choice of clothing pieces you make for a ride obviously depends on the temperature, I should say temperatures that you are likely to encounter during your stage.  You will choose them with certain qualities in mind such as wind blocking properties for example, without foresaking breathability.  Remember how we said that perspiration is here to help you cool down to maintain your inside body temperature at 37 C for optimal performance? Well, to aid perspiration in performing its role, you must allow the relative wind to evaporate it at the surface of the barrier, i.e.  the moisture must cross your clothes and be hit by the wind.  Once the wetness has evaporated, it is up to your metabolism to decide if more cooling down is required, depending on the new instant weather conditions found as you progress on your course.

I remember long ago, I just wore a simple t-shirt to ride.  Since it held on to too much moisture I was constantly cool, even when the temperature became fresher with elevation or climate change, or time moving towards the evening.  At some point I got to that paradoxical point.  The“barrier” I had been using was playing adversely on my training by cooling me down rather than warming me up.

Adapting the layers to the moment

A sensible approach to prepare your clothes while riding is to mentally picture what the climate will be like all the way along your ride.  Firstly you should check the forecast for the day, and the for the following day.  This will give you an indication of the temperature it will be when you commence, and the variation of it as you go.
e.g.  You want to start a ride at 4 pm, it is currently 32 C, the forecast for today was for a low of 18, high of 33, but tomorrow morning will be 13 C 23 C because a cool change is forecast tonight; therefore you should plan to take a jacket with you if you will be out for long as the cool change is likely to occur as you ride.

When you start your ride at a hot time of the day, and you know it will become fresher later on, you can take an extra layer with you and simply hang it folded in two on a belt, on the left or right side of your waist.  Said belt can be just a light clip-on belt, such as a triathlon belt used for holding your number, or simply a bumbag belt.  A light, windproof jacket is the best choice.  It saves you from taking with you more layers to block the wind.  This way you will be lighter to climb mountains and hills.
If your windproof jacket has removable sleeves, and it is currently warm but is predicted to be cooler later on, then you can choose to take the sleeves off, hang them on your belt (join the four ends with an elastic band to prevent flapping in the wind); leave your jacket completely open for now, with both sides flying back to avoid the wind drag; this way you don’t sweat for nothing, holding on to some much needed body fluids that you will need to complete your ride.
When you climb higher up in the hills, or if the wind turns, or you change direction, or if a cool change comes about, all you will have to do is re-attach the sleeves on to your jacket, and zip it up.

In the Australian winter, or in the French mountains in even during summer, beyond a gievn altitude, the temperature can drop to just over zero.  It it not unheard of to hit below freezing temperatures in the mountains in France.  You will appreciate a pair of light silk gloves.  These gloves are available in France at a well known sports supermarket for only 8 euros.  These gloves can easily be put in a bum bag, or under the braces of your nicks if you have no bumbag.

In the same weather conditions, an earband can turn a chilly ride to a comfortable warm one.  A few euros will get you one at the same shop.  An earband can easily be transported, slipped under your nicks brace, as it is very light and slim.

If like me, you are shaved or bald, a sport bandana worn under your helmet will fill no less than four roles:

• keep your head fresh in summer, as it will be soaked with your sweat and exposed to the wind.
• keep your head warm in winter, as you tend to sweat less through your scalp at this time and it will act as an insulator from the chilly wind.
• protect your scalp from UVs that go through your helmet gaps, or that hit you directly if you are not wearing a helmet, such as when riding in France, since it is allowed there (although I do not recommend it).
• Protect your head from beestings, as bees have been known to get stuck in your helmet, they will get agitated and sting you in about two seconds flat.  This has occasionally happened to me, stinging me on the one time I did not wear a sport bandana.

A sport bandana can be found for a few euros in the same shop.

Such sport goggles can be found for a handful of euros at the same sport shop in France.

