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.