Also, I now understand why long mudguards go so far round at the back - as the guy in front’s rear wheel sprayed up a 10ft fountain of ground water behind him.
Simple physics innit (although gravity and air resistance will complicate matters...). Two different length guards (red) and additional mudflap (green):
Simple physics innit (although gravity and air resistance will complicate matters...). Two different length guards (red) and additional mudflap (green):