The long rides issue

Crossing climate zones

If short rides (under two hours) have never really been a mind-boggler clothes-wise, crossing different climates and temperatures during your ride can be.
There are various reasons why you could cross very different climates while you are riding.  The first one is the time.  In European summer, or notoriously in Australian winter, when riding from early in the morning well into mid-morning and possibly until noon, you may face a temperature range of up to nearly 20 degrees centigrade.  On top of this, the“feels like” temperature can vary itself from the actual temperature depending on the chill factor generated by the wind, and your own speed.

Different climates can also be crossed while riding across evening dusk during Australian interseasons (Spring or Autumn).  In about one hour, around sunset, the temperature can drop 10 degrees or more just because the sun has just disappeared under the horizon.
In some southern regions of Australia (I am thinking of coastal South Australia for example), the wind can change suddenly to a much cooler southerly.  It is not rare that a 40 C northerly turns into a 23 C southerly within an hour.  If you are riding south at that time, the feels like temperature will drop by over 20 C due to your previously generated perspiration.

If you live in Adelaide, let me share with you this rule of thumb: The temperature at Mt Lofty at sunset usually equals the next day's city forecast low temperature.A bit freaky when the next morning’s forecast in the city is a low of 5 C . . .

A sudden shower with the onset in the hills can also cool everything down quite rapidly.  This is common during the interseasons when a warm and humid wind carrying vapour blows from the sea and rises into the hills where it cools quickly from the elevation.  Vapour condensates and it starts to rain.  The rain itself may not be cold per se, but can be an unwanted dampness coming from outside, cooling you down just from the relative wind, even if you are wearing a rainproof jacket.

The final factor of temperature change, felt temperature again, is hunger.  After so many hours of riding, hunger will remind you that one of the roles of food is to keep your internal temperature constant at 37 C, and even though you are still engaged in effort it may not be enough to keep it your body temperature high, so you will feel cold even in summer.

The inter-season Adelaide Hills pattern

To illustrate the role of all the factors listed above on a practical and true example, and see how complicated planning for a long ride can be, let’s consider a long ride of about 5 hours, in autumn, on a dry May day, forecast at a low of 8 C and a high of 20 C, starting in Adelaide and going well in to the Adelaide Hills for a few hours before getting back to the City.
Let’s envisage two different riding times: a morning start at 7 am and an afternoon start at 4 pm.

The morning start

The sun has just risen, but is still too low above the horizon to warm you up.
Cross Road or Glen Osmond Road are still fresh as it has been a cool night.  It is now 12 C, and you can’t really ride without a jacket over your jersey, or without an extra singlet under your jersey.
As you start your ascent onto Old Mount Barker Road, the effort may lead you to unzip your jacket or unzip your jersey if you have a singlet+jersey combination.
Once you get to the corner at Eagle Rd located at about 400 m altitude, you can feel the fresh wind that is often relieving in summer, but really chilly at this time of year.  You zip your windproof jacket back up, onto perspiration dampness that is evident by this stage.
But soon, on the last bit leading to the woods, you can feel it is getting warmer again with the road getting steeper and being exposed to the sun; then fresh again in the woods, that are still in the shade and the humidity of the night, then hot again as you ascend the second part (Mt Lofty Scenic Route, Shurdington Rd or Blackburn Drive, depending on how steep you like it).  After this you get to that fresh part where the road becomes horizontal again and it is quite windy now, you know, where the TV antennas are on your right.  You are now at 690 m altitude.
If the forecast for that day was low of 8 C, high of 20 C, you can expect a temperature of about 10 C at 9 am about now.  Remember that under your jersey, or jacket, you are all sweaty.  No doubt your tummy will be really cold, and depending on how sensitive you are, you might experience some minor intestinal discomfort in the next hours.
From this time, the next hours will remain cool despite the sun getting higher.  Indeed, your altitude will remain quite high, between 300 and 700 m as you ride through the hills.  These roads stay shady from the peaks of the hills at that time of year.
You will certainly benefit from a flattened plastic bag slipped between your jersey and your tummy as you descend from Mt Lofty to Ashton as the relative wind will make this part of the ride chilly.
The last two hours may be more difficult as you have gone through all of your water reserves, you are hungry since you ate at about 6 am to be able to store as much as possible for this long ride, you are hot, and the sun is now quite high and strong enough to burn your skin as your sun protection has all but disappeared secondary to perspiration.
At some point, the surrounding temperature will be warm enough to make you feel like opening your jacket again since the hills are a chain of ups and downs.  Everytime you open it during an ascent, you will find that you need to close it immediately after the summit, due to the wind.
By the time you return to the city you will have been riding sweat-drenched for over 4 hours, constantly juggling with two wills - opening your jersey on climbs but trying avoid getting chilled by the wind.  It goes without saying that you would do well to keep that plastic bag to protect your tummy against the chilly wind on your final descent to the city.

