Connor Dunne

Somerset levels test scenario To isolate the impact of mass on flat-ground performance, Global Cycling Network (GCN) presenters Ollie Bridgewood and Connor Dunne conducted a controlled experiment on the Somerset levels. The trial compared power output against speed across two distinct runs. In the baseline run, the riders maintained a steady 200 watts in a standardized hood position. The second run introduced a 20 kg weighted vest to simulate dead weight, testing the hypothesis that while gravity is the enemy on climbs, inertia and rolling resistance dictate the flat-land struggle. Mechanical drag and rolling resistance Physics dictates that extra weight on the flat doesn't just slow you down via gravity; it increases the normal force on your tires. This leads to higher rolling resistance as the rubber deforms under the load. While Bridgewood noted that optimized tire pressure from Pirelli can mitigate some of this friction, the energy cost is real. However, the largest penalty for larger riders isn't the weight itself, but the increased frontal area. Larger riders typically possess more surface area, creating greater aerodynamic drag which requires more wattage to overcome at cruising speeds. Acceleration and inertia breakdown The most tactical impact of weight occurs during phase shifts. In the 0–40 km/h standing start tests, mass proved catastrophic. Dunne saw his acceleration time suffer significantly, struggling to reach top speed under the added 20 kg load. This reveals that in criteriums or races with frequent cornering, a heavier rider consumes far more