As a healthy and pollution-free form of micromobility, bikesharing is an important sharing economy intervention. We study whether the market entry of electric scooter platforms, a less effortful and convenience-focused genre of micromobility, caters to users which are currently untapped by incumbent bike-based micromobility services, or whether it has detrimental effects by significantly substituting from an otherwise preferred service. Our identification strategy exploits the natural experiment of staggered scooter introduction in Europe. Using trip-level data of a leading bikesharing operator we observe a drop in bicycle fleet utilization of 17.1% that is moderated by service level, population characteristics and weather-related factors. Substitution stems mostly from leisure-related usage,while utilitarian trips during rush hours are not affected. We contribute to the understanding of possible unintended consequences associated with the sharing economy and shed light on consumer choice in micromobility. We also offer practical insights for platform operators and policy makers.