Tyre choice is indeed extremely important and Swiss Side has spent a lot of time investigating tyre performance. For triathlon, aerodynamics is by far the most important performance parameter. In this respect, choosing a tyre which provides the best aerodynamic performance for your wheel is a high priority, in addition to rolling resistance and puncture protection. The sidewall tread pattern on the tyre is actually very important due to a complex aerodynamic effect called the „boundary layer transition“. The best aerodynamic tyre on the market right now is the Continental GP 5000 23c. This is just by chance! The worst aerodynamic tyres are slick (smooth) tyres with no sidewall tread. These tyres will destroy the aerodynamic performance of any wheel from any brand. Tubeless clincher tyres offer lower rolling resistance than clincher tyres with tubes. This is important because power is power, whether that be aerodynamic drag power, or rolling resistance power. The best tubeless tyres we have measured in the wind tunnel are the Schwalbe Pro One TT 25c and Continental GP5000 TLE 25c. Interestingly for the Schwalbe tyre, the 25c has the same aerodynamic performance as the Schwalbe Pro One TT 23c, but with lower rolling resistance so the 25c is the better choice.