For cyclists, aerodynamic drag accounts for around 70% of the resistance to forward motion. It increases as the square of their speed and so will account for an even greater proportion of the effort at race speeds.But a cyclist riding in a pack experiences significantly lower aerodynamic drag than one riding solo.Published research suggests drafting can reduce drag by between 27% and 95%. Thats a massive decrease in energy expenditure and, in turn, enables a group of cyclists to ride significantly faster than a solo rider. A Tour de France breakaway only has a 2% chance of winning, so why join one?5% drag In the peloton, the team leader can rely on the support of their team. ASO/Charly Lopez Its even suggested that a rider in the centre of a pack could be experiencing only 5% of the drag of a solo rider; its not unusual to see a rider freewheeling for short periods when in the centre of a fast-moving peloton.Riders will usually only ride at the front of a bunch for part of a race and even on the front, riders experience a lower drag figure, with a reduction estimated at 10% or more, due to the air flowing over the following riders, rather than closing in behind them. A solo rider will have to work much harder for a longer period than one riding in the peloton. ASO In the bunch, the team leader will be surrounded by their support riders, or domestiques, enabling them to conserve energy for a decisive break or climb, while a sprint star will only come around their lead-out rider in the last few seconds of a sprint finish for the same reason.Domestiques also ferry food and drink to their team leader while in the bunch and will often lend their bike if the leader has a puncture or other mechanical issue, or pace them back to the peloton, so the bunch provides protection and support that a solo rider would not have. More Tour de France questions answered Why is the Tour de France not on ITV? 3,302km in 76 hours: how fast is the Tour de France? What is the Tour de France caravan, and why does everyone love it so much? Tour de France jargon buster: all the cycling terms you need to know to understand the race