In cycling and for triathlon training, a chain gang is a group of riders in a tight formation drafting behind the lead athlete. The riders will often be split into two parallel lines behind the rider at the head of the pack, hence the chain gang name.
The lead rider is using more effort than the riders riding in their slipstream as he/she is more exposed to wind resistance. Some studies have shown that the riders in the pack can save up to 40% in effort than those at the head of the bunch and can reduce drag to as little as 5-10%.
The lead position in the pack is rotated throughout the ride to maintain a fast riding pace and let each rider recover. When the position at the head of the pack changes, the lead rider will swing to the side and let the rest of each line come through the middle, before the rider tucks back in behind the final rider in the line (mimicking the role of links in a chain).
While the majority of triathlon races are non-drafting events (where a chain gang formation would be against the race rules), performing a chain gang in training will have multiple benefits. These range from bike handling skills to endurance benefits, braking techniques and a clearer understanding of pacing.
You’ll also witness an increase in your ability to hold a high speed when riding at the front of the pack and learn about taking the fastest lines in the roads, as well as the responsibility of highlighting potholes and other road hazards to the group behind via hand signals.
Worth noting is that, for safety reasons, chain gang riding isn’t suitable for riding with aerobars/tri bars.