The Tyre Factor

Swiss Side has spent a lot of time investigating tyre performance because this is extremely important. 

Choosing a tyre which provides the best aerodynamic performance is a priority. Clinchers perform better than tubular tyres. The sidewall profiling on the tyre is actually very important due to a complex aeroydynamic effect called the “boundary layer transition.” According to our testing, the best aerodynamic tyre on the market right now is the Continental GP 4000s II 23c. The worst aerodynamic tyres are smooth with no sidewall tread. Clincher tubeless tyres offer lower rolling resistance than clincher tyres with tubes. This is important because power is power whether that is aerodynamic drag power or rolling resistance power. The best tubeless tyre we have measured in the wind tunnel is the Schwalbe Pro One 25c. Interestingly, the 25c has the same aerodynamic performance as the Schwalbe Pro One 23c, but with lower rolling resistance. 

Posted by Fabienne Dirksen on

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  • Hi Ilkka

    Very good question! Yes, we spend a lot of time measuring both rolling resistance and aerodynamic drag because as you correctly say, the best tyre is the one which delivers the overall lowest power loss. Because the typical rolling resistance drum tests do not correctly represent how a tyre rolls on the road, (because the contact patch shape is very different on a flat road surface than it is on a round drum test surface), we indeed also use our instrumented bike and AeroPod devices for quantifying the best setup. What we currently see is that the Continental GP4000sII with latex tube, and the Schwalbe Pro One tubeless tyre (in tubeless setup) is equal in terms of overall power loss (aerodynamic drag + rolling resistance). The Conti is better in aero drag, the Schwalbe Pro One better in rolling resistance but within our measurement accuracy, the end result is that both tyres are equal.
    Tubeless tyres will eventually offer the best performance solution so stay tuned for new tubeless aero tyres! -We’ll be reporting on what is best and we will always sell the fastest setup on our website.

    Swiss Side on

  • Hi. Interesting information about tire aerodynamics. Tubeles tires are coming now and as you have posted earlier, they have lower rolling resistance than clinchers. Have you tested with your instrumented bike that is the gain from lower rolling resistance greater than the aerodynamic loss compared to Conti 4000GP tyres. Or have you tested how big of a difference is between Conti 4000GP 23mm and 25mm tyres. 25mm is atleast much more comfortable…

    Ilkka Westling on

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