Jodie is the current Victorian Vets Criterium and Road champion in her age group. She has been racing for several years now and likes any event that involves sprinting and not too many hills. She initially used cycling as an important part of her rehabilitation from a mountaineering accident in New Zealand. She then got into racing as a replacement for martial arts in which she represented Australia and won Gold, Silver & Bronze medals in the Martial Arts World Games in 2000. I came across a great article on Chasing the breakaway by Chris Carmichael and thought I'd pass along and comment on his great insights
Breakaway riders have two ways to gather information about their status in the race. There's a motorbike with them that uses a chalkboard/whiteboard to display their current advantage over the field, and they have radio earpieces they can use to communicate with their team cars.
The team directors then calculate the speed the peloton needs to travel in order to catch the break and set up their team for the sprint. This is done by taking the speed of the break and determining the number of seconds it takes them to cover a km (say 75 seconds), then measure the time gap between the break and the peloton (say 90 seconds), and then determine how many seconds faster per km, the peloton must travel in order for the break to be caught within the distance from the finish to set up the sprint e.g. 2km.
This assumes the break will remain at a reasonably constant speed or perhaps a bit slower given they are usually working harder than the peloton.
I would like to thank Chris Carmichael for permission to publish information sourced from here.