The use of disc brakes in the professional peloton has been a divisive topic since the UCI announced a trial period in the 2016 season, and and one of the arguments against their introduction has been the time it would take to change a wheel.
Unlike rim brakes, where quick-release skewers and open dropouts allow for a quick wheel change, the thru-axle system in the disc wheel requires the mechanic to fully unscrew the punctured wheel's hub and replace it. There is a time penalty, but the Roompot mechanic shows it is not much.
Roompot Oranje Peloton are the only team so far this season to use disc brakes in competition, with all their riders at the Volta a la Comunitat Valencia and the Tour of Qatar riding with the SRAM HydroR model. It is from Qatar that the Dutch Pro Continental team have provided this video, which shows a rear wheel change on stage 4.
Ivar Slik is the rider who punctures, and we calculate that it takes mechanic Dennis Kreder 18 seconds to get him back up and running.
In comparison, Edvald Boasson Hagen's first wheel change took just 10 seconds.
Roompot's effort was not exactly sluggish, but it was nevertheless a good five seconds or so slower than what you'd normally expect with caliber brakes.
The video below from Shimano shows a day in the life of a neutral service mechanic at the 2014 Vuelta a España in which three wheel changes are performed. It takes 14 seconds for Andrey Lutsenko and Philip Deignan to get new rear wheels, and 8 seconds for Maxime Bouet, though his is a front wheel and he has the wheel out himself nice and quickly.
Obviously wheel change times are influenced by more factors than just the nature of the brakes, but, on this evidence, it would appear that the discs make things a few seconds slower, though probably not so much as to make for a convincing case against their use.