The United States faces a serious struggle in Paris to keep hold of the 100m free crown taken back by Caeleb Dressel in Tokyo three years ago but its the rest who face a mighty fight when he and teammates combine for a 4x100m free force with cowbells on.

The American 100m free crew includes at least eight men on Team USA who are candidates for a heats swim ... and then, a starring role in the USA final quartet that will fire on July 27 as sprint stars in search of stripes that stretch back to starting blocks in 1938 (first world record for the U.S.) and 1964 (first Olympic title when the event was introduced) through one of the biggest ultimate-showcase bull runs in any sport, the 16-year-old World record will quake. 

It's a shiny suit standard: 3:08.24 - Michael Phelps (47.51) Garrett Weber-Gale (47.02) Cullen Jones (47.65) Jason Lezak (46.06).

The latter from Lezak remains the swiftest 100m free split in any relay and a thudding, assisted time and thrilling performance that highlights the staggering speed of the 46.14 mustered unassisted by material gains by Britain's Duncan Scott in textile suit as he swept past 2012 100m Olympic champion Nathan Adrian to deliver an historic gold ahead of the USA in the 4x100m medley relay at the 2019 World Championships.