Wider tires generally reduce rolling resistance on rough roads because they change how the tire interacts with surface irregularities. Research by David Gordon Wilson at MIT explains that a larger contact patch at lower inflation pressure spreads deformation over a wider area, lowering energy lost to tire hysteresis. Andy Ruina at Cornell University emphasizes that dynamic interactions between tire carcass and road texture determine whether deformation energy is dissipated in the tire or returned to forward motion.
Mechanical causes
On rough surfaces most energy loss comes from repeated vertical deflection and bending of the tire carcass and the micro-suspension action between wheel and road. A narrow, high-pressure tire tends to slam into bumps, producing higher peak deflections and rapid flex cycles that increase hysteretic losses in the rubber and casing. A wider, lower-pressure tire flattens more against irregularities, reducing peak strain rates and converting some shock into slower, recoverable deformation. This does not mean lower pressure is always better; carcass construction, tread, and sidewall stiffness change how deformation is distributed.
Relevance, trade-offs, and consequences
For commuters, gravel riders, and people in regions with poorly maintained roads, the practical consequence is clearer: wider tires can improve efficiency and comfort simultaneously, reducing fatigue and—for e-bikes—extending range. From an environmental and territorial perspective, promoting appropriate tire choices for local road conditions can lower energy consumption across many trips and improve safety and accessibility in communities with rough infrastructure. Conversely, at high speeds on smooth surfaces aerodynamic penalties of wider tires become significant; competitive road cyclists may accept slightly higher rolling resistance to minimize drag.
Equipment selection therefore involves balancing tire width, pressure, and construction against intended terrain and speed. Field measurements and laboratory models discussed by Wilson at MIT and Ruina at Cornell University support the qualitative conclusion that on rough roads wider tires typically offer lower rolling resistance, but individual outcomes depend strongly on tire design and accurate pressure tuning. For precise decisions, riders and planners should consult controlled test data for specific tires rather than relying on width alone.