I did the the Ironman in 1983 in Kona, Hawaii; (Thank you Julie Moss). After the race, Valerie Silk, the official Ironman race founder, told me that the first ever Ironman was a race between friends to settle a bet as to which athlete was the most superior: The swimmer, the cyclist or runner? (the swimmer won.) With that concept in mind or keeping with the spirit of the race, the distances in a triathlon should be calculated in terms of time/distance for fairness.
A fair triathlon would have the following distances or distances determined by using these proportions: 1.5 kilometer swim (1 mile), 25 Kilometer bike (15 miles), 5 Kilometer run (3.2 miles)
An elite athlete in any of these events could finish in a time of around 15 minutes. Ergo the race would require all around athletes rather than running and biking specialists. This to me would improve the sport of triathlon greatly. It would be a fair race and make the finishes much more exciting with racers much closer together throughout a competition. It would also determine which sport produces the greater athlete. But readers of this blog all ready know the answer to that: The swimmer would win.