Draft Dodges

Originally written for Triathlete magazine

Drafting?!? Did you spit? Hhhcccchh Thhpppp! Parasite’s Charter…, not REAL triathlon…

Don’t turn over in disgust just yet though. There’s more to drafting than cheating on your fellow competitors (in races where it isn’t allowed) or taking things easy until the run (in races where it is). Even if you only ever compete in non-drafting triathlons there are big benefits to be had from drafting in training and if you do compete in drafting triathlons it’s essential to know how to make the most of the cycle section - be it to conserve energy for the run, to catch up the stronger swimmers or to stay away from stronger runners.

The invisible pocket

The draft effect occurs as an object, you on your bike in this case, moves through air. The air in front gets squashed and the air behind gets stretched. If you were aerofoil shaped then the air would split smoothly in front and join smoothly behind but you’re not and it doesn’t. What happens is that the squashed air in front resists forward movement and makes it feel like hard work and the stretched air behind sucks more air in from around about creating a pocket of ‘dead’ air which moves along just behind you. Somebody riding in this pocket, or slipstream, feels little of the squashed air that’s giving you such a hard time and, consequently, gets a much easier ride. There is no effect on you at the front so you won’t find things any easier or go any faster but, by sharing the load - taking turns to draft and recuperate, the two of you can go for longer at a given speed than either of you could on your own (assuming, of course, that you are of similar ability). So even if you don’t draft when you are racing it is very useful for speed and endurance training - not to mention bike handling.

The big tow

It’s all pretty simple in theory but if you’ve ever tried cycle road racing, or joined the local chain gang, you’ll know that putting it into practice is quite another matter. For one thing you have to ride very close to the rider in front as the draft effect disappears as soon as you drop out of the ‘pocket’ and for another the pocket is invisible and it doesn’t stay in the same place!

The riding close bit comes only with confidence and practice but by the time you’ve finished reading you should have a pretty good idea of where it is that you need to be - just don’t try to practice it in non-drafting races!

The pocket itself might be invisible but the effects of the wind which creates it are normally pretty obvious - look at the way the grass is leaning, the way the flags, trees and leaves are blowing; feel which way it’s trying to push you.

The pocket moves because it’s affected by the direction of the wind. It’s always on the opposite side from the wind direction and moves further forward as the wind moves round to the side

The diagrams illustrate how the ‘apparent’ wind (in the direction of the dark arrow) is a combination of the draft created by forward motion (always parallel to the direction of travel) and the ‘real’ wind. The second guy knows where to ride to get the full benefit from his mate.

You should develop a pretty good sense of which direction you are travelling relative to the wind so you learn to anticipate where the pocket will be as the road changes direction. If you’ve been riding into a headwind and turn right, for instance, the wind will now be coming from the left hand side …and the pocket will be to the right.

Because the pocket is created by the combination of forward movement and wind there has to be a strong tailwind before there is no pocket at all. Once there is a strong tail wind, and the pocket does disappear, drafting becomes impossible which means that instead of making life easier a tailwind is often the hardest condition when you are riding fast in a group! There’s no help and nowhere to hide!

Once you are proficient at using the draft to recuperate you can start to use it to your advantage - to break away and build race winning gaps in drafting races and to speed up your training rides.

Friends and enemies

In a non-drafting race everyone is the enemy. In the drafting world, however, relationships are much more nefarious with temporary allegiances made and broken, and metaphorical cards played much more carefully. We’ll ignore the more sordid and negative aspects for now (getting rid of people, making life difficult for others, freeloading, intimidation) and look at how working together can turn a small advantage into a large one (and how to get real speed into your training)

The chances of finding somebody to ride as fast as he can with you drafting on his wheel, especially in a race situation, are, to say the least, remote. Breakaway groups work when everyone in them works: As soon as one member stops contributing the group is probably doomed. For a small group to stay away from a large pack everyone in it has to contribute and, most importantly, recuperate sufficiently to carry on contributing. What’s more, there is no time to make plans and no spare energy for getting things wrong. In other words it’s essential to know what to do …and to start doing it straight away. ‘It’ is called ‘Through-&-Off’ and it goes like this…

Getting it together

The riders start in single file, each in the draft of the one in front. (So the wind is from the right hand side for these guys - and if the fourth in line is not taking full advantage of the three in front)

The front-most rider moves to the side from which the wind is blowing and eases his pace ever-so-slightly. The rider behind continues at the original pace and passes the one who was in front.

Once he has passed him (gone through) he too swings to the side and eases his pace (goes off). And so the chain continues with each rider going through and off. The riders will now be in two parallel lines, one moving slightly faster than the other, with all of the riders in each drafting the ones in front.

The chain is complete when the original front rider is passed by the last rider. He must now accelerate and move across from the back of the slower line to the back of the faster one.

And so on… A couple of important points to emphasise are the need to ease off after swinging off (the next guy has to get past, remember) and the need to accelerate onto the back of the fast line.

For mile upon mile of fairly straight road this works a treat. For a break (or training ride) to really work, however, it must cope with corners, changes in wind direction, hills, descents, lapses in concentration, members taking a turn out to eat, riders getting dropped, parked cars, poor road surfaces etc. etc. The important thing is to get the group working properly again as quickly as possible and normally the way to do it is exactly as already described - the front person swings off towards the wind, the second in line goes through and off and the rest follow on.

Intimate behaviour

Groups of four or less can waste a lot of effort riding Through-&-Off - each rider is forever changing pace and spends half his time in the wind. It’s far more efficient to ride in just one line with the front rider periodically dropping to the back. The second rider goes through at the original pace but doesn’t swing off and doesn’t ease off. The rider who has dropped off must judge his pace as he moves back down the line. One the one hand he wants to do it as quickly as possible to get back into the draft of the last man, on the other hand he mustn’t slow down too much or he’ll miss him and waste valuable energy chasing to get back on - or worse, get dropped! The larger the group the larger the dilemma - groups of five or more should generally go for Through-&-Off.

The same in any language

Through-&-Off is often referred to ‘Chain ganging’ or as ‘Two Lines’, so if you hear that being shouted it means the same thing.

There’s plenty more to say about drafting. I referred only briefly to some of the tactics used in a competitive environment and there are plenty more. There are also good techniques for organising training groups so that riders of similar and differing abilities can train together effectively and enjoyably.


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