ROLLING AHEAD

Will optimising tyre choice for lower rolling resistance make you faster? Simon Smythe investigates

- Simon Smythe

If you’re riding on a smooth, flat road at 40kph, rolling resistance accounts for about 20 per cent of the total energy you’re putting into your bike. On a rougher surface like cobblestones, it’s likely to be more. Of the other resistances, you have to overcome, about 70 per cent (the exact amount varies depending upon a range of factors) is aerodynamic drag and around 10 per cent drivetrain friction.

A tyre with a low rolling resistance will roll faster for the same amount of energy input, whereas a tyre with a higher rolling resistance will provide a lower return in speed for your wattage. What does that mean in actual watts?

“Let’s say we have one tyre designed for a competition like the Continental Grand Prix 5000 and another designed for puncture resistance, like the Grand Prix 4 Season, says Jan-Niklas Jünger, Continental’s road tyre product manager. “You are riding at 40kph with this tyre, while next to you is your twin riding at 40kph with the Grand Prix 5000. He is pushing 25 watts less due to the tyres.”

In a road race, being able to sustain the same speed for less power means you can conserve energy for the critical moments. For time triallists, it means more speed for less power.

Optimised for low resistance