Ceri JC

I'd have to say riding style. I used to get almost half my present mileage when the bike was just ridden for pleasure and I was locking and spinning up the rear wheel reasonably regularly. Now I can't remember locking or spinning up the rear for the past 2 years and hardly ever ride for pleasure. I presently commute reasonably swiftly, but with vastly less harsh braking and less full throttle acceleration from low speeds.