What's a sticky bottle in cycling?
Often times you may hear the term "sticky bottle" thrown around the announcer's booth or on media related to cycling. The term refers to a team car providing a boost to a rider by having the rider latch onto the gel or bottle the rider is receiving from the car and not letting go.
While it's common for rider's to hold on for a second or two to the bottle to maintain balance on their bike as they grab nutrition from the team car, it's often the case this is abused and they hold on for a multitude of seconds to let the team car drag them along.
This often happens when a rider gets gapped from the peloton due to a mechanical bike issue or if they got caught up in a crash. While illegal, the penalties are often not enforced depending on how the commissaire of the race feels it affects the racing. It's a grey area however, and it's more common to be enforced if caught on camera. Nibali got disqualified from the 2015 Vuelta after his sticky bottle tactic dragged him back to the peloton in full view of the helicopter camera.
Race commissaires may also implement a "barrage" such that the team car can only drag the rider so far through a sticky bottle or motorpace (drafting behind the team car) and not completely back to the peloton.