a bicycle hub dynamo assembly is configured with a hub and a releasable electrical connector . the hub has a generator mechanism housed in a hub shell that generates electricity by rotation of the hub shell relative to a hub axle . the generator mechanism includes a first electrical connector with first electrical contacts . the releasable electrical connector includes mating electrical contacts configured to mate with the electrical contacts of the electrical connector that is fixed to the hub axle . the releasable electrical connector includes an inner housing part and an outer housing part with a fixing portion of the second electrical contacts retained between the inner and outer housing parts .