Minimizing last mile delivery costs is of paramount importance for all shipping companies that strive to stay competitive on the market. A potential solution to the problem is the use of crowdsourcinga model where individuals voluntarily take on a task proposed by another entity (e.g. a company). In this paper, we present the results of a comparison of performance for three types of crowdsourced delivery fleets likely to be used in an urban setting. The fleets differ in the mode of transport the couriers use: bicycles, cars or both. The performance is quantified by the total number of deliveries made and the on-time delivery rates. Experimental results were obtained through a simulation that closely resembles real-world traffic conditions in a city with developed cycling infrastructure and takes into account the variations in the speed of couriers. The research shows that bicycle-based crowdsourced fleets outperform other kinds of fleets under simulated conditions. This makes them a faster, more environmentally-friendly and potentially cheaper alternative to traditional fleets that rely on cars.