In cycling, there's the "century", a 100 mile ride, the "metric century", which is 100km or 62 miles, and then there are the "double century" of 200 miles and the "double metric century" of 200km or about 125 miles.
Even though there might be metric mileage measurement, here in the US, it feels like elevation gain is always expressed in feet.
Well, measuring elevation gains in meters would be a big letdown relative to the effort expended.
Bicycle wheels/tires are often referred to in inches, but the underlying standards are milimeters (rather prime numbers at that). And gear ratios are usually measured in inches. Most bicycle measurements are in mm, but head tubes/steerer tubes are in inches, as with pedal axle threads and most common bottom bracket threads. In short bicycle standards have been a mixed bag for a long time.