The afternoon start

The afternoon ride is not a great time to start, as it is the end of the school day and most jobs.  The roads are packed and filled with exhaust fumes.  You can’t wait to climb up Crafers veloway, looking down on these poor commuting motorists stuck on the highway.
At that time of the afternoon, the temperatureid fantastic to ride, still about 18 C, and maybe a gentle sun if you are lucky.  As you ascent Mt Lofty slopes, it is both getting cooler but the position of the sun, sometimes right in front but mostly on your right, is perfect to warm you up a bit.  You still sweat, and so at the same corner as for the morning ride you must close your jersey.  You may keep it closed now for the rest of your ride, as you will plunge into the shade for the day.  The sun is now well West, and the Hills themselves cast shadows on the entire Valley, holding the temperature at about 12 C for the next two hours.
As you cross sunset, at around 5:45 pm let’s say, you lose about 2 degrees per hour.
You use your front flashing lamp to ride safely in the winding roads of the Hills, you go down Gorge Rd for a while, and turn left onto Corkscrew, then up to soon reach 500 m altitude again on Montacute Road.  The wind is now getting really chilly at that point on your way to Cherryville.  It is so chilly that you have to slow down, or stop, to put your silk gloves on under your riding gloves, and to put your earband on.
You can see the distant sunset if you look West, it’s now all red and will be like this for a while.  Meaning it is a clear evening with a forecast low of 5 C tomorrow.  Arghh, Fabien’s rule of thumb applies, meaning it is now 5 C at best at Mt Lofty.  And you still have 200 m to climb! By the time you get to Mount Lofty for your second pass, you have opened your jacket half way down again, to evacuate the calories during that last bit from Cleland to Lofty.  At lofty your bike computer indicates 5 C, (well done Fab, spot on).  Now you are riding down Old Mount Barker Road at 60 km/h, saying thank you to your undergloves, earband, plastic bag, and glasses.

Long rides in French summer

French summer sees really long days right across the country; longer than Melbourne, VIC.  On solstice day, always the 21st of June, days in the South East (le Midi) are the shortest in the country, and here they are still as long as 15 hours and 26 minutes (14:47 for Melbourne at best).  The relative position of the country within its timezone (located much more West than its timezone dictates), and the relatively high latitude makes the temperature build up during the afternoon rather than during the morning.  This is why it remains rather cool until late in the morning, and rather a hot and stable temperature therefore until late in the evening.
These specificities make riding quite comfortable, since the temperatures that you will experience can be predicted quite well.  As a practical consequence, you shouldn’t need to juggle with layers, putting on more and taking them off as you go.
Even crossing mountains doesn’t see great variations in temperature if the sky is clear, as the suns rays are powerful enough and warm up the roads enough to slightly compensate for the natural temperature drop with the higher altitudes.
e.g.  On the 27th of July 2012, the Ventoux climb took me to an altitude of 1912 m, an altitude where the sunny side of Mont Ventoux (Southern face) was still at 27 C, whereas it was 37 C down at the departure point in Pernes-les-fontaines, located at 88 m above sea level.  If you compare this gradient to the commonly admitted 6 C per kilometre we talked about earlier, that is just 5.5 C per kilometre of elevation.